How do we preserve How do we preserve foods?foods?
Refrigeration and Freezing
Heat Processingcanning, pasteurization, blanching
Fermentation
Control of Moisturedrying, adding sugar or salt
HHeeaatt ProcessingProcessing
BlanchingShort heating to stop enzymes, soften
tissue, prevent color loss and remove air from tissue
PasteurizationMild heat treatment designed to stop
enzymes, destroy growing bacteria and kill yeast and molds (milk, juice, pickles, jam)
Canning (commercially sterile)High heat to destroy harmful microbes
Pressure Cannerprocesses foods at 240˚F or
250˚F used for low acid foods
meats, vegetables
Hot Water Bath Canner
processes foods at 212˚Fused only for high acid
foodsfruits, pickles
2 Types of Canning2 Types of Canning
High or Low Acid?High or Low Acid?
Magic Number ...
low pH
high acid
water bath
canner
< >high pH
low acid
pressure cannerONLY!
4.6
pH
Food pH less than 4.6 Food pH less than 4.6 – fruit, pickled productsfruit, pickled products– boiling water canning is boiling water canning is
sufficient to destroy sufficient to destroy cellscells of of Clostridium botulinumClostridium botulinum; spores ; spores no problemno problem
Food pH greater than 4.6 Food pH greater than 4.6 – meat, vegetables, poultry, fishmeat, vegetables, poultry, fish– use pressure canner to heat at use pressure canner to heat at
HIGHHIGH temperature to destroy temperature to destroy Clostridium botulinum Clostridium botulinum sporesspores
Food pHegg white 8.0shrimp 7milk 6.6corn, melon 6.3peas, potatoes 6.2chicken, meat 6cheese 5.5bananas, figs 4.6tomatoes 4.0 –
4.6pears, peaches 3.5 -
3.9apples 3.1lemons, limes 2
• use threaded home-canning jars with 2-piece lids
• free of cracks and chips• wash empty jars in hot soapy water
and rinse well before use• if your process time is under 10
minutes in a water bath canner, jars must be pre-sterilized – full rolling boil for 10 minutes
Jars
• use 2-piece lid with a self-sealing lid and ring
• use lids within 1 year of purchase
• follow manufacturers directions in preparing lids for use
• do not use old, dented, deformed lids
Lids
Pre – heating the Canner
• Fill boiling water bath canner with correct amount of water and begin heating
• Can adjust water level after adding jars
• 1 – 2 inches above tops of jars
• Check jars to be sure they are free of nicks and cracks
• Wash jars and screw bands in hot soapy water
• If processing time is under 10 minutes, sterilized jars by boiling for 10 minutes
• Heat flat lids as directed by manufacturer
remember to use new lids each time!
Prepare jars and lids
Hot Pack vs Raw Pack
Raw pack• unheated foods packed directly into jars• boiling hot water, syrup or juice poured over food • packed tightly to adjust for shrinkage during processing• will tend float in jars due to less air removed (especially
fruit)• better suited to processing vegetables in a pressure
canner
Hot pack• food heated to boiling, simmered 3 – 5 minutes• hot food packed into jars, boiling liquid added • best way to remove air• increases amount of food added to each jar• over time, color and flavor will hold up better than raw
packed foods
Enough syrup, water or juice to fill around the solid food and cover the food
• Fill jars with hot food• Headspace
space between underside of lid and top of food
• Remove air bubblesuse a flat plastic or wooden spatula
• Place lidswipe jar rim with a clean wet rag before placing
heated lid
• Tighten screw bandsfingertip tight
Filling jars
• Fill canner half full of hot water and begin heating before preparing food.
add a splash of white vinegar to water to prevent hard water build-up on jars
• Place jars in rack on bottom of canner.• Add more boiling water, if necessary.
water should be 1 – 2 inches above tops of jars
• Cover canner and start timing when water returns to a vigorous boil.
• When recommended time is up, turn off heat and remove the canner lid. Wait 5 minutes before removing jars.
Canning
• Remove jars with lifter, one at a time• Place hot jars directly on dry towels
leave one inch of space between jars during cooling
• Cool 12 – 24 hoursdo not disturb!!
• After cool, test seals• Storage
remove screw bandswash lid and jar to remove any residuelabel and datestore in clean, cool, dark, dry place
Removing jars
High AcidHigh AcidTomatoesTomatoes
– use only high quality fruituse only high quality fruit
– use paste tomatoes for a thicker productuse paste tomatoes for a thicker product
– add tomato paste or drain off excess liquid add tomato paste or drain off excess liquid
if using a slicing tomatoif using a slicing tomato
SALSASALSA
Low AcidLow AcidPeppersPeppers
– substitutions okay, but keep the amount the samesubstitutions okay, but keep the amount the same
Onions, garlic & other veggiesOnions, garlic & other veggies
– don’t increase before canningdon’t increase before canning
? Favorite cookbook recipesFavorite cookbook recipes? Salsa is too thinSalsa is too thin? Substituting peppersSubstituting peppers? Adding more onions or garlic Adding more onions or garlic ? Pressure canning salsaPressure canning salsa? Using quart jarsUsing quart jars
Common QuestionsCommon Questions
4 components for success4 components for success
1.1. Fruit - top quality, ripe fruitFruit - top quality, ripe fruit2.2. Acid - needed for gel Acid - needed for gel
formationformation3.3. Pectin - carbohydrate that Pectin - carbohydrate that
forms a gel forms a gel 4.4. Sugar - providing sweetness Sugar - providing sweetness
and qualityand quality
Jams & JelliesJams & Jellies
• Some fruits have enough natural pectin Some fruits have enough natural pectin for jams and jelliesfor jams and jellies
• Commercial pectin made from apples or Commercial pectin made from apples or citrus fruitscitrus fruits
• Powdered or liquid, not interchangablePowdered or liquid, not interchangable• Advantages to added pectinAdvantages to added pectin
Fully ripe fruit can be usedFully ripe fruit can be used
Cooking time is shorter and predeterminedCooking time is shorter and predetermined
Greater yield from a given amount of fruitGreater yield from a given amount of fruit
• Store in a cool, dry place so it will keep Store in a cool, dry place so it will keep it’s gel strength. Use within one year.it’s gel strength. Use within one year.
PectinPectin
• Use the proper pectinUse the proper pectin– Powdered and liquid are not interchangeablePowdered and liquid are not interchangeable
• Don’t skimp on sugarDon’t skimp on sugar– Use low- or no-sugar pectin if desired; Use low- or no-sugar pectin if desired;
artificial sweeteners aren’t recommendedartificial sweeteners aren’t recommended
• Make small batchesMake small batches• Pre-sterilize jarsPre-sterilize jars
– Destroys yeast and mold
Tips for successTips for success
Remake InstructionsRemake Instructions
OROR
Syrup!Syrup!
When things just don’t When things just don’t work…work…
? Fruit floats to topFruit floats to top? Moldy JamMoldy Jam? ParaffinParaffin? Hot water bathHot water bath? Others?Others?
Common QuestionsCommon Questions
Approved ResourcesApproved Resources
• Wisconsin Safe Food Preservation Series www.wisc.edu/foodsafety/
• Ball Blue Book (1997 edition or later)
• USDA Complete Guide to Home Canning &
• National Center for Home Food Preservation www.uga.edu/nchfp
• So Easy to Preserve www.uga.edu/nchfp