Peel Tomatoes Before Preserving

Tomatoes can be preserved by freezing, canning, or drying with good results.
For best results, PEEL TOMATOES BEFORE PRESERVING.   

Peeling tomatoes is a step that many seem to loathe and consider an unimportant extra step. Perhaps it is the word ‘peel’ that makes the task distasteful as peel means to remove the outer covering or skin from a fruit or vegetable usually with a knife—like peeling an apple or a potato.  My grandma used the term, ‘slip the skin’ which really seems more appropriate for removing the skin from a tomato.  The process is simple:   dip tomatoes in boiling water for 30 to 60 seconds until skins split or wrinkle. Dip into cold water, slip off the skins and remove the cores.

Removing the skins is important for these reasons:

  1. The texture of the skin may be undesirable in the finished product.
  2. Most tested recipes for tomato products were prepared and tested with skins removed.  Since tested recipes are meant to be followed as written, leaving skins on would be an alteration of the recipe, and therefore, may not only influence the quality of the product, but also the safety.
  3. Skins may interfere with the necessary uniform heat penetration in the canning process.
  4. The skins of fruits and vegetables are sources of bacteria, yeasts, and molds.  Some of these contaminants are removed when the produce is washed with cool water but it is not possible to remove it all.  By peeling or slipping the skins, the bacterial load is greatly reduced rendering a safer final product.
  5. The tomato skin is heavy in a kind of nutrient called flavonols, which may impart a bitter flavor to a canned product.

So bite the bullet and slip those tomato skins.

For more information on freezing, canning, and drying tomatoes, check out How to Preserve Tomatoes by Utah State University Extension and Preserve the Taste of Summer, Canning and Freezing Tomatoes by Iowa State Extension and Outreach.  When canning tomatoes or tomato products, remember to acidify with commercially bottled lemon juice or citric acid to prevent the possibility of botulism.

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.

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Freezer Burn and Food Safety

Have you opened some frozen food to find it has a dry, grayish surface or lots of ice crystals clinging to the surface? This is freezer burn.   Freezer burn is simply the result of air coming into contact with food, and while it may not look appetizing, it is usually safe to eat.

The phenomenon of freezer burn happens when tiny ice crystals on the food’s surface evaporate directly into vapor without first going through the liquid water phase – a process scientifically termed sublimation. This moisture loss or dehydration leaves the food’s surface layers dried out and discolored.

Freezer burn happens when food is not adequately wrapped to remove oxygen, which has a bleaching effect on the food surface. Food stored constantly at 0 °F will always be safe. Only the quality suffers with lengthy or inadequate freezer storage.

The bleaching and moisture loss effect of freezer burn may not make food unsafe to eat, but it certainly affects the taste, texture, and color. Severely freezer-burned food will have an off taste and smell that is especially noticeable. It’s best to toss any food that exhibits severe freezer burn as the quality does not merit the effort to save or prepare it.  Products exhibiting mild freezer burn are usually fine to eat by cutting away the burned area either before or after cooking. Foods with a higher water content are more likely to get freezer burn.

A few simple precautions will help to avoid freezer burn and ensure frozen foods remain at peak condition at time of use and eliminate food waste.  Here’s some tips from the experts:

  • Use freezer-safe containers.  Only use bags, jars, paper and containers that are labeled for freezer use. These products are designed to keep air out.
  • Remove as much air as possible.   Air is the enemy of frozen food.  Vacuum sealers do a wonderful job of removing air.  However, squeezing the contents without smashing will also remove a lot of air.  Some people like to insert a straw into the corner of a zipper bag and pull air out before the final close.  If using freezer containers, crumple a piece of waterproof paper on top of the food to help minimize headspace. This helps prevent freezer burn, ice crystal formation and keeps food pieces from drying out.
  • Maintain the freezer temperature at zero degrees F or lower to help freeze food fast and stay frozen solid.  Foods stored near or in freezer doors or at the top of a chest freezer should be eaten first as these areas are for short-term storage.  Also avoid packing the freezer tightly; air must be able to flow freely around the food.
  • Let foods cool before packaging.  The USDA recommends cooling food as rapidly as possible, either in the refrigerator or in an ice bath.   Cold foods are less likely to trap steam inside the packaging.  Steam, like air, is detrimental to frozen foods as it turns to ice crystals.  Individual blanched vegetables, fruits, meat pieces, and baked goods are best if cooled and then flash frozen on baking trays (tray pack method) for an hour or two before packaging.
  • Store-packaging may be left on meat products but they should be over-wrapped in freezer paper, heavy duty foil or plastic wrap or placed in freezer bags prior to freezing for long-term storage.
  • Label and date.   Freezing keeps food safe almost indefinitely.  However, there are recommended storage times for best quality. Refer to and/or download the FDA Refrigerator and Freezer Storage Chart which lists optimum freezing times for best quality. 

Freezer burn affects food’s quality but not its safety. Even though the food is safe to eat, doesn’t mean one should. Freezer burn fundamentally changes a food’s chemical composition, affecting its flavor and texture.   All foods are susceptible to freezer burn but with proper packaging and freezer management, the problem can largely be eliminated.

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.

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Meat Thermometers – A Grilling Essential

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.

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Defrosting Trays

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

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.

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Remember to Vent

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 must 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.

Image Source: 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.

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Are You Prepared for a Power Outage?

Spring often brings unsettled weather.  This year has been no exception as Iowa and other parts of the country have already experienced 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 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.

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.
  • 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.
  • 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.

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.  For a quick visual reminder, see this short YouTube video prepared by Farm Bureau Financial Services. 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.

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Meet Rachel Sweeney

Rachel Sweeney is the newest member of the AnswerLine team!

Rachel giving a 4-H baking presentation.

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.

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Are Two-Piece Lids Really Necessary?

The past two years have been very frustrating for home canners as canners searched and scrambled for two-piece lids. Out of frustration and desperation to get garden produce into jars, canners turned to using lids from uncertain suppliers, one-piece lids, reusable lids, and sadly reusing lids from previously canned foods (definitely a NO! NO!).  It is hopeful that the canning lid supply and demand problem will be less in 2022, but it is not clear that the problem has gone away as the shelves of many reliable outlets remain void of lids at this time.

Despite the supply and demand issue with two-piece lids, the USDA and the National Center for Home Food Preservation (NCHFP) continue to recommend and support the two-piece lid system even though one-piece and reusable lids are available.  Why the recommendation? 

The two-piece lid system (flats and screw bands) is still the best option for home canners. They are easy to use, known to seal reliably, and easy to tell if the jars sealed. When researched guidelines are followed by users, the two-piece lid system safely replaces the vacuum system used for commercially canned foods with 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.
  • 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?  TWO-PIECE LIDS REALLY ARE NECESSARY

________________________________________

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. https://tinyurl.com/pj7ywjat

National Center for Home Food Preservation (NCHFP), Recommended Jars and Lids, https://nchfp.uga.edu/how/general/recomm_jars_lids.html

North Central Food Safety Extension Network, North Dakota State University, Put a Lid on It, Best Practices for Using Closures for Home-based Canning, https://www.ncrfsma.org/files/page/files/fn2028_put_a_lid_on_it_fillable_information.pdf

University of Missouri Extension, GH1452, Steps for Successful Home Canning, https://extension.missouri.edu/publications/gh1452

University of Wisconsin-Madison Extension, Put a lid on It, Best Practices for Using Closures for Home-Based Canning, https://fyi.extension.wisc.edu/safefood/files/2021/04/Closures_2021.pdf

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.

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What’s Your Elevation? Does It Matter?

While residents of most Midwestern States usually don’t think about their elevation, elevation affects cooking and baking as well as home canning.  As elevation rises, air pressure falls and water boils at lower temperatures.

Boiling water at 1014 Ft of elevation

When it comes to everyday cooking and baking, there are few noticeable effects of elevation until one reaches 3000 ft.  Higher altitudes present several challenges when preparing some foods. At higher altitudes, leavened products using yeast, baking powder/soda, egg whites, or steam rise more rapidly, may collapse, and may not be fully cooked. Because water boils at a lower temperature at higher elevations, foods that are prepared by boiling or simmering will cook at a lower temperature, and it will take longer to cook. High altitude areas are also prone to low humidity, which can cause the moisture in foods to evaporate more quickly during cooking. At altitudes above 3,000 feet, preparation of food may require changes in time, temperature or recipe.  For those that find themselves at higher elevations, Colorado State University and New Mexico State University have excellent tips and guidelines for successful baking and cooking.

Because water boils at 212°F at sea level and decreases about 1°F for each 500-ft increase in altitude, adjustments must be made when canning foods at home to ensure home-canned foods are processed safely. The amount of time that jars are held at a certain temperature during canning is important to producing a safe product. Processing times for most recipes are based on elevations of 0-1000 ft unless stated otherwise. When elevations are above 1000 ft, extra time is added for food processed in a water-bath canner.  For food processed in a pressure canner, extra pressure is added.  Both adjustments are needed to get to their respective safe processing temperatures for high acid and low acid foods. 

Each USDA process has an altitude table with it. In this example for Crushed Tomatoes from the USDA Compete Guide to Home Canning, 2015 edition, note that time is increased in 5 minute increments as altitude increases for boiling water canning and pounds of pressure is increased for pressure canning. (Crushed Tomatoes is one example a food that can be processed by either boiling-water bath or pressure.)

While time is adjusted for water-bath canning, pressure regulation differs by the type of pressure canning equipment used—dial- or weighted-gauge canner as noted in the chart. (To be considered a pressure canner, the USDA recommends that a canner be large enough to hold at least 4 quart jars.) Pressure canners have either a dial gauge to indicate the pressure or a weighted gauge to indicate and regulate the pressure. Weighted gauges are designed to “jiggle” several times a minute or to rock gently when they are maintaining the correct pressure. If a dial-gauge canner is used, the gauge needs to be checked each year for accuracy.  If the gauge reads high or low by more than two pounds at 5, 10 or 15 pounds pressure, it should be replaced. If it is less than two pounds off in accuracy, adjustments can be made to be sure you have the required pressure in your canner [NCHFP]. Gauge testing is available at some county extension offices; contact your local extension office for testing availability. See Testing dial pressure canner gauges for more information [University of Minnesota Extension].

Elevation does matter in all aspects of food preparation, but especially so in home canning. Before beginning the canning process, it should be a priority to find and know your elevation.  It is quite easy to find your elevation using one of these sources:

  1. Visit a web page about your town or city;
  2. Use an online tool such as https://whatismyelevation.com;
  3. Use a smartphone app such as My Elevation;
  4. Refer to an elevation map for your state showing approximate elevations such as this one by Iowa State University Extension and Outreach from the Preserve the Taste of Summer series.

To learn more about elevation, watch this YouTube video by UnL Extension Food & Fitness.

To learn more about safe water-bath or pressure canning practices, watch these videos produced by South Dakota State University:

How to Use a Water Bath Canner video
How to Use a Pressure Canner video

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.

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Should Food Be Stored Outdoors in Winter or in the 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.

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