Are you new to preserving food? Have you heard the terms ‘water bath canning’ and ‘pressure canning’ but aren’t sure what those terms mean?
Allow me to fill the gaps for you if this is something new to you. I’ll be telling you what it is to ‘water bath can', what it is to ‘pressure can' jars, which foods need which type of canning method, why these two methods matter, and how to perform each method of canning.
Here’s what you should understand about water bath canning and pressure canning:
What’s the Point of Canning?
Canning is a method of preserving your food (whether purchased or grown) on your own. People choose to do this to save money and also to be more informed about what’s going into their food, and thereby avoid preservatives that are usually found in store-bought food.
When preserving food, you must heat the food to a point where there’s no risk of the bacteria, botulinum forming. This bacterium causes botulism. The bacteria can form on food and produce a toxin. This toxin can poison the person consuming it.
Though it’s a rare occurrence, the poisoning can cause paralyzes and has a 35-65% death rate if not treated accurately and quickly.
The threat alone is enough to take canning protocol seriously. There are certain foods which don’t have a high enough acid content to stop this bacterium from forming on their own.
When canning those specific foods, they should be pressure canned because a pressure canner can get hotter faster, thereby destroying the breeding ground of bacteria.
Prior to the invention of pressure canners, people only had water bath canning. However, they had to can their food for much longer times to ensure they were safe to consume. Where a pressure canner can heat food to a safe point in only 85 minutes, it could take boiling the same food in a water bath canner, from seven to eleven hours.
In short, be sure you know the acidity of the food you’re canning to ensure you use the right canning process to stop bacteria growth.
Low-acid foods are foods which have a pH level above 4.6. These foods don’t have enough acid to stop bacteria from forming.
Therefore, they should be pressure canned when being preserved. Foods considered low-acid are:
There are some foods (such as milk and squash) not recommended for canning at home. Please consider these warnings seriously when canning your own foods.
When canning, you may find a recipe which mixes low-acid and acidic foods. Even in these cases, the food should still be pressure canned because chances are the pH will still be above 4.6
The only way to change the pH is to add more vinegar, citric acid, or lemon juice which will make the foods more acidic.
To correctly can low-acid foods, they should be processed in a pressure canner where the temperature reaches 240-250° Fahrenheit, and the jars should be processed anywhere from 20-100 minutes. The time and temperature will vary depending upon the item being canned.
Most vegetables require less process time, while most meats require longer processing time. The recipe you follow should give you specifics as to what weight the food should be processed under and the amount of time it should be processed.
Acidic foods are food which has a pH of 4.6 or below. These foods have enough acid within themselves naturally, they don’t require a higher temperature to kill bacteria.
Foods which are considered acidic are:
These foods require a canning time ranging from 5-85 minutes and can be preserved safely in a water bath canner.
Tomatoes are the one exception to the rule. They’re acidic enough to get by with being water bathed in some cases.
It’s a good idea to add extra lemon juice or citric acid to the recipe if you’re going to water bath tomatoes for safety purposes.
However, I still prefer to pressure can my tomatoes because they can be processed much quicker, and I know they’re safe to eat.
Follow the recipe of your choice, but if they suggest water bathing, make sure citric acid or lemon juice is somewhere in the recipe.
If not, I wouldn’t chance it. It’s better to err on the side of caution and pressure can instead.
Water Bath Canning
Many beginners prefer water bath canning because it’s less intimidating. The process is simple as well.
If you’re new to canning, you may not know what it means to water bath can. This method is when you place jars in a canner which has water in it. The water boils and heats the jar to vacuum seal the jar.
To start water bath canning, you must finish the recipe at hand which you’re planning on preserving. Once the food is in sanitized jars, place the jars in a water canner or a large soup pot.
Purchasing a canner is a good idea because it’ll hold more jars at a time, which will speed up the canning process.
When the jars are in the canner, fill it up until the tops of the jars are covered. Turn the heat under the canner on high until the water begins to boil.
Once the water boils, set a timer for the amount the recipe tells you to process them. When the timer is complete, turn off the heat, and use jar grabbers to remove the jars safely.
Be sure to place them on a surface which won’t scorch.
Pressure canning is a similar process to water bath canning, but the equipment you’re working with is much different.
If you’re unfamiliar with what pressure canning is, it’s when you place jars in a large pressure cooker to heat the food to a higher temperature than you can with boiling water.
This process will vacuum seal the jars and sterilize the food simultaneously making it safe to be stored on the shelf, similar to store-bought canned goods, for a more extended period.
Be sure to read the directions of your pressure canner before you get started.
Also, if you have someone around you who has experience pressure canning, ask them for help your first few times if it’d make you more comfortable.
When pressure canning, you’re dealing with a large pressure cooker. If you’ve dealt with a pressure cooker before, you’ll most likely be fine.
If like me (before canning), you haven’t, you might want to call up a friend who has.
With all the safety suggestions out of the way, here’s how you pressure can low-acid foods:
1. Place Jars in Canner
To begin, place the jars in the canner. The jars should have your finished recipe in them, sanitized lids and rings on them, and the jars should’ve been cleaned and sanitized also.
You should be able to fit six jars around the outside edge of the canner and one jar in the center.
2. Add Water
Place the canner on the stove and add three quarts of water to the canner. When the water has been added, place the lid on the canner. Be sure it locks in place.
3. Watch the Pressure
Turn the stove on high. If your canner has a pressure gauge, watch the pressure. You don’t want it to get any higher than halfway.
I prefer the pressure canners which have the rocking mechanism on top. Don’t touch the canner while it’s building up the pressure. You simply wait.
4. Start the Timer
When the gauge on the pressure canner reaches halfway, or the rocking mechanism begins to rock, turn the heat of the stove down to medium.
The idea is to keep the pressure leveled out in the canner. If the rocking mechanism is moving too quickly or the gauge is too high, turn the heat down further.
If the gauge is dropping or the rocking mechanism slows too much, turn the heat up. Begin timing the process according to the recipe as soon as the gauge hits halfway, or the rocking mechanism starts to rock.
5. Remove Jars
When the time is up, turn off the stove. Don’t touch the pressure canner, and don’t remove the lid. It’s under pressure.
Therefore, you must wait until the pressure plunger drops to remove the lid. When the plunger has dropped, carefully remove the lid, and use jar grabbers to remove the jars from the canner.
Place the jars on a surface which won’t scorch under the heat.
It’s my hope you now have a better understanding of what it means to can, and the two processes of canning.
Also, I hope you understand the importance of choosing the proper canning method and why it matters. With this understanding, you should be well on your way to developing your canning skills.