Canning Foods at Home Safely

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In this program….. • Food safety issues • Things to think about when canning • Food safety concerns when canning • 10 tips for canning food safely at Home

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Why preserve food?

• Store good quality food for later use – May be an economic advantage

• Protect food from spoilage – mold, yeast and bacteria

• Keep food safe so it does not cause a foodborne illness

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Food Spoilage

• Caused by microbes (a.k.a. bugs or germs) • Caused by physical changes (bruises or

punctures in a food) • Caused by enzymes found in fruits and

vegetables (need to be inactivated so taste and texture changes do not occur)

Food spoilage = money wa$ted

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Bacteria

• Can cause food to spoil • Can cause foodborne illness • Bacteria have different requirements for living

– Oxygen vs. No oxygen – High pH (low acid foods like vegetables and meat are

liked best by bacteria

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How Canning Preserves Food • Canning

– Heat destroys bacteria and inactivates enzymes – The seal formed during canning keeps other germs

from re-contaminating the food

• Pickling – Makes a food more acidic so

it is harder for bacteria to grow

– Canning (processing) destroys other bacteria and seals the lids

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How Food Preservation Works

• Jams and Jellies – Sugar binds the water; germs are not able to use

the water – Canning, freezing or refrigeration helps prevent

surface contamination by yeast or mold

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Should I can? Things to Consider: • Food

– What are the safest methods for preserving? – Which methods yield the best results? – What is your skill level? Do you have the time?

• Storage capacity – Do you have shelf space in a pantry

• Cost – What equipment do you have available? – Cost of equipment (canner & tools)

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Basic Equipment for Canning

Lid lifter Jar lifter Funnel

Jar wrench – NOT RECOMMENDED

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Don’t get bugged by deadly germs • Clostridium botulinum

– Commonly found in the soil; come in 2 forms • Vegetative cells (active cells – produce a deadly toxin)

– Anaerobic (live without oxygen) – Killed by boiling in water (212 degrees)

• Spores (often in the soil; inactive; in hibernation) – Spores can only be killed if they are boiled at 240 degrees

(must be done with a pressure canner)

– This bacteria loves a low-acid environment (think meat and vegetables!)

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How botulism can be a problem

Fresh green beans with inactive spores.

These green beans were canned in a waterbath canner instead of pressure canner. The lids sealed, creating an Anaerobic (no oxygen) environment. This environment causes the spores to wake up and become active. They divide, become overpopulated and start to die. When that happened, they produced the botulism toxin.

The green beans are now contaminated with the botulism toxin. You can’t see the toxin!

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The pH of a food determines which canning method you can safely use

pH = < 4.6

High Acid Foods Pickles Apricots Apples Raspberries Apricots Strawberries Oranges Blueberries Grapefruit Blackberries Peaches Pineapple Grapefruit Kraut Plums Pears Figs

pH >4.6 Low Acid Foods

Okra Beans Hominy Squash Potatoes Olives Pumpkins Spinach Shrimp Carrots Asparagus Clams Turnips Green peppers Meat Cabbage Poultry Peas Beets Corn Onions

WATER BATH CANNER PRESSURE CANNER

Source: So Easy to Preserve, 5th edition, University of Georgia, 12

Keep You and Your Family Safe!

Follow these food safety tips when canning foods at home.

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Food Safety Tips for Canning Food at Home

1. Always begin food preservation with clean hands, a clean preparation area, clean equipment and the freshest foods available. Jars will be inspected for nicks, cracks and rough edges before used.

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Food Safety Tips for Canning Food at Home

2. Always use a pressure canner when canning low-acid foods (pH > 4.6).

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Food Safety Tips for Canning Food at Home

3. Get the dial gauge on your pressure canner checked and tested each year.

More than half of home canners do not test their gauges on a yearly basis! Source: University of Georgia, 2002

More than 1/3 of gauges tested in Nebraska over 25 years tested too high, too low or were unable to be tested. Source: University of Nebraska, 2006

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Food Safety Tips for Canning Food at Home

4. Only use tested recipes with up-to-date researched processing times.

5. Never alter tested recipes. - Exception: if you live at a high altitude (> 1,000 feet),

you have to adjust processing times

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Why adjust processing times for altitude?

• At high altitudes, water boils at a lower temperature. Even though the water is boiling, the heat is not high enough to kill bacteria.

• By boiling longer or raising the pressure, we can assure that any bacteria will be killed.

• Use tested recipes and guidelines for canning at higher altitudes.

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How high altitude changes processing times

Food Jar size Usual time (< 1000 feet) 1001-3000 ft 3001 - 6000 ft

Water bath canning

Crushed tomatoes

quart 45 minutes 50 minutes 55 minutes

Jelly quart varies Add 1 minute of processing time per 1,000 ft of altitude

Pressure canning

Green beans quart 25 minutes Process (canning) time depends on altitude and type of pressure canner (dial vs. weighed gauge)

Source: So Easy to Preserve, 5th edition, University of Georgia, 19

Where to get Tested Recipes

YES!

Current Extension publications

USDA Manufacturers of home

canning equipment & ingredients.

NO!

Personal internet sites Cookbooks (esp. old ones) “Back to nature”

publications Out-of-date Extension

publications

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Food Safety Tips for Canning Food at Home

6. When filling jars, be sure to use the correct headspace.

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Food Safety Tips for Canning Food at Home

7. Check jars for sealed lids and reprocess those that do not seal within 24 hours.

This jar of pears sealed the first time it was processed.

This jar of pears had to be reprocessed (canned) a second time.

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Food Safety Tips for Canning Food at Home

8. Label lids with date and batch number.

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Food Safety Tips for Canning Food at Home

9. Periodically check jars for signs of spoilage. If spoilage is present, do not use them.

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Food Safety Tips for Canning Food at Home

10. For best quality, use home-canned foods within one year.

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For more information:

• So Easy to Preserve (University of Georgia Cooperative Extension) – http://www.uga.edu/setp/

• National Center for Home Food Preservation – http://www.uga.edu/nchfp/

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Questions?

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