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 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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Preserve Pumpkin and Squash Safely

Pumpkins offer far more than a door-stop at 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. 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: National Center for Home Food Preservation. 2015. “Home-Preserving Pumpkins.” https://nchfp.uga.edu/tips/fall/pumpkins.html.

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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Preventing Crystals in Grape Jelly, Jam, Syrup, and Juice

After you’ve gone to the trouble of foraging wild grapes or picking domestic grapes, juicing them, straining the juice, and making and processing juice, syrup, or jelly/jam, the last thing you want to find are crunchy bits in the jelly or syrup or a hard crystal formation at the bottom of a jar of juice. 

These crunch bits are crystals, usually of three types.
1) Tartrate Crystals – the naturally occurring components of grape juice
2) Sugar Crystals – improper cooking of the jelly or jam when the sugar is added.
3) Evaporation Crystals – loss of liquid

What are Tartrate Crystals?

Grape juice differs from many other fruit juices in that it contains naturally occurring amounts of both potassium and tartaric acid. At temperatures below 40F, these substances bind together to form crystals of potassium bitartrate better known as tartrate crystals. The crystals are benign or harmless so they pose no food safety risk but they are certainly unwanted encounters in juice, syrup or jellies.   Tartrate crystals can also form in grape jam.  In the wine industry, they are known as wine diamonds.

Preventing Tartrate Crystals

Regardless of the grape variety, color, or how the grapes were acquired, the problem is easy to solve with time and a fine strainer.

After juicing and straining the juice, allow the juice to sit undisturbed in covered containers for 24 – 48 hours in the refrigerator. My personal experience is that 48 hours is better than 24 hours if one has the time as crystals have continued to form in my juices after 24 hours. After the wait, slowly pour the juice through a jelly bag, cheesecloth, or very fine strainer into a clean container.  Be very careful as you reach the bottom as that is where you will find the tartrate crystals; they will appear as a rough, cracked substance on the bottom of the container.  Most of the crystals will be stuck to the container, but some may still be afloat.   

Once the tartrate crystals have been filtered out, the juice is ready to turn into jelly, syrup, or juice without the unwanted tartrate crystals. Recipes for jelly, jam, syrup, and juice can be found at the National Center for Home Food Preservation. The juice can also be frozen to be used later for making jelly.

What are Sugar Crystals?

Sugar is a crystal in its natural state and has an affinity to return to that form.  Even when dissolved in liquid as they are in jams and jellies, sugar molecules like to form into groups or crystals.  All they need is a party starter like an undissolved sugar crystal as a nucleus to draw other molecules of sugar towards it, re-forming crystals. Sugar crystals are not unique to grape sweet spreads. When making a sweet spread product or syrup regardless of fruit, it is important that the sugar is completely dissolved with no traces of crystals.

Preventing Sugar Crystals

Crystals throughout the jelly may be caused by too much sugar in the jelly mixture or cooking the mixture too little, too slowly, or too long. Learn how to prevent them from this Penn State Extension video.  Sweet spreads exhibiting sugar crystals are safe to eat.

Evaporation Crystals

Speckled crystals that form at the top of a sweet spread and scatter downward come when the product has been opened and allowed to stand; these crystals are caused by evaporation of liquid. This is more likely to happen with poorly capped, refrigerated jam or jelly.  White, fluffy mold on the surface of a jelly or jam is a sign of spoilage and should be discarded.

Crystallization due to evaporation can sometimes be reversed by gently reheating. Too much heat will cause the product to break down and not reset. The jar can be placed in hot water or carefully microwaving enough to melt the crystals. If melting is successful, a fresh or clean jar should be used.  Adding a small amount of lemon juice or corn syrup may also fix it.  In all cases, it is a temporary fix and the product usually goes back to crystallizing shortly.  A tight fitting lid is the best prevention. 

With just a little patience and careful preparation, crystals of all types can be prevented in grape products.

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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Potential Deadly Canning Mistakes

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].

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 Complete Canning Guide, 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.

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.

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.

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 bacteria [2]. Microwaved food reaches 212°F but heating is not uniform; in additon, there is a danger of jar explosion within the microwave oven or as food is being removed [2]. 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.

Not Making Altitude 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.

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. [3]

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.

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.

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.

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 foods.[4]

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 Minnesota University Extension to learn about preventing botulism and other key issues to be aware of when preserving food by home canning.

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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Canned Tomatoes – Answers to Frequently Asked Questions

Tomatoes are the most popular food for canning at home.  They are versatile, abundant, and easy to can. There is no doubt that tomato canning season is here as the number of “tomato canning” questions rise—floating, separation, loss of liquid, air bubbles.  Do any of these problems affect the safety?   AnswerLine is here to answer these questions.  

Float

Floating tomatoes (tomatoes or tomato pieces at the top of the jar, liquid at the bottom) may be a visual disappointment but does not affect the safety of the product. Floating is more likely to happen with whole or quartered tomatoes and with a raw pack.  The floating is caused by the natural air and water in the tomatoes which releases during processing. Raw food has a lot of air in it. The volume of food put in a jar before processing might actually only be ¾ food and ¼ air trapped inside the food. During processing, this air will escape from the food and rise to the top of the jar. Float can be minimized by choosing fresh, firm tomatoes, reducing the amount of liquid in the jar (replacing with product), packing the jar as firmly as possible without crushing the tomatoes, removing air bubbles, and using a regular mouth jar. Sometimes turning the jars upside down after they have cooled for 24 hours and letting them rest for a period of time will bring the liquid and solids back together.  Canning crushed tomatoes and/or using a hot pack often eliminates the problem. 

Separation

Sometimes crushed or puréed (juice) tomatoes will separate in the jar into tomato solids and liquid. Separation is another visually disappointing issue that does not affect safety. When tomatoes are cut or crushed before heating, exposure to the air activates a natural enzyme, Pectose (Pectinesterarse), found in high concentrations in tomatoes. The enzyme is activated when tomatoes are cut. This enzyme breaks down pectin which causes the liquids and solids to separate.  Heating tomatoes immediately after they are cut or crushed to 180F (82C) inactivates this enzyme.  This is the reason that many tested recipes direct one to cut small quantities of tomatoes and heat them in batches.  Gently shaking the jars after the product has cooled for 24 hrs may bring the solids and liquid back together.

Loss of Liquid

Loss of liquid does not cause food to spoil, though the food above the liquid may darken. If, however, the loss is excessive (for example, if at least half of the liquid is lost), refrigerate the jar(s) and use within 2 to 3 days.[1]  And jars with milder liquid loss should be used sooner rather than later so place them at the front of the shelf so they get used first.  Penn State Extension advises on the three likely causes of liquid loss or siphoning from the jar during processing of tomatoes or other fruits and vegetables—raw pack, rapid fluctuation of temperature in the canner, and removing the jars too quickly after processing. In addition to the causes noted, improper headspace and loose bands are other sources of liquid loss.  Food expands during processing and if a jar is overfilled there is insufficient room for the expansion.  When this happens, water will push out to make room for expansion. If canning ring bands are too loose, liquid will escape and may also cause seal failure. And like floating and separation, removing air bubbles from the jar prior to lidding helps to lessen liquid loss.

Air Bubbles

Removing of air also known as de-bubbling prior to processing is an important step in canning. Air trapped in jars can interfere with the jar’s ability to drive out the extra air in the top causing too much headspace, floating, loss of liquid, and a poor or no seal. Additionally, too much air space results in canned product above the canning liquid which can lead to discoloration and the development of off-flavors. Ball and Norpro make a bubble remover and headspace tool designed for air removal but a plastic or silicone knife or spatula handle will do the same; any tool used should be heat resistant to handle the heat of a hot pack.  Do not use anything metal to remove air as it may cause hairline cracks in the jar.  Simply run a bubble popper around the edges of the jar, gently shifting the food, so that trapped air is released as much as possible. After the air bubbles have been removed, more liquid may need to be added to the jar to ensure proper head space.

After processing, tiny air bubbles may be noticed in the product.  If these bubbles are inactive, they are benign or harmless.  If the bubbles are actively moving or fizzing up to the top of the jar when opened, the product may be fermenting or contaminated. Products with active air bubbles should not be used and properly discarded.

Despite one’s very best efforts to diminish floating, separation, loss of liquid, or air bubbles, it seems that there is one more non-scientific reason—the phase of the moon! Or that it just happens!  As long as the jar seals and there is at least half of the liquid in the jar, the tomatoes are safe inside the jar.

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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The Case for Bottled Lemon Juice in Canning

Many home preservers often wonder why tested and USDA approved canning recipes call for bottled lemon juice. This is especially true when it involves tomatoes and making jams.  Why not fresh squeezed lemon juice?

A USDA RECOMMENDATION

It is a USDA recommendation that bottled lemon juice be used.  And consistent with the recommendation,  reputable canning sources will agree that the best source of lemon juice for canning is commercially bottled lemon juice, as opposed to the juice of a fresh lemon.  The reason for the recommendation is that bottled lemon juice has been uniformly acidified or standardized per FDA regulations: “lemon juice prepared from concentrate must have a titratable acidity content of not less than 4.5 percent, by weight, calculated as anhydrous citrus acid.”  With a guaranteed pH (5 percent2), there is a consistent and known acid level which is essential for the critical safety margin in canning low-acid foods and for making jams gel properly.  

Acid strength is measured on the pH scale. The scale starts with strongest acid at 1 and declines in strength as the number increases to 14, the strongest alkali. The lower its value, the more acid in the food. The neutral point is 7, neither acid nor alkaline.  The amount of acid in canned food is critical to deter the growth of micro-organisms and insure that the food is safe. Foods with a pH less than or equal to 4.6 are labeled “high-acid” foods. Those with a pH greater than 4.6 are “low- acid.” This distinction is very important because only high-acid foods can be processed safely in a boiling water bath. Low-acid foods must always be processed in a pressure canner; if not, they can support the growth of the potentially harmful bacterium, Clostridium botulinum.

The pH of fresh lemon juice is inconsistent due to variety, maturity, weather conditions during growth, soil, fertilizer, rootstock, and storage conditions. There are even variations in acidity within a single variety. Lemons grown in hot climates tend to be less acidic than those grown in cooler climates.  Lemon juice contains both ascorbic and citric acid; since ascorbic acid is destroyed by heat, only citric acid is measured.  The average acid level of fresh lemon juice is about 5 percent, thus the “natural strength” labeling on the lemon juice bottle. 

While acid consistency is the reason for using bottle lemon juice, bottled lemon juice is made from concentrate and preserved with sulfites. For people allergic to sulfites, bottle lemon juice may be a health hazard.  If you or family members have a sulfite sensitivity or allergy, substitutes for bottled lemon juice include bottled lime juice (not Meyer or key lime) or frozen lemon juice (not lemonade) in equal amounts as bottled lemon juice or citric acid in appropriate ratios. Citric acid, sold as a white crystalline powder and not the same as ascorbic acid, is available where canning supplies are sold. It can safely be used to acidify foods if used correctly. Vinegar should not be used to replace bottled lemon juice unless a tested recipe allows it because white vinegar is weaker in acid strength. Equal amounts of bottled lemon juice can be used to replace white vinegar in recipes calling for vinegar, but not the reverse. When vinegar is an acceptable substitute, it will affect the flavor of the food.  Never change the amount of acid, dilute with water, or substitute acid sources unless the recipe specifically allows you to do so.  Aspirin should not be used as a substitute in canning. It cannot be relied on to lower pH or prevent spoilage [3].

ACIDIFYING TOMATOES FOR SAFE CANNING

When canning products with an unknown pH as acid foods, they must be acidified to a pH of below 4.6 with lemon juice or citric acid. Tomatoes, usually considered an acid food, and figs are two examples where the pH values hover near or above 4.6. When acidified with lemon juice or citric acid, they may be processed as acid foods [1][2] making them safe for boiling water bath or atmospheric steam processing. Directions from the National Center for Home Food Preservation [3] for acidification of tomato products to insure safe acidity in whole, crushed, or juiced tomatoes state:  Use 2 tablespoons of bottled lemon juice or 1/2 teaspoon of citric acid per quart of tomatoes. For pints, use 1 tablespoon bottled lemon juice or 1/4 teaspoon citric acid. Acid can be added directly to the jars before filling with product. Sugar may be used to offset the acid taste, if desired. 4 tablespoons of a 5 percent acidity vinegar per quart may be used instead of lemon juice or citric acid. However, vinegar will likely cause undesirable flavor changes. Tomato salsas must also be acidified.[4] To get an idea of how much difference bottle lemon juice makes, see Table 1 in the publication Why Add Lemon Juice to Tomatoes and Salsas Before Canning? by North Dakota State University.

pH MATTERS WITH JAMS

While many factors are involved in getting jams to “set” or gelatinize, pH plays a key role. When fruit is cut and heated with sugar, pectin strands are released from the fruit cells.  The freed pectin strands repel each other because they carry a negative electric charge.  Lemon juice lowers the pH of the jam mixture and neutralizes the negative charges on the strands of pectin allowing them to move together into a network to “set” the jam.  The optimal pH for gelatinization is between 2.8 and 3.5. The best way to achieve this level of acidity is to use commercially bottled lemon juice.  A second reason for using bottled lemon juice in jam recipes is to prevent the growth of bacteria and insure safe canning. With a lower pH, jams can be processed in a boiling water bath for a small amount of time dependent on altitude. 

Whether using bottle lemon juice to acidify tomatoes or getting jam to “set,” bottled lemon juice has a ‘best used by’ date. Keeping the product in the fridge may extend its date but it is best to use a fresh bottle when canning or making jam to insure that the juice is at its best.

The verdict is in.  The best way to insure a safe or desired pH for canning low-acid foods or jam gelatinization is to go with a commercially bottled lemon juice. Bottled juice is controlled and standardized with the acid content assured and more reliable than fresh lemons.  Fresh lemons, however, make excellent lemonade!

_____________________________

1 Code of Federal Regulations (Title 21, volume 2, revised April 1, 2010)

2 Green, Janet; Hertzberg, Ruth; Vaughan, Beatrice (June 2010). Putting Food By, Fifth Edition (p. 119). Penguin Books Ltd. 

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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