Department of Family and Consumer Sciences 1 Preserving Natures Bounty Principles of Home Canning
Department of Family and Consumer Sciences 2
3 How Canning Preserves Foods Control growth of undesirable microorganisms –Bacteria –Molds –Yeasts Control activity of enzymes Control –Reactions with oxygen –Moisture Loss
Department of Family and Consumer Sciences 4 Proper Canning Practices Carefully selecting and washing fresh food Peeling some fresh foods Hot packing many foods Adding acids (lemon juice or vinegar) to some foods
Department of Family and Consumer Sciences 5 Proper Canning Practices Using acceptable jars and self- sealing lids Processing jars in a boiling- water or pressure canner for the correct time
Department of Family and Consumer Sciences 6 Not recommended Open-kettle canning Microwave canning Dishwasher canning Oven canning Open-kettle canning
Department of Family and Consumer Sciences 7 Temperatures F – low acid foods –Pressure canning –Kills bacterial spores F – high acid foods –Water-bath canning –Kills molds, yeasts and some bacteria
Department of Family and Consumer Sciences 8 Temperatures 0 o F –Freezing –Temporarily stops growth of microbes, does not kill
Department of Family and Consumer Sciences 9 How Canning Works Air is driven from the jar or can A vacuum seal is formed Prevents air (with microorganisms) from getting back into food
Department of Family and Consumer Sciences 10 The Effect of Altitude Affects how long food is processed; water boils at lower temperatures as altitude increases For water-bath canning: Add time for higher altitudes For pressure-canning: Add pressure for higher altitudes Tennessee Valley varies from feet
Department of Family and Consumer Sciences 11 Use Mason Jars ½ pint Pint Quart ½ gallon (for high-acid juices only)
Department of Family and Consumer Sciences 12 Use Two-Piece Lids Rings Seals (cannot be reused)
Department of Family and Consumer Sciences 13 Jars to Avoid Old-style jars –Wire bails and zinc lids –Cannot be fitted and sealed Commercial jars –Mayonnaise, peanut butter, etc. –Narrower sealing surface –Less tempered (will break in pressure canners)
Department of Family and Consumer Sciences 14 Raw or Hot Pack Raw-Pack –Pack jars with uncooked product Hot-Pack –Pack jars with cooked product –Maintains better color over time –Removes more air
Department of Family and Consumer Sciences 15 Control Headspace Space between product and lid –¼ inch for jams and jellies –½ inch for fruits and tomatoes –1 to 1 ¼ inch for foods processed in pressure canners Too much space, takes too long to drive out air Too little space, may not seal
Department of Family and Consumer Sciences 16 Filling Jars Fill clean jars with food Remove excess air Wipe rims Apply lids and rings Tighten fingertip tight
Department of Family and Consumer Sciences 17 General Principles Follow tested recipes Do not alter ingredients Use water-bath canner for high acid foods, pickles, jellies Use pressure canner for low acid foods
Department of Family and Consumer Sciences 18 For more information on preserving foods safely, contact Pat Whitaker,Extension Agent Family & Consumer Sciences Rutherford County Developed by Janie Burney, PhD, RD Professor, Family and Consumer Sciences