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Learn why and how we preserve foods at home through methods like refrigeration, freezing, heat processing, and fermentation. Discover the process of hot water bath canning for high-acid foods and the use of pressure canners for low-acid foods.
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How do we preserve foods? • Refrigeration and Freezing • Heat Processing canning, pasteurization, blanching • Fermentation • Control of Moisture drying, adding sugar or salt
HeatProcessing • 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
Hot Water Bath Canner processes foods at 212˚F used only for high acid foods fruits, pickles 2 Types of Canning Pressure Canner processes foods at 240˚F or 250˚F used for low acid foods meats, vegetables
4.6 pH High or Low Acid? Magic Number ... high pH low acid pressure canner ONLY! low pH high acid water bath canner < >
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
FoodpH egg white 8.0 shrimp 7 milk 6.6 corn, melon 6.3 peas, potatoes 6.2 chicken, meat 6 cheese 5.5 bananas, figs 4.6 tomatoes 4.0 – 4.6 pears, peaches 3.5 - 3.9 apples 3.1 lemons, limes 2
Strawberry JamSalsa high acidity = hot water bath
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 pre-sterilized – 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 • 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
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 SALSA • Low Acid • Peppers • substitutions okay, but keep the amount the same • Onions, garlic & other veggies • don’t increase before canning
Common Questions • Favorite cookbook recipes • Salsa is too thin • Substituting peppers • Adding more onions or garlic • Pressure canning salsa • Using quart jars
4 components for success Fruit - top quality, ripe fruit Acid - needed for gel formation Pectin - carbohydrate that forms a gel Sugar - providing sweetness and quality Jams & Jellies
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.
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 Tips for success
When things just don’t work… Remake Instructions OR Syrup!
Common Questions • 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