Category: Food Safety

Preserving Summer Squash

Marlene Geiger 3 Comments

One zucchini, two zucchini, three zucchini . . . . four . . .

Summer squash is now in plentiful supply.  When a plant begins to produce, it often produces an overwhelming amount of produce.  While there are several varieties of summer squash, zucchini is the one we hear about the most.  And perhaps the one we have the most ‘fun’ with when surprise care packages show up on co-workers’ desk or neighbor’s doorstep. Before giving all away, consider saving a few for off-season use by preserving.

Assorted summer squash
Assorted summer squash – Photo: canva.com

Summer squash is at its very best when it is eight inches or less in length and an inch or two wide (about two to three days of growth) or, in the case of odd-shapes, picked right when the flower falls off. When picked and eaten at this size, the inside texture is consistent throughout the fruit, never pithy, and the seeds aren’t yet developed. The skin is incredibly tender, and the flavor is mild and sweet–sweet because the plant creates sugars as energy to make seeds; when picked before the seeds develop, those sugars are still present in the flesh. If left on the vine longer, the skin begins to toughen and quality decreases. When cooked the tender squash create uniform, never mushy or stringy, delicious additions to soups, kebabs, sauces, salads, and stir-fries. And, yes, they make a fine zucchini bread or zucchini cake, too.

Fresh squash should be washed in cold water to remove all visible signs of soil before using or storing. Handle carefully as summer squash bruise easily. Store fresh squash in the refrigerator crisper in plastic storage bags or rigid containers to retain moisture. Stored in this manner, squash will maintain quality for 5-7 days. 

So while we know how to use them fresh, what about preserving them?

CANNING
The USDA does not recommend canning summer squash or zucchini alone.  Rather the recommendation is to preserve by freezing, pickling, or drying.  An adequate processing times has not been established for a safe product.  Squash are low-acid vegetables requiring pressure canning to destroy the bacteria that cause botulism. The heat required to can squash results in the squash flesh turning mushy and sinking to the bottom of the canning jar. The compacted flesh does not heat evenly.  Zucchini may only be canned when paired with tomatoes using a tested recipe from The National Center for Home Food Preservation (NCHFP) OR paired with pineapple juice, sugar, and lemon juice for Zucchini Pineapple. Zucchini Pineapple maybe used in salads, desserts, or other recipes calling for crushed or chunk pineapple.

FREEZING
There are three different ways to successfully freeze summer squash./zucchini.  Begin by choosing young squash with tender skin and washing.  There is no need to peel but squash must be blanched before freezing.  Blanching slows or stops the enzyme action which can cause loss of flavor, color and texture.  Blanching also cleanses the surface of dirt and organisms, brightens the color, helps retard loss of vitamins and wilts or softens vegetables making them easier to pack. Blanching may be done in boiling water or steam.

  1. Slices – Slice ¼ – ½-inch thick.  Blanch in boiling water for 3 minutes on in steam for 4 1/2 minutes; cool in ice water for at least 3 minutes.  Drain well and package.  If packaged in freezer containers, leave ½-inch of headspace.  Slices may also be flash frozen using the tray method and packaged.
  2. Preparation for Frying – Follow instructions for blanching.  Before packaging, dredge in flour or cornmeal.  Flash freeze using the tray method and package.
  3. Grated for Baking – While some grate, package, and freeze squash for future baking, it is recommended to steam blanch squash for best quality.  Steam blanch small quantities of grated squash 1 to 2 minutes (until translucent) followed by packing measured amounts into containers.  Cool containers in ice water, seal and freeze.  When ready to use, thaw containers of frozen squash in the refrigerator prior to use. If the squash is watery when thawed, discard the liquid before using in baked goods.

Varieties for freezing include cocozelle, crookneck, pattypan, straightneck, white scallop and zucchini.  Chayote is also regarded as a summer squash but requires slightly different preparation for blanching.  Chayote is diced and seeded before blanching for 2 minutes. 

Remember to label and date packages. Properly packaged and frozen, squash should maintain high quality for approximately 10 months in the freezer.  Vacuum packaging can extend the shelf life of frozen squash but cannot be used as a food preservation method alone. Flash freeze squash slices before packaging, package frozen squash and return frozen squash to the freezer. Vacuum packaged frozen squash will have a longer shelf life than frozen squash which is not vacuum packaged.

PICKLING
Follow a tested recipe for pickling summer squash. Summer squash, zucchini, or chayote work well for pickling.  Two approved and very good tasting recipes can be found at the National Center for Home Food Preservation: Summer Squash Relish  and Pickled Bread-and-Butter Zucchini.

Notes:  Squash may be diced or shredded by hand instead of shredding with a food processor.  Any variety of onion is acceptable.  Celery salt may be used in place of celery seed for a taste preference.  Relish can be enjoyed freshly made without processing.  Fresh or opened jars of relish should be refrigerated. [Preserving Food at Home Resource Guide, PennState Extension, p.104] For best quality and safety, consume refrigerated pickled squash within 7 days.

DRYING
Varieties that work well for drying include zucchini and yellow summer squash.  Wash and trim ends from the squash and cut squash into ¼-inch slices.  Steam blanching slices for 2 ½ -3 minutes or water blanch for 1 ½ minutes is recommended for best quality.  Utah State University Extension suggests adding 1 teaspoon/gallon citric acid to the blanching water to reduce darkening during the drying process.  Drain the slices and arrange them in a single layer on a dehydrator tray. Dry in a food dehydrator at 135-140⁰F for 10-12 hours or until slices are leathery crisp and brittle.  Store the dried pieces in airtight containers (glass jars or in moisture and vapor-proof freezer containers, boxes or bags) in a cool, dry, dark place for up to 12 months. Vacuum packaging dried squash is also an option as it will resist moisture better and extend the shelf life.

Ten pounds of fresh squash will dry to approximately ¾ pound. Dried squash can be used in soups or stews or processed in a food chopper and used in breads or baked goods.

Regardless of how summer squash is preserved or used fresh, it is nutritious. One cup sliced (100 g), fresh summer squash has approximately 18 calories, 1 g fiber, and 1 g protein. Squash is an excellent source of vitamin C. Cooked squash will have essentially the same calories, fiber and protein, but will lose approximately 75% of the Vitamin C during the cooking process.

To learn more about the many uses for summer squash, check out: Summer Squash Is a Versatile Vegetable in Iowa Gardens.

References

Updated January 2024. mg.

Marlene Geiger

I am a graduate of the University of Nebraska-Lincoln with a BS in Home Economics Education and Extension and from Colorado State University with a MS in Textiles and Clothing. I enjoy spending time with family and friends, gardening, quilting, cooking, sewing, and sharing knowledge and experience with others.

More Posts

Food Preparation, Food Preservation, Food Safety ,
3 Comments on Preserving Summer Squash

Meat Thermometers – A Grilling Essential

Marlene Geiger
Steaks on the grill with thermometer to check internal temperature
Steaks on the grill with thermometer to check internal temperature.

Grilling adds a fun element to picnics and summer but it can also be a time of danger for food borne illness. It is not possible to tell if a food is fully cooked by simply looking at it. The only way to accurately measure if a food product is cooked to a safe minimum internal temperature is to use a food thermometer.  This is especially true when grilling meats; meat and poultry tend to brown quickly on the outside but may not have reached a safe internal temperature to prevent harmful bacteria from causing foodborne illness.

Know the Safe Internal Temperature

To insure cooking is both SAFE and GOOD TASTING, follow the guidelines below for safe minimum internal temperatures and rest time for meat, poultry, and seafood.

Date last reviewed: March 11, 2022. Source: FoodSafety.gov

Calibrate Thermometer for Accuracy

A properly calibrated meat thermometer is key for achieving both meat safety and quality. Imagine the indignation of serving undercooked meat followed by food borne illness because the thermometer didn’t read correctly or wasn’t in calibration.  Neither is a viable excuse for a food safety misstep.  Thermometers should be checked and adjusted on a regular basis using the ice-water method.  For a video demonstration of thermometer calibration, view How to Calibrate a Meat Thermometer courtesy of the North American Meat Institute and University of California Davis Cooperative Extension. 

Insert Thermometer Properly

To get a correct temperature reading, the thermometer must be inserted in the properly location.  Usually, this in the center of the thickest part of the food away from bone, fat, or gristle.  Use these guidelines on finding the right location: 

BEEF, PORK or LAMB ROASTS. The food thermometer should be placed midway in the roast, avoiding the bone. Irregularly shaped foods, such as beef roasts, should have their temperature checked in several places.

THINNER FOODS such as MEAT PATTIES, PORK CHOPS and CHICKEN.  The USDA encourages the use of digital instant-read thermometers for thinner foods as digital thermometers don’t need to be inserted as deep as dial thermometers and may be inserted sideways in the thickest part.    

Regardless of thermometer type, manufacturer’s instructions should be followed regarding depth of insertion to give an accurate reading.  If instructions are not available, check the stem of the thermometer for an indentation or “dimple” that shows the end of the sensing device. The probe must be inserted the full length of the sensing area. For dial thermometers, this is usually 2 to 3 inches and less for digital instant-read thermometers where the heat sensing device is in the tip of the probe.  About 15 to 20 seconds are required for the temperature to be accurately displayed with a dial thermometer and about 10 seconds is needed for a digital thermometer.

Additional Thermometer Tips

  • Use a clean thermometer for testing each time it is inserted into the food.  Follow manufacturer’s directions for washing before and after each use.
  • To prevent overcooking, begin checking the temperature toward the end of cooking but before the food is expected to be “done.”
  • Wait until toward the end of the cooking period before inserting a thermometer to prevent the possibility of transferring possible bacteria from the outside to the inside.  This will also help to prevent loss of moisture.

Use that food thermometer and grill safely!

Marlene Geiger

I am a graduate of the University of Nebraska-Lincoln with a BS in Home Economics Education and Extension and from Colorado State University with a MS in Textiles and Clothing. I enjoy spending time with family and friends, gardening, quilting, cooking, sewing, and sharing knowledge and experience with others.

More Posts

Food Preparation, Food Safety, Summer
Leave a Comment on Meat Thermometers – A Grilling Essential

Defrosting Trays

Rachel Sweeney

With the arrival of warmer weather and holiday weekends, you may be thinking about firing up the grill. Grilling is a great way to enjoy a variety of proteins, vegetables, and even fruits! Sometimes when grilling we are looking for a quick way to defrost items before putting them on the grill. However, it is important that food safety is also considered when you think about thawing these items.

Raw meat on defrosting tray
Defrosting tray with a piece of meat on it surrounded by various vegetables.

A caller recently posed a question about a defrosting tray she had used to thaw meat on her counter. This was the first time I had heard of this equipment, so I did some research. Defrosting trays are made from a material that has a high ability to conduct heat, such as copper or aluminum. When these trays are placed on your kitchen counter, they will quickly come to match the temperature in your kitchen.

Many defrosting trays are advertised showing how quickly they can melt an ice cube. However, the trays aren’t as efficient at melting dense items, like a steak. When a frozen food item, like a steak, is placed on the tray, the surface temperature of the steak will warm up at a slightly quicker speed as compared to being just on the counter, but the interior of the steak will remain frozen. Ultimately, this method for thawing will not result in significantly faster thawing as compared to just having the item on your kitchen counter.

The kitchen counter is not where we want to be thawing our frozen items, regardless of whether a defrosting tray is involved. This is because the temperature of our kitchen falls within the Temperature Danger Zone (40° – 140°F), which is the temperature range where bacteria multiply rapidly.

So, what is considered a safe way to thaw food? Frozen items can be safely thawed in the refrigerator, in cold water, in the microwave, or cooking from the frozen state.

  1. Refrigerator: place frozen items in a tray to catch any juices while thawing and place on the bottom shelf in your refrigerator. Food thawed in the refrigerator can be refrozen without cooking, although there may be some loss of quality.
  2. Cold water thawing: food must be placed in a leak-proof package or plastic bag and submerged in cold tap water. The water needs to be changed every 30 minutes so it continues to thaw.
  3. Microwave thawing: after thawing food in the microwave, plan to cook it immediately after thawing because some areas of the food may become warm and begin to cook during the thawing process.
  4. Cooking without thawing: it is safe to cook foods from the frozen state, just keep it mind it will take approximately 50% longer than the recommended time.

References:

  1. Everything You’ve Wanted to Know About Defrosting Trays https://www.thespruceeats.com/what-is-a-defrosting-tray-4782382
  2. What is a Thawing Tray https://enewsletters.k-state.edu/youaskedit/2018/04/16/what-is-a-thawing-tray/
  3. The Big Thaw – Safe Defrosting Methods https://www.fsis.usda.gov/food-safety/safe-food-handling-and-preparation/food-safety-basics/big-thaw-safe-defrosting-methods#:~:text=There%20are%20three%20safe%20ways,water%2C%20and%20in%20the%20microwave.

Rachel Sweeney

I graduated from Iowa State University with bachelor’s and master’s degrees in Dietetics and Exercise Science. I enjoy gardening, cooking and baking, food preservation, traveling, being outside, and spending time with my family.

More Posts

Equipment, Food Safety
Leave a Comment on Defrosting Trays

Remember to Vent

Marlene Geiger 17 Comments

A critical step to achieving proper pressure inside a pressure canner is allowing it to VENT. What does this mean?

Venting is also “exhausting” the canner, a process of letting steam (and air) come out of the canner through the vent pipe for a period of time before beginning the pressure processing time.  Air trapped in a canner lowers the processing temperature and results in under processing of low-acid foods.  To be safe, the USDA recommends that all types of pressure canners be vented 10 minutes before they are pressurized.

WHY VENT? 

It is STEAM, not water, that does the processing in a pressure canner. Low-acid foods (foods with a pH of 4.6 or higher such as all vegetables excluding tomatoes, meats, seafood, soups and sauces) are not acidic enough to destroy bacteria, their spores, and the toxins they produce or prevent the growth of botulinum bacteria in a vacuum.  The heat-resistant spores produced by C. botulinum can only be destroyed with the correct combination of temperature, pressure, and tested time. Temperatures in the range of 240°F to 250°F (115°C to 121°C) are needed to kill spores (USDA 2015). Water can get no hotter than the boiling point (212ºF, 100ºC), but steam can. Steam trapped in the canner increases the atmospheric pressure inside the canner causing the boiling point of water to increase to 240ºF-250ºF, the temperature needed to destroy bacteria and C. botulinum, that would otherwise be free to grow in a vacuum sealed jar.

In order to reach the optimum temperature to destroy botulinum bacteria, air inside the canner must be exhausted to allow space for a pure steam environment to build. There is a vast amount of air in a canner due to the space between the water level and the lid as well as the air that escapes from inside the jars and from the water. The most “jar air” comes from those with raw-packed foods.

Pressure canner releasing steam through vent port
Venting canner. Photo: USDA Complete Guide to Home Canning

HOW TO VENT

The vent or petcock is a short hollow pipe that sticks up above the canner lid.  When open, it allows air and steam to escape from the canner.  When closed, it holds steam inside. To vent a canner, leave the vent port uncovered or manually open the petcock (some older models).  After placing jars inside the warm canner and securing the canner lid, set the burner on high. Watch for steam to escape from the vent pipe. When a strong, visible, funnel-shaped steam cone emerges, set a timer for 10 minutes and let the canner continuously steam. After the 10 minutes, add the weight or counterweight to the vent or close the petcock to pressurize the canner.

WHAT HAPPENS DURING VENTING?

As the water boils inside the canner, the empty spaces become a mixture of steam and air. As steam increases, it pushes the air out creating a pure steam environment.  USDA processing times are based upon a pure steam environment which makes venting so very important.

In addition to venting, remember to adjust for altitude. Most recipes list processing time based on altitudes near sea level. To ensure the health of those who enjoy your foods, always use a tested recipe and follow instructions. Remember to VENT for 10 minutes to ensure that any and all microorganisms are destroyed.

Source: National Center for Home Food Preservation and USDA Complete Guide to Home Canning (2015)

Marlene Geiger

I am a graduate of the University of Nebraska-Lincoln with a BS in Home Economics Education and Extension and from Colorado State University with a MS in Textiles and Clothing. I enjoy spending time with family and friends, gardening, quilting, cooking, sewing, and sharing knowledge and experience with others.

More Posts

Equipment, Food Preservation, Food Safety
17 Comments on Remember to Vent

Are You Prepared for a Power Outage?

Marlene Geiger

Unsettled weather tends to bring about unprecedented winds, powerful storms and tornadoes causing personal loss, major damage and power outages. While personal loss and damage are devastating, power outages can be a major inconvenience.  To prepare and stay safe, it’s important to know steps you can take before, during and after a power outage.

Power lines and fallen trees after a storm.

Power outages can be over almost as quickly as begun, but some can last much longer — up to days or even weeks. This depends on the severity of the storm and what damage has been done to power lines and systems. A power outage disrupts everyday life as it shuts down communications, water, transportation and services, closes businesses, causes food spoilage, and prevents use of medical devices.

Given these potential disruptions, it’s crucial to consider the resilience of a home when looking to buy. As you explore properties, evaluating features like backup power systems, flood zones, and overall structural integrity becomes essential. Homes equipped with generators or in areas with robust infrastructure may offer added peace of mind. Additionally, researching the neighborhood’s emergency preparedness and local services can provide further assurance.

For those considering a move to Gwinnett County, GA, it’s important to use resources that provide comprehensive information about property resilience. Utilizing platforms like Gwinnett county, GA on ez Home Search can help you find homes that meet your specific needs and safety criteria. This tool allows you to access detailed property listings and neighborhood information, ensuring that you choose a home with the features necessary to withstand potential disruptions.

Before a Power Outage – Prepare

Preparation can keep the most important people in your world safe when bad weather hits.  Here’s some quick tips on how to prepare:

  • Have a plan that all family members know and understand. 
  • Take an inventory of items in the home and keep it up to date. Pictures are best.
  • Plan for alternative power sources and test in advance—batteries, portable generator (fuel), power banks.
  • Build an emergency kit that includes 3-days of non-perishable foods and bottled water; important medications; blankets; personal hygiene items; first aid supplies; flashlights.
  • Talk to your medical provider about medical devices powered by electricity and refrigerated medicines. Find out how long medication can be stored at higher temperatures and get specific guidance for any medications that are critical for life.
  • In addition to personal safety measures, it’s crucial to consider the impact of a power outage on your home’s essential systems. Devices like water pumps and HVAC units, powered by electric motors, are vital for maintaining comfort and safety. Companies like Palmers Electric Motors & Pumps specialize in ensuring that these systems remain functional, even during outages. Regular maintenance and having a reliable backup power source for these motors and pumps can prevent significant disruptions and protect your home from potential hazards during an extended power loss.
  • Place thermometers in freezers and refrigerators to monitor temperature when power returns.  A container of water (or ice cubes) in the freezer is also a good indicator of temperatures going above 32ºF.
  • Remove or secure items outside of the home that can blow or become weapons.
  • Trim tree branches overhanging a house and clean gutters.
  • Get a weather alarm with battery backup (keep batteries fresh) and/or sign up for weather alert notifications from local radio or tv stations.
  • Have your phone charged.
  • Freeze jugs of water.

During a Power Outage – Stay Safe

The lights are out, appliances, and all electrical equipment without battery or power backup have stopped running. Now what?

  • Report downed power lines. Do not touch down lines nor attempt to remove trees which may be tangled in downed lines.
  • Turn off and unplug all unnecessary electrical equipment, including sensitive electronics. Leave a lamp or night light connected to indicate when the power does come back on.
  • Turn off or disconnect any appliances, equipment or electronics you were using when the power went out. When the power comes back on, surges or spikes can damage equipment.
  • Keep refrigerator and freezer doors closed. Food is safe in a securely closed refrigerator for up to 4 hours. In a freezer it depends on how full it is — the fuller your freezer, the longer it can last. A full freezer can last up to 48 hours, and a half-freezer can last up to 24 hours. Place frozen jugs of water in refrigerator to help maintain coldness.
  • Avoid using candles and your phone more than necessary.
  • Prevent carbon monoxide poisoning when using generators, camp stoves or charcoal grills; these items should always be used outdoors and at least 20 feet away from windows. Never use a gas stovetop or oven to heat your home.

When faced with a power outage, it’s essential to understand the immediate actions needed to protect your electrical systems and maintain safety in your home. Alongside reporting downed power lines and ensuring that all unnecessary electrical devices are unplugged, it’s also a good time to assess your home’s electrical infrastructure.

Outages can sometimes expose vulnerabilities in your system, highlighting the importance of having a reliable electrical service to address any potential issues. This is where professional assistance becomes invaluable, ensuring that your home is not only safe during outages but also equipped to handle any surges when power is restored.

Engaging a trusted service provider like Dream Team Electric can help you prepare for and respond to electrical challenges effectively. Their expertise extends beyond simple repairs; they can assist in reinforcing your home’s electrical systems to withstand power fluctuations and surges. By scheduling regular maintenance checks and upgrades, Dream Team Home Services can ensure your home is ready for anything, from routine outages to more severe electrical storms.

Additionally, their knowledge about integrating battery backup systems and surge protectors can provide peace of mind, safeguarding your appliances and electronics against unexpected disruptions. With their support, you can focus on keeping your home safe and secure, knowing that your electrical needs are in capable hands.

After a Power Outage – Assess

Recovery begins.

  • Throw out any unsafe food, particularly meat, poultry, fish, eggs and leftovers that have been exposed to temperatures higher than 40-degrees F for two hours or more or that have an unusual odor, color or texture.  When in doubt, throw it out. For additional help with food after a power outage, visit Play It Safe With Food After a Power Outage .
  • If the power is out for more than a day, discard any medication that should be refrigerated, unless the drug’s label says otherwise. Consult your doctor or pharmacist immediately for a new supply.
  • Plug in appliances and electric equipment including sump pumps. Check to make sure each is working properly.  Note anything that is not working properly and report to your insurance agent.
  • Note damage done to home or property and report to your insurance agent.
  • Call AnswerLine at 800-262-3804 with food safety questions or water/mold clean up should water get into the home.

For more helpful information and tips, visit Ready.  One can never be reminded too often or be too prepared when storms strike and the power goes out.

Marlene Geiger

I am a graduate of the University of Nebraska-Lincoln with a BS in Home Economics Education and Extension and from Colorado State University with a MS in Textiles and Clothing. I enjoy spending time with family and friends, gardening, quilting, cooking, sewing, and sharing knowledge and experience with others.

More Posts

Consumer Management, Food Safety, spring, Summer ,
Leave a Comment on Are You Prepared for a Power Outage?

Meet Rachel Sweeney

Marlene Geiger

Rachel Sweeney is the newest member of the AnswerLine team!

Child giving a 4-H presentation
Rachel giving a 4-H baking presentation – Photo: rsweeney

AnswerLine is a new role for Rachel Sweeney, but Iowa State University Extension and Outreach is not. Rachel grew up on a diversified farm outside of Iowa City and was actively involved with Johnson County 4-H as a member of the Graham Champions 4-H Club. At an early age, she realized she could turn her interest in food and nutrition projects into a career, she decided to attend Iowa State University and major in that area graduating with bachelor’s and master’s degrees in dietetics and exercise science. After graduation, she spent a year in Nashville completing a dietetic internship at Vanderbilt University Medical Center.

Rachel’s began her professional career as an ISU Extension and Outreach human sciences specialist in Nutrition and Wellness, serving southeast Iowa for nearly seven years. In this role she led food preservation workshops, food safety trainings, and nutrition trainings for child care providers. After a brief stint as a retail dietitian, she returned to ISU Extension and Outreach as a program coordinator for Iowa 4-H Youth Development’s SWITCH (School Wellness Ingetration Targeting Child Health) program, an innovative school wellness initiative designed to support and enhance school wellness programming. After two years in this role, she got a new job title, MOM, in November of 2021, and a need to balance work and family life. AnswerLine provided the perfect opportunity for her to continue to work and enjoy her young family. One month into the job, Rachel says, “I have really enjoyed my first month on the job answering client’s questions and I look forward to continuing to learn and grow in this role to best serve the citizens of Iowa and Minnesota.”

When Rachel is not answering client questions via phone or email, she is likely with her family, 5-month old son, Thomas, and husband, Jim. She enjoys gardening, cooking and baking, food preservation, traveling, and being outside. As if she isn’t busy enough with work, family, and her many interests, she is also training for the swim portion of a half-Ironman relay-team competition in June! GO Rachel!!!!!

Rachel is a member of the Academy of Nutrition and Dietetics and stays involved with the Iowa Academy of Nutrition and Dietetics.

Marlene Geiger

I am a graduate of the University of Nebraska-Lincoln with a BS in Home Economics Education and Extension and from Colorado State University with a MS in Textiles and Clothing. I enjoy spending time with family and friends, gardening, quilting, cooking, sewing, and sharing knowledge and experience with others.

More Posts

Adult Learning, Child Development, Food Preservation, Food Safety, Recreation , ,
Leave a Comment on Meet Rachel Sweeney

Are Two-Piece Lids Really Necessary?

Marlene Geiger 3 Comments

The USDA and the National Center for Home Food Preservation (NCHFP) recommend and support the two-piece lid system even though one-piece and reusable lids are available.  Why use two-piece lids for canning?  

Lid assembly for canning jars
Lid assembly layers – jar rim, metal lid, metal screw band. Flat lid with sealing compound around the edge. Photo: University of Wisconsin – Madison Extension

The two-piece lid system (flats and screw bands) is the best option for home canners. They are easy to use, seal reliably, and easy to tell if the jars sealed. When researched guidelines are followed, the two-piece lid system safely replaces the vacuum system used for commercially canned foods.

The vacuum system is created by a self-sealing system consisting of a flat metal lid held in place by a metal screw band. A trough around the outer edge of the flat lid holds a rubber-like, plastisol sealing compound which acts like a gasket; heat causes the compound to flow slightly over the rim of the jar.  During processing, the gasket allows air to escape from the jar and then forms an airtight seal as the jar cools. 

To ensure safe home canned foods, follow these important tips for two-piece lids:

  • Use new lids (flats) each time; after the first use the lid will no longer seal effectively. With careful handling, canning jars and screw bands may be reused many times. 
  • Purchase your lids (flats) from reputable suppliers.
  • Buy only the quantity of lids (flats) that will be used in a year’s time—please don’t hoard.
  • Follow the manufacturer’s directions for preparing lids (flats) to make sure to get a good seal. Heating of most flats is no longer needed or recommended by manufacturers. In fact, heating may actually cause lid failure.
  • Carefully observe headspace requirements for the product.
  • Removed air bubbles inside the jar with a plastic or silicone spatula.
  • Make sure the rim of the jar is clean before placing the flat lid on the jar.
  • Tighten the screw band as specified by the manufacturer.  Usually this is fingertip tight, which means the first full resistance is felt using just your fingertips.
  • Check all metal lids carefully. Don’t use old (more than 5 years old), dented, deformed, or defective lids.
  • Do not re-use lids from previously canned foods.

One-piece, reusable, and previous used lids are not approved for home canning by the USDA as they may allow air to be trapped within the sealed jar permitting bacteria to thrive and spoilage to occur which can lead to illness and even death.   While one-piece lids are available for home canning, they were made for use in industry where very strict time and temperature controls are in place.  Because they do not allow air to escape properly in home canning, consumers have reported jar breakage and lids buckling.

Reusable canning lids have been around for decades [1]. Research conducted through the National Center for Home Food Preservation on the reusable lids revealed that the three types of reusable lids they tested had an acceptable seal and removed the necessary amount of air. However, despite these finding, it was still recommended that the traditional two-piece metal lid system be used to “ensure the highest confidence in sealing.” [1] While there is no data to indicate that these lids will not perform satisfactorily if the manufacturer’s instructions are followed explicitly, the USDA and NCHFP cannot recommend their use due to a lack of researched-based information about their performance.

Lastly, recommendations and recipes from the USDA and NCHFP are currently based on the two-piece metal lid system.  The recommendation does not come lightly; it is backed by a body of research documenting how well they work consistently for safe home canning.

Why take a chance?  USE TWO-PIECE LIDS for best results and safe food processing! 

Sources:
1G. Sivanandam. Evaluation and Comparison of the Sealing Performance of Three Major Types of Jar Lids Available for Home Canning. Thesis Project – University of Georgia.
Recommended Jars and Lids. National Center for Home Food Preservations (NCHFP)
Put a Lid on It, Best Practices for Using Closures for Home-based Canning, North Central Food Safety Extension Network.
Steps for Successful Home Canning, GH1452. University of Missouri Extension.
Put a lid on It, Best Practices for Using Closures for Home-Based Canning. University of Wisconsin-Madison Extension.

Marlene Geiger

I am a graduate of the University of Nebraska-Lincoln with a BS in Home Economics Education and Extension and from Colorado State University with a MS in Textiles and Clothing. I enjoy spending time with family and friends, gardening, quilting, cooking, sewing, and sharing knowledge and experience with others.

More Posts

Equipment, Food Preservation, Food Safety
3 Comments on Are Two-Piece Lids Really Necessary?

Should Food Be Stored Outdoors in Winter or in the Snow?

Marlene Geiger 3 Comments
Thermometer in winter snow
Thermometer in winter snow.

With cold winter temperatures, one might be tempted to store food outdoors or in the snow.  This may also be true if one experiences a power outage due to a winter storm.  While storing food outside or in the snow may work in a pinch, long term storage is not advised. 

Although it may seem like a good idea to use our giant outdoor “walk-in freezer” to store food, there are two main reasons why the cold or snow may not necessarily protect it safely.  For one, the outside temperature can vary by the hour even if snow is falling thereby not protecting refrigerated or frozen food properly. Further, frozen food can thaw when exposed to the sun’s rays even when the temperature is very cold.  Food may become too warm and foodborne bacteria could grow. Secondly, perishable items could be exposed to unsanitary conditions or to animals which may harbor bacteria or disease.  (Food that comes in contact with animals should never be consumed.)

Should the reason to take food outdoors or put in the snow be due to a power outage, the USDA suggests taking advantage of the cold weather to make ice by filling buckets or cans with water to freeze outdoors. The ice can be used to help keep food cold in the freezer, refrigerator or coolers. If one needs to temporarily store food outdoors, check the outdoor temperature and monitor the temperature and state of the food frequently. Food should also be stored in impermeable covered plastic containers and placed in a location that won’t be disturbed.

Meat, poultry, fish, and eggs should be stored at or below 40ºF and frozen food at or below 0ºF. While this is hard to maintain during power outages, the USDA says keeping your fridge and freezer doors closed as much as possible can help your food stay at the necessary temperature for up to four hours and longer in a cold room. If the doors stay closed, a full freezer can maintain temperature for up to 48 hours.

Marlene Geiger

I am a graduate of the University of Nebraska-Lincoln with a BS in Home Economics Education and Extension and from Colorado State University with a MS in Textiles and Clothing. I enjoy spending time with family and friends, gardening, quilting, cooking, sewing, and sharing knowledge and experience with others.

More Posts

Food Safety ,
3 Comments on Should Food Be Stored Outdoors in Winter or in the Snow?

Preserve Pumpkin and Squash Safely

Marlene Geiger 6 Comments
Assorted winter squash
Assorted winter squash.

Pumpkins offer far more than a fall porch decoration or carving medium for Halloween. Fall is the prime time to find and use sugar or pie pumpkins along with some winter squash varieties for cooking, baking, and preserving. The pumpkin puree purchased in a can at the store is actually made from a squash that’s less a “pumpkin” and more of a butternut squash in both flavor and texture.  It turns out, if you truly want the best pumpkin puree, don’t use an actual pumpkin.  The best “pumpkin” flavor comes from firm-fleshed winter squash varieties like Kabocha, Red Kuri, Butternut, New England Cheese Pumpkin, and pie/sugar pumpkin.  Avoid large jack-o-lantern varieties which are bred for size rather than flavor.

However, think safety when preparing or preserving pumpkins or squash. Pumpkins/winter squash are low acid vegetables and require special attention to preparation and processing. Use excellent sanitation in handling the fresh pumpkin/squash flesh.  Do not let cut or cooked pumpkin/squash sit out at room temperature for more than 2 hours during preparation or prior to preserving. 

Freezing Pumpkins and Winter Squash

Freezing is the easiest way to preserve pumpkin and winter squash and yields the best quality product. Select full-colored mature pumpkin/squash with fine texture (not stringy or dry). Simply wash the pumpkin/squash, remove the seeds and cut it into cooking-sized pieces.  Pumpkin/squash can be cooked in boiling water or pressure cooker, steamed, or baked in the oven with or without the rind removed.  Cook, steam or bake the pumpkin/squash until it is soft, remove the pulp from the rind and mash for baking; cubes can also be frozen if desired. Cool the pumpkin/squash as quickly as possible.  Package the puree in freezer containers sized for future use (2 cups of puree equals one can of pumpkin) leaving headspace and freeze. Remember to thaw the pumpkin in the refrigerator when ready to use. 

What if the pumpkin/squash is too hard to get a knife through? Smaller whole pumpkins/squash can be prepared in the oven or pressure cooker with no cutting required. Poke the vegetable with a knife to create steam vents. Bake or cook until tender; remove seeds and flesh, mash or puree. Another option is to use the microwave to soften the vegetable.  Begin by poking some steam holes in the vegetable.  Microwave for a few minutes until there is some give when pushed on.  Cool briefly, cut in half, remove seeds, and microwave, cut side down, until tender.  Lastly, the oven is an option.  Place the vegetable on a baking sheet and roast until there is some give when poked. Remove from the oven, cool briefly, cut in half, scoop out the seeds, and continue baking cut side down until tender.  Once the vegetable is tender, cool briefly to handle safely.  Scrap out the flesh, mash or puree.

Canning Pumpkins and Winter Squash

If you prefer to preserve pumpkin/squash for shelf storage, it must be canned with pressure and only safely canned in cubes. Canning pumpkin butter* or mashed or pureed pumpkin/squash is NOT recommended (see below). To pressure can cubed pumpkin/squash, first wash the pumpkin/squash and remove its seeds. Next, cut the pumpkin/squash into 1-inch wide slices, then peel and cut the flesh into 1-inch cubes. Blanch the cubes in boiling water for 2 minutes. Fill the canning jars with the cubes, and cover them with the hot cooking liquid leaving 1 inch of headspace.   Process at 11 pounds of pressure with a dial-gauge canner.  For altitudes below 2000 feet, process pints for 55 minutes and quarts for 90 minutes.  For a weighted gauge canner, process at 10 pounds of pressure at altitudes below 1000 feet and at 15 pounds of pressure above 1000 feet.  Process pints for 55 minutes and quarts for 90 minutes.

Canned pumpkin/squash can be used for side dishes, casseroles and soups.  It can also be used for pies and baking by pureeing at the time of use; however, it does not work as well for pie as frozen.

Skip the grocery-store can of pumpkin puree and instead make your own. It will be perfect for all your fall baking and cooking needs.

* Pumpkin Preserves.  Gelled preserves rely on the natural acidity present in most fruits for safe food preservation. Most fruits have natural acids so resulting jams or jellies can be safely canned in a boiling water bath process. Pumpkin, however, is a low acid vegetable and cannot be safely canned in the boiling water bath process. A jam or sweetened preserve would have to have enough sugar and/or added acid to be treated safely without concerns about botulism. A certain acidity level is also required to cause the pectin molecule to form a gel structure. At the present time, the USDA nor National Center for Home Food Preservation have any tested recipes to recommend for safely canning pumpkin preserves (jams, jellies, conserves, or pumpkin butter) and storing them at room temperature.  These pumpkin products must be stored in the refrigerator or freezer and treated the same as fresh pumpkin.


Source:
Canning Pumpkins and Winter Squash. Freezing Pumpkin. Freezing Winter Squash. National Center for Home Food Preservation.

Marlene Geiger

I am a graduate of the University of Nebraska-Lincoln with a BS in Home Economics Education and Extension and from Colorado State University with a MS in Textiles and Clothing. I enjoy spending time with family and friends, gardening, quilting, cooking, sewing, and sharing knowledge and experience with others.

More Posts

Fall, Food Preservation, Food Safety
6 Comments on Preserve Pumpkin and Squash Safely

Potential Deadly Canning Mistakes

Marlene Geiger 14 Comments

Home canning is an excellent way to preserve garden produce and share it with family and friends, but it can be risky—or even deadly—if not done correctly and safely.  The potential culprit is botulism. 

Although it’s a rare occurrence, botulism is a serious illness caused by a bacterium toxin, Clostridium botulinum, that attacks the body’s nerves. It can cause difficulty breathing, muscle paralysis, and even death.  Clostridium botulinum is commonly found in soil, on raw fruits and vegetables, on meat and fish, and many other foods and surfaces. Improperly home-canned, preserved, or fermented foods can provide the right conditions for the bacteria to make the toxin.  One cannot see, smell or taste the toxin, yet if ingested, even a small amount can be deadly. 

To avoid concerns about botulism, steer clear of these canning mistakes.1

Thumbs down and angry face emoji

Making Up Your Own Recipe
Use only up-to-date, scientifically tested recipes approved by the USDA and follow directions exactly.  Good sources are The USDA Complete Guide to Home Canning, the National Center for Home Food Preservation, So Easy to Preserve, and land-grant university publications.    Without scientific testing, there is no way to know how long the product needs to be processed to be safe.

Thumbs down and angry face emoji

Adding Extra Starch, Flour or Other Thickeners
Starches slow the rate of heat penetration into the product and can result in under processing.  Clear Jel® is recommended as a thickener for canned pie fillings. If a product is not as thick as desired going into the jar, it can be thickened at the time of use.

Thumbs down and angry face emoji

Adding Extra Onions, Chilies, Peppers, or Other Vegetables to Salsas or Sauces
Tested recipes specify the quantity of vegetables allowed to keep the salsa or sauce within the safe pH range.  Most vegetables are low-acid and adding extra vegetables will dilute the acidity and result in an unsafe product.  While it is dangerous to add more vegetables to salsa and sauce recipes, fewer may be used for a milder flavor.  Extra ingredients can be added at the time of use.

Thumbs down and angry face emoji

Canning by Electric Pressure Cooker, Oven, Open Kettle, Microwave, or Dishwasher
Boiling water bath or pressure are the only approved canning methods. Any other method should be avoided as foods will be under processed and unsafe. Heat is conducted by air in an oven which is less efficient than water or steam. As a result product temperature never exceeds the boiling point; jar breakage is also a possibility. Open-kettle canning, placing hot food in jars and sealing with no further heat treatment, has been considered an unsafe home canning practice since the 1980’s due to insufficient heat to destroy bacteria2. Microwaved food reaches 212°F but heating is not uniform; in addition, there is a danger of jar explosion within the microwave oven or as food is being removed3. The water temperature of the dishwasher’s cleaning and rinsing cyles is far below that required to kill harmful microorganisms. While electric pressure cookers use pressure for cooking, they do not meet the appliance standards for home pressure canning, even if marketed as safe for pressure canning. Washington State Extension explains all the reasons why electric pressure cookers should not be used for home canning in Canning in Electric Pressure Cookers.

Thumbs down and angry face emoji

Not Making Elevation Adjustments
The temperature at which water boils is affected by barometric pressure which is reduced with elevation or altitude. When water doesn’t reach the normal boiling temperature, undesired pathogens may survive the canning process. These pathogens could multiply in the canned food and cause sickness.  Processing times and temperatures for recipes in most canning resources are based on canning at an elevation of 1,000 feet above sea level or lower.  When canning at a higher elevation, one must add more pounds of pressure for pressure canning and more processing time for water bath canning.  See charts prepared by South Dakota State University Extension for altitude adjustments.

Thumbs down angry face emoji

Not Venting the Pressure Canner
Trapped air inside a pressure canner lowers the temperature obtained for a given pressure and results in under processing.  To be safe, the USDA recommends that all pressure canners be vented 10 minutes before they are pressurized.

To vent a canner, leave the vent pipe (steam vent) uncovered (or manually open the petcock on some older models) after you fill the canner and lock the canner lid in place. Heat the canner on high until the water boils and generates steam that can be seen escaping through the open vent pipe or petcock. When a visible funnel-shape of steam is continuously escaping the canner, set a timer for 10 minutes. After 10 minutes of continuous steam, you can close the petcock or place the counterweight or weighted gauge over the vent pipe to begin pressurizing the canner.

Inappropriate Amount of Water in Pressure Canner. Sufficient water is needed in a pressure canner to properly create steam, build pressure and distribute steam evenly throughout the canner; insufficient water will lead to uneven heating of the food in the jars and underprocessing. Lastly, there is danger of the canner running dry, breaking jars, and damaging the canner bottom. 2-3 inches of water is needed to provide sufficient steam but one should always follow the manufacturer’s direction. Two much water is also a problem. “The temperature of water in a pressure canner at 15 psi is ~213 deg F. The temperature of stem in a pressure canner at 15 psi is ~250 deg F. Clostridum botulinum spores are killed at 240 deg F. If jars are submerged in water while being pressure canned, the contents of the jars can only get as high as 213 deg F.”5

Thumbs down angry face emoji

Failure to Acidify Canned Tomatoes
Because the pH of tomatoes is an unknown, the USDA recommends that bottled lemon juice be used to lower the pH of the product to be unquestionably safe.

Thumbs down angry face emoji

Rushing the Pressure Canner Cool-Down Time
The natural cool-down of the canner is part of the tested processing time.  Hurrying this process will result in under-processed food and siphoning of liquid from the jars.  It may also cause jar breakage.

Thumbs down angry face emoji

Allowing “Hot Pack” Foods to Cool in Jars before Processing
Processing times are based on the food being hot at the beginning of the processing.  Foods not starting hot could be under processed. Further, the rule, “hot foods hot and cold foods cold” applies; when foods are held between 40 and 140°F, bacteria can grow rapidly.

Thumbs down angry face emoji

Processing Low-Acid Foods in a Water Bath
Canning low-acid foods requires special care. This includes red meats, fish, poultry and all vegetables (except for acidified tomatoes). Low-acid foods can support the production of the deadly botulism toxin if these foods are not processed properly in a pressure canner. A pressure canner heats food to high temperatures (240-250 degrees F or higher) and destroys the spores that produce the botulism toxin. A boiling water bath canner, which can be used for canning pickles or fruit, heats food to boiling temperature (212 F), which is not high enough to ensure safety for canning vegetables and other low-acid foods4.

Home canning is perfectly safe but needs to be done correctly.  If you are new to canning (or need a refresher), check out Safe Home Canning Basics, by University of Missouri Extension to learn about preventing botulism and other key issues to be aware of when preserving food by home canning.

Sources:

1Avoiding Canning Mistakes. Utah State University Extension.
2Say NO to Oven Canning. PennState Extension.
3Safe Home Canning Basics. Extension University of Missouri.
4Botulism: take care when canning low-acid foods. University of Minnesota Extension.
5UCCE Master Food Preservers of El Dorado County, Facebook post 2-29-2025.

Updated 2-2025, mg.

Marlene Geiger

I am a graduate of the University of Nebraska-Lincoln with a BS in Home Economics Education and Extension and from Colorado State University with a MS in Textiles and Clothing. I enjoy spending time with family and friends, gardening, quilting, cooking, sewing, and sharing knowledge and experience with others.

More Posts

Equipment, Food Preservation, Food Safety
14 Comments on Potential Deadly Canning Mistakes

AnswerLine

Connect with us!

AnswerLine's Facebook page AnswerLine's Pinterest page
Email: answer@iastate.edu
Phone: (Monday-Friday, 9 am-noon; 1-4 pm)
1-800-262-3804 (in Iowa)
1-800-854-1678 (in Minnesota)

Archives

Categories

Meta