Here’s what I tell people when they confess that they are intimidated by boiling water bath canning. If you can make pasta, you can handle a boiling water bath canner. And truly, it’s no harder or more complicated that than! Read through this post for a step-by-step introduction to processing high acid preserves in a water bath.
So, a little disclaimer to start out with. I’m going to detail my particular canning workflow. This might not be exactly how you do it in your kitchen and that’s okay. We all find ways to make it work with the tools, equipment and space that we have. In the end, the most important things are that you get your jars hot, that you fill them with a freshly made, hot product to the proper headspace, you use new lids, and that you process them for the amount of time prescribed by your recipe. There’s a good deal of flexibility in the rest of the details.
As I mentioned in the first post in this series, any pot can be your canning pot as long as it’s tall enough to hold a rack and your jars, and that it allows the jars to be fully submerged in the water. I like this one (thought it’s best for pints and smaller, it’s a little too short for quarts) but the best pot to use is the one already in your kitchen. If you don’t already have a pot that’s large enough to serve as a canner, I recommend opting for a durable stainless steel pot rather than a traditional enamel canner, as it will be more durable and versatile.
Once you’ve picked out your pot, position a rack in the bottom. I have a silicone trivet pictured here, but any round rack, or collection of old canning jar rings. Once you have a rack in your pot, place the jars you’re using on top.
Then, fill up the jars and pot with water. I like to use the hottest tap water available, as it speeds up the boiling process a bit to start.
It’s a little hard to see in this picture, but at this point, I only fill the pot enough to just barely cover the tallest jar I’m using. This should be more than enough water for the processing stage, because the jars are currently empty.
Once you remove the hot jars, fill them with your product, close them, and lower those filled jars in the pot, they will displace enough water that they will be sufficiently covered. Sometimes, you’ll even need to remove a little water from the pot to prevent overflow. If this becomes necessary, use something heatproof, like a Pyrex measuring cup so that you don’t burn yourself.
It is always a good idea to pour a generous glug of white vinegar into your canning pot before you start heating it. This will prevent any minerals present in your water from depositing on your canning pot or jars. I don’t live in a place with particularly hard water, but I still do this because it keeps my pot in good shape and makes it easier to clean. If you’re someone who likes more precise measurements, use between 1/4 and 1/2 cup.
Now the pot is ready to go on the stove an come to a boil. I do all of this before I ever apply heat to my preserves. That way, the canning pot has a head start on my product and the jars will be nice and hot when I’m ready to use them.
A note about lids
It used to be that you’d need an additional small pot running next to your canner, in which to warm your new lids before using. Back in 2014, Ball Canning announced that it’s no longer necessary to simmer lids prior to canning, as the plastisol sealant doesn’t require softening. Instead, they just need to be washed in warm, soapy water before applying them to filled jars. This change applies to all Ball, Kerr, Golden Harvest, and Bernardin lids. More information about this can be found here.
If you are using lids from a different manufacturer, make sure to read through the package instructions to determine whether or not they need to be warmed before use.
When the product is ready to go into the jars, I slide the canning pot off the heat and pull out the jars with a handy jar lifter. Just a note: These jars are hot, but not sterilized, because I turn the heat down to a simmer as soon as the pot boils. Jars do not need to be sterilized prior to filling if your processing step is ten minutes or longer.
However, if your recipe calls for a processing time that is shorter than ten minutes (very few modern recipes use this shorter processing time), you need to actively boil your jars for at least ten minutes before filled, to ensure you have sterilized jars.
Now you fill up your jars, leaving the amount of headspace required by your recipe. If the recipe doesn’t tell you how much headspace to leave, use 1/2 inch.
Before applying the lids and rings, wipe the rims with a damp paper towel or clean kitchen cloth. I use the hot water from the canning pot as my dampening water, as the heat helps remove any stubborn sticky spots. If your product is super sticky, a little white vinegar on the cleaning cloth will help.
Then, center a lid on each jar and secure it with a ring. Tighten the ring just until it meets resistance. The term for this level of tightening is called “finger tip tight” meaning that you only tighten as much as you can with the tips of your fingers. This allows the oxygen to vent, which is what produces the airtight seal once the jars cool.
Once all the jars have lids and rings, lower them into your canning pot. Make sure the jars are fully submerged and are covered with about an inch of water (you need that much to ensure that they won’t become exposed during boiling). Turn the burner to high. When the pot returns to a boil, set a a timer to the prescribed amount of processing time.
You do want to maintain an active boil throughout the processing of the jars, but make sure you control your boil. If the pot is madly rolling, the chances that you will burn yourself increase. Turn it down a little, to minimize splashing and injury. I like to use one of these spill stopper lids on my canning pot rather than the original lid, as it also helps manage the mess of the boil.
When time is up, turn off the heat. Remove the lid and let the jars stand in the water for five minutes. This allows them to cool more gradually and prevents the product loss that sometimes occurs if you take the jars out too quickly. It can also improve the quality of the seal.
Once that rest period is over, lift your jars out of the pot and place them on a folded kitchen towel or wooden cutting board to cool. You don’t want to set them onto surfaces made from stone, metal or tile, as their cooler temperatures can cause the jars to break.
Once the jars are out of the canner, leave them alone and let them cool. Best practice is to leave them alone for a full 24 hours, but if you can’t manage that, try to wait until they are completely cool to the touch. As the jars cool, you should hear the lids making a series of popping and pinging sounds.
These noises are indications that the jars are sealing as they should. However, don’t freak out if you don’t hear those noises. Jars sometimes seal slowly and quietly. Once the jars are completely cool, remove the rings and test the seals by holding onto the edges of the lids and lifting up an inch or two. If the lids hold fast, the seals are good.
Sealed jars should be stored in a cool, dark place without the rings. If the jars are at all sticky after processing, make sure to wash them before you put them away. Any sticky residue can attracts ants and other pests, so make sure your jars are squeaky clean.