Lets Get Ready to Preserve

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Lets Get Ready to Preserve!

• Barbara Ingham
• Extension Food Scientist
• www.foodsafety.wisc.edu

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Todays topics

• Why preserve foods?
• What are the basic food preservation guidelines?
• What resources are available to help you get
  started on a successful food preservation season?

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Take a minute to consider.Why do we preserve
foods?
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Why Preserve Foods?

• Increase the shelf life of food.
• Provide convenience.
• Retain the nutritional value.
• Improve how food tastes.
• And because its fun!

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Canning, Freezing and Drying

• Which method will you choose?
• Our aim safe, high quality food.

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Fight Food Spoilage

• Prevent mold, yeast and bacteria from growing on
  your food
• Prevent bruising and wilting
• Prevent changes in flavor and texture

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Food Preservation Quiz
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Methods in Food Preservation

• Refrigeration and Freezing
• Fermentation or Acidification
• Control of Moisture
• Drying
• Adding sugar or salt
• Heat Processing
• Canning, pasteurization, blanching

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Refrigeration and Freezing

• Refrigeration 32º to 40ºF
• S L O W S deterioration
• Freezing 0ºF or below
• S T O P S microbial growth and most deterioration
• Rapid freezing is best

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Fermentation Acidification

• Fermentation
• Sugar Acid
• Acidification
• the addition of acid to lower the pH and raise
  the acidity
• vinegar, lemon juice, citric acid

Microbes
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Control of Moisture

• Removing water (drying)
• Adding sugar
• Adding salt
• If water is not available, microbes can not grow

bind up the water
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Heat Processing

• Blanching
• Short heating to stop enzymes, soften tissue,
  prevent color loss and remove air from tissue
  (vegetables)
• Pasteurization
• Mild heat treatment designed to stop enzymes, to
  destroy growing bacteria, and to kill yeast and
  molds (milk, juice, pickles, jam)
• Canning
• High heat to destroy harmful microbes (meat,
  vegetables)

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Two Types of Canning

• Boiling Water Canning (212F) fruits and
  acidified foods
• Pressure Canning (240F or above) meats and
  vegetables
• Rememberadjust for elevation!

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How do we know how long to Heat Process food?

• 1. What is the pH of the food?
• below pH 4.6 above
• Time and Temperature work together
• Low temperature-long time
• High temperature- short time

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What is magic about pH 4.6?

• IF the pH of the food is above 4.6
• IF there is no oxygen present
• IF the temperature is warm
• ? Clostridium botulinum can grow and produce
  TOXIN (botulism poisoning)

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Recipe for Danger

• 1 Food, pH above 4.6
• 1 Vacuum seal
• 1 Room _at_ standard temperature
• ADD
• C. botulinum spores
• WAIT! You dont need to add these, they are
  everywhere!

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• Conditions for neurotoxin production
• Spores of C. botulinum
• No oxygen
• pH greater than 4.6

?Growing cells produce TOXIN
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What does this mean for home canning?

• Foods with pH above 4.6 that you want to can
• ? Process in a pressure canner to destroy spores
  of C. botulinum.
• ?Adding pressure increases temperature
• 10 psi 240 degrees
• 15 psi 250 degrees

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Botulism Strikes Spokane Mother, Two Children
February 28, 2009

• The Associated Press reported that three people
  in Spokane, Washington, have become ill from
  botulism. The botulism apparently occurred from
  improper canning techniques used in home-canning
  of green beans vegetables from a private home
  garden.
• The woman was a nurse in her 30s with two
  children under ten. She became ill enough to be
  put on a ventilator the children suffered milder
  symptoms. The incident was linked to difficult
  economic times.

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Dont harm your family with these canning methods

• Boiling water canning of low-acid food
• Open-kettle canning
• Oven canning

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Dont Forget

• Process at the correct temperature
• Follow an up-to-date, research tested recipe
• Adjust for elevation

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And now a word aboutcanners vs cookers

• Pressure canners and pressure cooker are NOT
  necessarily the same thing.
• Pressure canners must hold 4-Qt jars.
• Pressure cookers are NOT recommended for home
  canning.

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Will preserving food at home save you money?

• Do you have a ready supply of fresh produce or
  meat?
• Do you have canners and jars?
• Do you have a working freezer with plenty of
  space?
• Do you have the time.?

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Getting StartedEquipment

• Assemble Boiling Water and Pressure Canners
• Check dial gauges and rubber gaskets
• Inspect jars, rims lids
• Purchase freezer containers
• Clean your dehydrator

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Getting StartedProduce

• Start with tested varieties
• Harvest at the proper stage of maturity
• Discard diseased produce
• Rapidly chill harvested produce

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Getting StartedRecipes

• Use ONLY up-to-date, research-tested recipes!
• Dont (necessarily) do what your Mother told you!
• Current canning instructions
• date from 1994 or later.
• Time to leave creativity behind!

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Sources of Recipes for Home Canning

• Wisconsin Safe Food Preservation series (2008)
  foodsafety.wisc.edu
• Ball Blue Book (2006)
• So Easy to Preserve (2006)
• USDA Complete Guide to Home Canning
  www.uga.edu/nchfp

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Canning and Preserving for Special Diets

• Choose recipes that dont require sugar or salt
  for safety
• Read the recipe carefully
• Dont choose your own substitutions

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How Long Does It Keep?

• Canned foods- 1 year
• Frozen foods- meats 3 to 9 months, fruits and
  vegetables 1 year
• Dried foods- fruits and meat 6 months, and
  vegetables 1 year

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Publications

• Safe Canning Methods B2718
• Using and Caring for a Pressure Canner - B2593
• Wisconsin Safe Food Preservation series
  publications

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Next Time

• Monday, May 18
• 12 noon 1 pm
• Storing Fruits and Vegetables
• Tips on handling fresh fruits and vegetables for
  safe, high quality storage.