Transcript Water Bath Canning - Food Safety and Health

Hot Water Bath Canning
Why do we want
to preserve foods
at home?
How do we preserve foods?
Refrigeration and Freezing
Heat Processing
canning, pasteurization, blanching
Fermentation
Control of Moisture
drying, adding sugar or salt
Heat Processing
Blanching
Short heating to stop enzymes, soften tissue,
prevent color loss and remove air from tissue
Pasteurization
Mild 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
2 Types of Canning
Hot Water Bath
Canner
processes foods at 212˚F
used only for high acid foods
fruits, pickles
Pressure Canner
processes foods at 240˚F or
250˚F
used for low acid foods
meats, vegetables
High or Low Acid?
Magic Number ...
low pH
high acid
water bath
canner
<
4.6
pH
high pH
>
low acid
pressure
canner
ONLY!
Food pH less than 4.6
– fruit, pickled products
– boiling water canning is sufficient to
destroy cells of Clostridium botulinum;
spores no problem
Food pH greater than 4.6
– meat, vegetables, poultry, fish
– use pressure canner to heat at HIGH
temperature to destroy Clostridium
botulinum spores
Food
pH
egg white
shrimp
milk
corn, melon
peas, potatoes
chicken, meat
cheese
bananas, figs
tomatoes
pears, peaches
apples
lemons, limes
8.0
7
6.6
6.3
6.2
6
5.5
4.6
4.0 – 4.6
3.5 - 3.9
3.1
2
Strawberry Jam
Salsa
high acidity = hot water bath
Equipment
Jars
• 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 presterilized – full rolling boil for 10 minutes
Lids
• 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
Proper Canning Practices
Select good quality food
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
Prepare jars and lids
• 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!
Hot Pack vs Raw Pack
Raw pack
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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
Filling jars
• Fill jars with hot food
• Headspace
space between underside of lid and top of food
• Remove air bubbles
use a flat plastic or wooden spatula
• Place lids
wipe jar rim with a clean wet rag before placing
heated lid
• Tighten screw bands
fingertip tight
Canning
• 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.
Removing jars
• 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 hours
do not disturb!!
• After cool, test seals
• Storage
remove screw bands
wash lid and jar to remove any residue
label and date
store in clean, cool, dark, dry place
SALSA
High Acid
Tomatoes
– use only high quality fruit
– use paste tomatoes for a thicker product
– add tomato paste or drain off excess liquid
if using a slicing tomato
Low Acid
Peppers
– substitutions okay, but keep the amount the same
Onions, garlic & other veggies
– don’t increase before canning
Common Questions
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Favorite cookbook recipes
Salsa is too thin
Substituting peppers
Adding more onions or garlic
Pressure canning salsa
Using quart jars
Jams & Jellies
4 components for success
1. Fruit - top quality, ripe fruit
2. Acid - needed for gel formation
3. Pectin - carbohydrate that forms a
gel
4. Sugar - providing sweetness and
quality
Pectin
•
•
•
•
Some fruits have enough natural pectin for
jams and jellies
Commercial pectin made from apples or citrus
fruits
Powdered or liquid, not interchangable
Advantages to added pectin
Fully ripe fruit can be used
Cooking time is shorter and predetermined
Greater yield from a given amount of fruit
•
Store in a cool, dry place so it will keep it’s
gel strength. Use within one year.
Tips for success
• Use the proper pectin
– Powdered and liquid are not interchangeable
• Don’t skimp on sugar
– Use low- or no-sugar pectin if desired; artificial
sweeteners aren’t recommended
• Make small batches
• Pre-sterilize jars
– Destroys yeast and mold
When things just don’t
work…
Remake Instructions
OR
Syrup!
Common Questions
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Fruit floats to top
Moldy Jam
Paraffin
Hot water bath
Others?
Approved 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