Home canning allows eco-conscious vegetarians to preserve the bounty of local fruits and veggies that come during the summer and autumn months, which leads to the possibility of eating local throughout the year. Vegetarians who enjoy cooking can take the next step into crafting their own homemade sauces, salsas and chutneys -- and then preserving them for later home use or for gift giving.
High- Versus Low-Acid Foods
Deadly botulism bacteria live on the surface of most fresh vegetables, but the bacteria remain nontoxic if exposed to air. In the airless environment inside a can, however, botulism can flourish unless exposed to temperatures high enough to kill the bacteria. When canning fruits and vegetables, safety should be your top priority. The temperature you need to reach when canning vegetables depends on the acidity of the food. High-acid foods require lower temperatures, reached by simply boiling water. Fruits, jams, jellies, marmalades and pickles are high-acid food. Tomatoes reach the correct pH if you add lemon juice. All other veggies, including beans, are low-acid foods and require a pressure canner to reach safe cooking temperatures. (See References 1, pages 6-8)
Fruit- and vegetable-based foods like jam, tomato sauce and salsa utilize the boiling-water method. Heat the glass jars and the lids to at least 180 degrees Fahrenheit before beginning. Fill the jars according to the recipe instructions, leaving 1/4-inch space at the top for sauces, jams and pickles, and a 1/2-inch space for whole fruits or vegetables. Seal the lid and process the jars in a boiling-water canner with the water level 1 to 2 inches over the tops of the jar. The recipe specifies how long to process the jars. (See References 2, pages 10-12)
Canning beans and vegetables except tomatoes requires a pressure canner, which can reach temperatures above the boiling point. After heating the jars and lids and filling the jars, place the jars in the pressure canner and heat until the steam flows for 10 minutes. Close the vent and wait until the gauge indicates it has reached the pressure the recipe requires, then set the timer for the processing time in the recipe. (See References 2, page 12)
Most vegetarian canning recipes require ingredients you probably already have in your pantry -- sugar, vinegar and spices -- as well as an abundance of fresh fruits and veggies. A few vegetarian favorites may require special supplies. For making jellies and jams, your recipe may call for pectin, an ingredient made from fruit that causes fruit products to form a gel. You can often withhold the pectin but will need to process your cans longer in the boiling-water canner (see References 2, page 28). When pickling foods, use pure granulated, pickling or canning salt to prevent the brine from becoming cloudy (see References 2, page 44).
- U.S. Department of Agriculture: Complete Guide to Home Canning -- Principles of Home Canning
- "Ball Blue Book of Preserving"; 2006
First published in 2000, Dawn Walls-Thumma has served as an editor for "Bartleby" and "Antithesis Common" literary magazines. Walls-Thumma writes about education, gardening and sustainable living. She holds a Bachelor of Arts in psychology and writing from University of Maryland and is a graduate student in humanities at American Public University.
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