Water-Bath Canning: Never Fear, Botulism is not Near

Picture yourself at the grocery store looking to buy a jar of jam. You notice that, in addition to the jam itself, there’s a lot of water in the jar. Why is that? What purpose does this water serve? It’s actually a form of food preservation called “water-bath canning,” and it might just help your business. 

In this Union Kitchen resource guide, we’ll learn about the process of water-bath canning, the science behind it, and the products that work best for it.

First, things first. What exactly is “water-bath canning?” Water-bath canning is a method of food preservation using boiling water. 

To see exactly how this works, we need to go to the microscope level. Place your typical food under a microscope, and you will see a lot of bacteria. While most of the bacteria found in food is harmless, certain kinds of microbes will damage the food over time. Mentally, picture a rotting piece of produce. Since your food needs to last long enough to sell and be consumed by a customer, you’re not going to want to let your product rot. The boiling portion of the water-bath canning process kills these harmful microbes that thrive on water activity. This not only keeps the food tasting fresh, but it also keeps the consumer safe from disease and other harmful components that would otherwise arise. 

Tomatoes in a Jar Compressed.png

When exactly did people start water-bath canning? 

The short answer is relatively recently. The first group to start canning food was the Napoleonic French army, who used glass bottles to preserve large amounts of food. After the Napoleonic Wars, this practice slowly spread throughout Europe and North America. Nearly a century later, World War I drove up the demand for a method to transport cheap, high-calorie foods to feed soldiers. Once again, canning became the military’s best friend. Following WWI, companies that specialized in canning for soldiers turned their attention to selling to civilians. As technology advanced through the century, various canning methods, including water-bath canning, became increasingly available and prevalent to North Americans and Europeans.  

Steps to Water Bath Canning

Before you get started, you’re going to need some equipment. Make sure to have: 

  • Canning jars with lids 

  • Large pot with a tight-fitting lid

  • Flexible, nonreactive spatula

  • Canning funnel

  • Jar lifter

  • Lid wand 

After cleaning all the equipment in hot soapy water, you’re ready to get started. 

  1. Bring the water in the pot to a simmer. 

  2. Place the jars into the large pot, which should have just enough water to cover the jars. The jars shouldn’t be touching the bottom of the jar, so make sure they’re on a canning rack or a piece of cloth. 

  3. Let the jars sit in the simmering water for at least 10 minutes. 

  4. At the same time, place the jar lids, but not the bands, in a small saucepan and cover it in water. Like the jars, the lids should sit in simmering, but not boiling water for 10 minutes. 

  5. When both of these are done, fill the still hot jars with your recipe to within a half inch of the jar’s rim. It’s recommended that you stir the jar’s contents to release any potential air bubbles. 

  6. Place the lids and bands on the jar. Tighten the lids until you feel resistance, but make sure not to overtighten. Immediately begin to place the jar onto the rack or cloth in the pot. 

  7. Once the rack is filled, lower it into the water again. The water should always be at a rolling boil and should cover the top of the jars by 1 or 2 inches. 

  8. Let the jars sit for the allotted time. 

  9. Afterwards, turn off the heat and let the jars sit for another five minutes. 

  10. Finally, remove the jars and place them on a towel in a dry area, away from any drafts. The jars will need to sit for 12 to 24 hours to properly cool down. 

  11. After the jars cool, make sure that the jar is properly sealed. To check, unscrew the bands and press down on each lids center. If there’s no give, the jar is properly sealed. If you’re able to push down on the lid, the preservation won’t work. You’ll need to either eat it yourself or throw it away. Barring this, your product should now be good for up to a year. 

What products are best for water bath canning?

If you are considering this method of preservation, make sure that you have the right product to do so. Water-bath canning works best with acidic foods. For example, tomatoes and tomato-based products, such as salsa, work well with this method thanks to tomatoes’ acidic nature. Water-bath canning can also work with low acid levels, such as vegetables. Take note, though, that low-acidic produce must first be pickled in a vinegar solution before canning to raise the acidity level.

Hopefully, you’ve found this guide interesting, and you’ve come away with an understanding of the science of water-bath canning. If you decide that this works best for your product, you can find all the necessary equipment, minus the jars and lids, right here at Union Kitchen. For more business resource guides, check out more Union Kitchen’s Resource Guides.