6 Secrets of Hot Water Bath Canning You Might Not Know

published Jul 3, 2012
We independently select these products—if you buy from one of our links, we may earn a commission. All prices were accurate at the time of publishing.
Post Image
(Image credit: Apartment Therapy)

We’re canning, you’re canning, just about everyone is canning these days. And we think that’s pretty fantastic. But before you fill your kitchen with steaming-hot glass jars and pounds of tomatoes, we have a few insider tips that might just make your next canning session go a lot more smoothly.

(Image credit: Apartment Therapy)

A few weeks ago, I had the extremely happy privilege of attending one of Marisa McClellan‘s canning classes during the tour for her recently released book, Food in Jars. (We featured Marisa here on The Kitchn during June with a series of guest posts on small-batch canning.) She shared several canning tips during this two-hour class that I’d never heard before, and cleared up a few mysteries. Let me tell you, there’s nothing like learning from an expert!

(Image credit: Apartment Therapy)

Fill Jars with the Rings On

But obviously, with the lids off, as in the top image. This keeps the rims clean while you’re filling the jars, and saves you the hassle of wiping them down later.

Use a Measuring Cup When Filling Jars

This just makes the whole process go more quickly and smoothly. If you’re filling pint jars and using a one-cup scoop, you know that two scoops will fill the jar. Easy-peasy. It takes away the guesswork.

Screw Lids down “Fingertip Tight”

Screw the lids down just until you start to feel resistance when you tighten, aka “fingertip tight.” Inevitably, some air bubbles get trapped inside the jars while you’re filling them. If the lids are screwed down too tightly, those air bubbles don’t have a way to escape during the hot water bath and can cause your lids to buckle. Leaving the rings and lids a little loose lets that oxygen escape without incident; the lids will form their seal as the jars cool.

Remove Rings Once Jars Have Sealed

Amazingly, you don’t need the rings once the jars have sealed. The lids are so firmly sealed around the rim of the jar that you can literally lift them into the air by the lid alone! Removing the unnecessary rings frees them up for other canning projects, avoids problems with the rings rusting during storage, and allows you to spot potential problems sooner — if the canned good is starting to ferment and create gas, the lids will pop right off.

The Bounce Test for Gauging Pectin

It’s hard to know how much pectin a fruit contains, and therefore, how much you might need to add to get a jam to set properly. Here’s where the bounce test comes in. Fruits that are high in natural pectin will have a more rigid cell structure and tend to bounce when you drop them onto a table, like blueberries and blackberries. Fruits that are lower in pectin tend to smoosh, like strawberries.

Label Jars with the Batch Number

Not only does this help keep your pantry organized, but if there’s a problem — or unexpected success! — with one jar, you know which other jars you need to check. This is especially important if you’re making multiple batches of the same fruit or vegetable over the course of the summer.

Are you canning this summer? What tips and tricks have you picked up from your canning experiences?

(Image credit: Apartment Therapy)

More Food In Jars

(Images: Emma Christensen)