When just starting out in the food preserving world, you might be wondering what the difference is between water bath canning vs pressure canning. Read on to find out all you need to know about these different canning methods.
If you are just looking for a quick answer, here it is. Water bath canning is used to can high acidic foods while pressure canning is used to can low acidic foods. But what does that mean and how do you know which specific foods are high acidic and low acidic?
Really, knowing what piece of equipment to use and how to use it just comes down to getting into the kitchen and doing it. Sure, you can read all the things but home canning is something you should really be doing hands on. Now, yes, it is important for you to learn about the methods of canning first, which is hopefully why you are here. But when you are done reading, I want you to get into the kitchen and starting doing your choice of food preservation method!
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Water bath Canning vs Pressure Canning
Consulting canning books or the owner’s manual to a pressure canner will tell you which foods are high acid foods or low acid foods. Eventually, with enough practice, you will just know though. Typically, meats and vegetables are done in a pressure canner while fruits, pickles, and salsa/tomato foods are done in a water bath canner. However, there are some rules you need to know before throwing tomatoes into some jars and preserving them with the water bath method.
Water Bath Canning
Water bath canning is boiling jars of food on a rack in a large pot. This is the home food preservation method most beginners choose to start with because it is less intimidating and is very low cost as most people have most of the canning supplies already. Water bath canning uses boiling water to kill any harmful bacteria and uses the hot water to make airtight seals.
For water-bath canning, place a rack in the bottom of the pot. Fill canning jars with food, place lids and bands on, and submerge the jars into the big pot. The amount of water depends on the jar size. Once the processing time is up, take a jar lifter and remove jars. As the jars cool, a vacuum seal is formed.
High-acid foods are used for a boiling water bath canner. High acid foods are foods such as:
- Apples and apple sauce
- Jams and jellies
- Pie fillings
- Pickled vegetables
All these foods have a ph level of 4.6 or lower or they have enough acid added to the jars with lemon juice or vinegar or some kind of acidic fruit juices that it changes the acid level in them to make them safe for water bath canning.
The pressure canning method is used when a water bath canner just won’t get to a high enough temperature. Low acid foods need a temperature of 240 degrees F to kill any bad bacteria or to prevent botulism spores.
This is the method of canning that makes people nervous. A pressure canner is a heavy-duty piece of equipment that creates pressure to get the airtight seal on the jars. The first thing you should know when talking about pressure canning is that this is not pressure cooking, like with a pressure cooker such as an instant pot. While they are similar ideas, it is a different thing we are working with.
There are different kinds of pressure canners available.
A weighted gauge pressure canner, such as the All American, which self-regulates. As long as you can hear the “jiggle” of the weighted gauge, you can listen to hear if the pressure is correct.
A dial gauge pressure canner has more options for the weight, which is great for high altitude canners. However, the pressure gauge must be constantly watched. Once the pressure is where you want it, place a pressure regulator on top of the vent pipe. The pressure inside the canner will then stay unless the burner is turned up or down.
How to Pressure Can
For pressure canning, the process is a bit different whether you are raw packing or hot packing the food.
However, basically, it involves placing a rack into the bottom of the pressure canner, placing 2 inches of water in the canner, putting the pint jars or quart jars in, locking the canner lid into place with some screw clamps and then waiting for the high pressure to build up inside that it forces steam out of the steam vent. When that happens, allow steam to escape for 10 minutes and then place a weighted gauge on the steam vent. Depending on the canning recipe and whether or not you are canning at high altitudes, will determine the pounds of pressure being used. The process time does not start right away but once the pressure gets brought up to what you need, a timer will be set for a specific amount of time to begin the canning process.
Low-acid foods are foods used for pressure canning. These are foods such as:
- Red meats
All these foods have a pH level of 4.6 or above which need a higher temperature of 240 degrees F to kill clostridium botulinum.
Canning can seem a bit overwhelming when first beginning. There are great canning resources available. Try purchasing the following to get you started on your canning journey:
- The Ball Book of Canning and Preserving
- The Complete Guide to Pressure Canning
- The Beginners Water bath Canning Recipe Book