Never Lay canning Jars on Their Side

A question came in from Jake, who’s gearing up for his first attempt at canning tomato sauce. He asked if it’s okay to lay jars on their side in the water bath since his pot isn’t tall enough to cover them with water.

This is a great question, and I’m glad he asked before diving in. Here’s the short answer: no, you should never lay jars on their side when canning. Here is my video answer explaining what happens in your jar and why you should not turn it over when processing.

Why Jars Must Stay Upright

Canning jars are designed to vent during processing. As the contents heat up, they expand and push air out through the lid. This is why you only tighten the screw bands fingertight—to allow that venting process to happen.

If a jar is on its side:

• The contents (in this case, tomato sauce) can leak out during processing.
• You’ll end up with a mess in your pot.
• It will likely compromise the seal, making your canned goods unsafe to store.
• Even if your jars do seal, the seal is not strong and may break in storage.

The Importance of Proper Water Coverage

For water bath canning, jars need to be fully submerged with at least 1–2 inches of water covering the tops. If your pot isn’t tall enough, don’t lay your jars over. Make another plan.

Any pot will do, but it must be deep enough. If you have a deep pot in your kitchen and some sort of rack for the bottom, you’re good to go!  

You can use a cake rack, a rack from a roasting pan or some other sort of rack. It just needs to set on the bottom of the canner and keep the jars steady and off the bottom.

• Do a search on Amazon and you’ll find many options.   Be sure and look at the measurements of your pot so you know what you find will fit.
• Here is a small 8 inch diameter that might fit a stock pot.  
• This is a nice little rack also designed for use in a stock pot.

I’ve got several ideas for canning rack replacements on this post.

Tomatoes: Water Bath or Pressure Canning

Tomatoes are unique because you can process them using either a water bath canner or a pressure canner. Both methods are safe as long as you follow the proper guidelines.

Here is a list of tomato canning recipes here on simply canning. Some water bath, some pressure.