What To Do When You Don’t Have Enough Jars To Fill a Water Bath Canner  

So you’re processing a small load when you realize you don’t have enough jars to fill your water bath canner. What do you do? 

The short answer is … no problem! Your water bath canner doesn’t need to be full. 

There is an important point to be aware of, however, so let’s talk about that.

Good News: There Is No Minimum Jar Count for Water Bath Canning

In case you’re new to hot water bath canning, here’s a quick overview of how it works:

You submerge jars of food in a water bath canner, which is basically a large pot with a rack in it. 

Boiling the water around the jars for a specified time vacuum seals the jars. The heat also helps to kill pathogens, although this only works for high-acid foods. 

Foods with a pH of 4.7 or higher (more alkaline foods like meat and some vegetables) must be pressure canned. 

Pressure canning is a different process involving pressure and steam to raise the temperature much higher than possible by simply boiling water in an open pot.

While the water bath canner itself needs to be a minimum size to ensure the jars within are completely submerged, there are no recommendations for a minimum jar load for water bath canner. 

The Only Concern if You Do Not Have Enough Jars for a Full Load

If a jar is tilted before it has a chance to fully seal (usually 12-24 hours after being removed from the canner), food particles may get caught between the lid and jar rim, and the seal just won’t work. 

This is an issue when processing partial loads of jars. When jars are closely nestled against each other, they naturally hold each other up. With a partial load, you don’t have this built-in “support” to keep your jars upright.

It’s also harder to lift jars straight up when removing them from the canner. Again, the lack of support on either side of jar makes it easy for the jar to tilt and fall in the water as you try to pull it out of the canner.

There’s also more of a possibility of breakage when you use fewer jars since a less full water bath canner means more room for them to move around. 

If you’re canning a small load of jars, use a smaller pot when possible and don’t can with jars that are less than half full of food, as they may float off of the rack. 

Alternatively, you can fill the extra space with jars of water. Canned water is sterile and great to have on hand for emergencies!

Finally, it’s smart to ensure your canning jars are in pristine condition to avoid breakage. While this is always important, it’s even more crucial when using only a couple of jars that are more likely to fall against each other. 

To ensure that your jars are strong, take a few precautions:

• Don’t weaken your canning jars inadvertently. If you frequently scrape inside with metal utensils, use them daily for drinking and leftovers, or store them in extreme temperatures, you could be causing weak points in the glass.
• You also want to avoid sudden temperature changes—for example, putting hot jars on cold countertops. 
• Don’t overtighten your jars.

The Source of Misconception About Having Enough Jars to Fill Your Canner

Alarm bells may be ringing in your head right now, as you think “Hmmm, I’m pretty sure I read that there actually is a minimum jar load for canning.” 

You’re right, but this only applies to pressure canning, which is different than water bath canning. 

There are official recommendations for the number of jars that should be used when pressure canning. 

Ball Canning Company issued a statement in 2016 recommending a minimum of 2 quart-size or 4 pint-size jars (or a configuration thereof that equals a 2-quart volume) to ensure that the pressure and temperature needed to kill pathogens is achieved.

Final Thoughts: How Full Should A Water Bath Canner Be?

Hopefully this clears up any misconceptions you may have regarding the minimum number of jars needed to fill a water bath canner. 

If you’re trying to get your canning finished and end up with not enough jars to fill your water bath canner, don’t worry. As long as your food doesn’t require pressure canning, in which there is a minimum jar count per load, feel free to finish up with only a couple jars.