When a poster is troubleshooting a recipe, many times a photo is posted of a canned good whose headspace is much larger than recommended. When headspace is too large, it risks an improper seal, which can lead to food discoloration and spoilage.
Although seepage/siphoning is known to occur, especially with pressure canning, oftentimes the excessive headspace is a result of operator error when measuring. Sometimes a poster may think to measure from a lower portion of a jar, starting under where a metal band is screwed instead of the top rim of a jar.
The following pictures give some visual tips on headspace for a majority of water bath canning recipes that beginners try:
1st Pic: a headspace measuring tool. Each “step” represents 1/4 of an inch. Well worth the purchase for fast and easy measurement of headspace.
2nd: Measuring 1/4 inch headspace. This is often the headspace you need for jams, jellies, and syrups. Note you measure from the rim.
3rd: Measuring 1/2 inch headspace. See that it’s the “2nd step” down. This is often the headspace you need for pickles, relishes and salsas.
4th: a visual guide from Ball. For most Ball mason jars, you can use the grooves to roughly estimate headspace. I reference both the grooves and my measuring tool for each space, using a soup spoon to add or subtract fluid as needed.
Headspace of 1 inch is usually for low acid and pressure canned goods.
Finally, below is an additional link to an article about headspace. Hope these tips are of help! Good luck and happy canning!
https://www.healthycanning.com/the-role-of-headspace-in-home-canning/
by Stardustchaser
3 Comments
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I use a chopstick for bubble popping, but this headspace tool is my favorite. It’s so easy to use and takes the guesswork out of headspace.
You can also find one in the Ball kit along with a jar lifter (IMHO, essential) and a standard funnel (very nice to have).
https://www.ballmasonjars.com/products/products-to-get-you-started/starter-kits-utensils/canning-utensil-set/SAP_1440010809.html
I literally just bought one for a friend that wants to try canning.
This is a great post, thank you!