Canning 101

by Sara on October 3, 2009

The first time I decided to try my hand at home canning, I was terrified. If you read any “how-to” instructions on canning, they sound so scary! In reality, it’s really not difficult to can, but there are a few important steps to take so that you do not poison your family and friends.

1. Always use new lids. I do keep my old lids and use them for freezer jam, but if you’re worried things might get mixed up, only use lids that are fresh out of the box. Lids are pretty inexpensive, so why chance a bad seal – you could lose all of your hard work, or get sick. Neither sounds very appealing to me.

2. Only use jars specific to canning (mason jars). These jars are designed to withstand the high temperatures necessary for canning.

3. Always wash jars and lids with hot soapy water, then sterilize the jars by placing them right-side up in a canner or deep stockpot. Fill with hot water to 1 inch above the top of the jars and bring to a boil; continue to boil for 10 minutes. (If you’re above 1,000 feet in elevation, you’ll need to add an additional minute to the boiling time for each additional 1,000 feet in elevation.) Remove jars one at a time from the hot water to use in canning. Save the water – you can use this for the water bath.

4. The “rules” differ between high acid foods (tomatoes, salsa, fruit, jams) and low acid foods. Higher acid foods are able to block the growth of the bacteria that causes botulism, and kill it when heated to high temperatures. Thus, high acid foods tend to be the choice of novice canners. Low acid foods (meat, vegetables, seafood, milk, poultry) require a pressure canner, as the botulinum bacteria is destroyed at a temperature of about 240-250*F. The time needed to process the canned goods varies based on what is being canned, so follow the recipe! Canning is not the time to improvise.

5. When filling the jars, always leave 1/2 inch of headspace (unless the recipe calls for more) and wipe the top of the jar clean before covering with the lid and ring band. Place the jars in the water bath one at a time with a jar lifter (okay, I just use a tongs). Make sure there is at least one inch of water covering the top of the jars and process the jars in boiling water for the length of time specified in the recipe. After processing, turn off the heat and wait a few minutes, then remove the jars from the water bath. Cool jars on a wire rack or towel to cool; allow 12-24 hours to seal. For any jars that don’t seal, you can replace the lids and reprocess, or put the jars in the fridge.

These are general instructions for canning. Remember that instructions given in a recipe will trump what I’ve written here, as the rules do change a bit based on what you’re canning. In general, beginning with tomatoes, fruit or fruit products, and salsa are fairly foolproof due to their higher acid content (though some tomatoes are not as acidic as others). My first time around, I definitely walked the line of being too careful, but I was giving away a spiced fruit preserve around the holidays, and I certainly didn’t want my gift to hurt anyone!

Tomorrow I will post my adventures in canning salsa!

{ 1 comment… read it below or add one }

Ira Mann October 13, 2009 at 12:07 pm

I have recently started learning how to can. I need all the help I can. Thanks for all your wonderful information. You, have helped me so much. Thanks again.

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