Now that I’ve shown you how to use a water bath canner, it’s time to move on, and talk about using a pressure canner. If you need to learn some canning basics, such as how to sterilize jars, you can read my first diary in this series, Part 1, Using A Water Bath Canner. Part 2 covered canning things like pie fillings, fruit sauces and butters, and juice. In Part 3, I covered the basics of making jellies, jams, and preserves. See Noddy’s diary on small batch canning if you only need to can small quantities at a time.
A pressure canner is the only way to safely can low-acid foods at home--that is, foods with a pH of 4.6 or higher. Low-acid foods include most vegetables, beans, and meats. A pressure canner reaches a temperature of 240 degrees--hot enough to kill the microorganisms that cause botulism. You can also can fruits in a pressure canner, if you like. The processing time is generally very short. Jams jellies, and preserves, however, can’t be pressure canned, since the intense heat will cause the pectin in the jelly to break down.
Canning your own vegetables can save you a lot of money--even if you don’t have a garden, you can take advantage of sales, and buy the produce in bulk when it’s cheap. Be sure to check out your local farmer’s markets and CSA’s--you can often get better prices than at the grocery store. I sometimes buy 50 pound bags of potatoes and can them--around here, you can get a bag that size for around $10 or $12, and you’ll get about 25 quarts out of it. That comes to about 40 or 50 cents a quart--less than half the cost of store bought canned potatoes. We use them in casseroles, to add to soup, or to make scalloped potatoes. In addition, canned foods are good to have around in case of emergencies--they won’t spoil if the power goes out.
There are generally two types of pressure canners available on the market--weighted gauge canners, and dial gauge canners. The type you use is a matter of personal preference and budget. You can pick up a weighted gauge canner for around $75. A high quality dial gauge canner can cost upward of $200 or more--but they are well worth the investment, since they will often last a lifetime. Most of the less expensive canners I’ve seen have a gasket that will need to be changed every few years--if you notice that it has any little cracks or chips, or it starts to feel gummy, replace it. Oftentimes, you can find pressure canners at yard sales--some people try out canning, but don’t like it--so they end up selling their stuff cheap. If you buy a used pressure canner, you’ll want to check and make sure all the parts are there before you purchase it.
Below is a picture detailing the parts of a pressure canner:
Depending upon your altitude, you’ll need to make adjustments to the amount of pressure you use. Be sure to read the documentation that came with your canner to determine the right way to set the pressure, but in general, if you are using a weighted gauge canner, you’ll notice that that the little pressure regulator (the parts that sits on top of the petcock or stem port) came with two weights. If your altitude is 1,000 feet or less above sea level, use one weight, to set the canner at 10 pounds of pressure. If you are at an altitude of 1,001 feet or more, use two of the weights to set the canner at 15 pounds of pressure. If you’re using a dial gauge canner, you just heat the canner until the gauge reads the proper level of pressure for your altitude. Below is a chart detailing the correct level of pressure to use based upon your altitude for dial gauge canners:
Altitude Pressure Reading
0-2,000 ft 11
2,001-4,000 ft. 12
4,001-6,000 ft. 13
6,001-8,000 ft. 14
Above 8,000 ft. 15
Here are the basic steps in using a pressure canner:
The first step is exactly the same things you would do if you were using a water bath canner--clean and sanitize your work area, start sterilizing the jars, and get the lids and rings ready by letting them soak in hot water.
Put the rack on the bottom of the pressure canner, and pour about 3 inches of water in the bottom. Arrange your packed jars in the canner--make sure they don’t touch so water can circulate freely around the jars.
Then, put the lid on the canner. If you look closely, you might notice a little set of arrows on the lid and on one of the handles of the canner. Line those up, and then slide the lid into place. If you are right-handed, put the side with the arrows on the left, and vice versa if you are left-handed. This will make it a little easier for you to get the lid on and off.
Start heating the canner on high heat. Soon steam will start coming out of the vent port or petcock. Let it vent steam for about ten minutes.
Next, put the weighted gauge on the steam vent, or close the petcock. Soon, if you are using a weighted gauge canner, you’ll hear it start making a chug, chug ,chug sound and the weighted gauge will start rocking back and forth. If it’s rocking back and forth really fast, turn the heat down a little. If you’re using a dial gauge canner, watch for the dial to reach the proper level of pressure for your altitude. Adjust the heat so that the pressure reading is at, or slightly above the proper pressure level.
Now, start timing it, according to the processing time for your recipe. Once the processing time is done, turn the heat off, and let the canner cool. If you’re using a weighted gauge canner, wait at least 5 minutes after the gauge has stopped rocking back and forth and no more steam escapes before you remove it. If using a dial gauge canner, wait for the pressure reading to each zero. Then open the petcock. Let the canner cool for at least 10 minutes before you remove the lid. Hold the lid in front of your face when you open the canner to keep from getting a steam burn.
Then just take the jars out of the canner using a jar lifter, and let them cool. It’s best to cover them with a towel to protect them from drafts. Within a few minutes, you’ll hear the jars start to “pop” as they seal. Once they are completely cool, check them to make sure they sealed properly. If some of them didn’t seal, put those jars in the fridge and use them right away, or take the food out of the jars and put it in the freezer. It’s not a good idea to try to reprocess pressure canned food.
Now that we’ve covered the basic steps in using a pressure canner, I can talk to you about how to prepare some commonly pressure canned vegetables and tomatoes. Some vegetables need to be blanched a little before you can them--it helps to preserve their color and texture. You can use the same water you blanched them in to pack the jars--this helps to preserve some of their nutrients. When packing the jars, it’s important not to pack them too tight--if the jar is packed too tightly, it will be very hard to get all the air bubbles out when you stir it. Some foods swell up a bit as they cook--a too tightly packed jar can sometimes burst in the canner. Also, jars that are too tightly packed might not reach an internal temperature of 240 degrees, which is necessary to kill the spores that cause botulism. It’s better to pack them a little too loose than it is to pack them too tightly.
Whether or not you add salt to each jar is up to you--if you like, use about ¼ tsp. per quart jar. Note that iodized salt can cause some canned products to have an off-taste, so make sure you use plain, non-iodized salt.
Below is a chart detailing the amount of produce you’ll need to make a canner load of 7 quarts. If you are canning for just one or two people, you might want to pack your produce in pint jars instead.
9 pints 7 quarts
Green Beans 9 lbs. 14 lbs.
Carrots 11 lbs. 18 lbs.
Corn 32 lbs. 20 lbs.
Greens 28 lbs. 18 lbs.
Shelled peas 9 lbs. 14 lbs.
Potatoes 8 lbs. 14 lbs.
Tomatoes 14 lbs. 20 lbs.
Green Beans Start a large kettle of water boiling--this is what you will use to pack the jars. Wash, string, and break up the beans. If they have any little black spots on them, you can cut these parts out, or discard them. I don’t blanch green beans before I pack them, but you can if you like by dipping them in some boiling water for 1 minute. Fill the jars--you can pack beans kind of tight, if you like. Leave 1 inch of headspace in the jar. Pour in just enough water to cover the beans, then stir them to remove any air bubbles. Wipe the rims of the jars clean, and put on the lid and rings. Process according to the chart below. Yellow wax beans and lima beans can be canned in the same manner as green beans.
Carrots Get some water boiling to use to pack the jars. Peel the carrots by scraping them with a sharp knife and cut off the tops and ends. Wash them, then cut them up into ¼ inch slices. Carrots turn out best if you hot pack them--cook them in some water for about 5 minutes. Pack the jars, leaving about 1 inch of headspace. Pour the water you used to cook the carrots into the water you are going to use to pack them with, and bring the water back to a boil. Pour enough water in each jar to cover the carrots, then stir them to remove any air bubbles. Clean the rims of the jars and put on the lids and rings. Process according to the chart below.
Corn Note that the amount of corn I specified for this recipe refers to the weight of the corn with the husks. This recipe is for whole kernel corn. Get some water boiling to use to pack the jars. Shuck the corn, and remove the silk. Wash the ears to remove the rest of the silk. Using a sharp knife, cut the corn off the ears-you don’t need to scrape the corncob, just cut about three-fourths of the way into the kernels. In a large kettle, cook the corn in about 2 quarts of water over high heat for 5 minutes. Remove the corn by pouring it through a colander, reserving the liquid. Add the water you used to cook the corn to the water you are using to pack the jars, and bring to a boil. Pack the jars loosely, leaving 1 inch of headspace. Pour enough water in each jar to cover the corn. Wipe the rims of the jars clean, and put on the lids and rings. Process according to the char below.
Greens This includes greens like spinach, kale, mustard, and turnip greens. Start a pot of water to use to pack the jars. Cut the root ends off the greens, and pick out any bad looking leaves. Wash them thoroughly to remove any dirt. If you like, chop them up. Blanch the greens by cooking them, a small amount at a time, in the water you are going to use to pack the jars--each load only needs to cook for about 1 minute. Pack the greens in the jars, leaving 1 inch of headspace. Pour in enough water to just cover the greens, and stir them to remove any air bubbles. Wipe the rims of the jars, and put on the lids and rings. Process according to the chart below.
Shelled Peas Get a pot of water boiling to use to pack the jars. Shell the peas, then wash them thoroughly. Pack the peas into the jars, leaving 1 inch of headspace. Pour enough boiling water into each jar to just cover the peas. Stir them to remove any air bubbles. Wipe the rims of the jars, and put on the lids and rings. Process according to the chart below.
Potatoes Start a large pot of water boiling to use to blanch the potatoes and pack the jars. Peel the potatoes, and cut them into either 1 inch cubes, or simply slice them. If you slice them, make sure the pieces are small enough to easily fit in the jar. Wash the potatoes thoroughly, then soak them in a large bowl of cold water to which some fruit fresh has been added--potatoes tend to turn brown when you can them. Drain the potatoes, then blanch them, a small amount at a time, by cooking them in the boiling water for 2 minutes. Remove the potatoes from the water, and pack the jars, leaving 1 inch of headspace. Pour enough water in each jar to just cover the potatoes. Stir them to remove any air bubbles. Wipe the rims of the jars, and put on the lids and rings. Process according to the chart below.
Tomatoes I personally prefer to use the pressure canner for tomatoes--you don’t have to add lemon juice or vinegar to them in order to be sure they will be safe. Note that this recipe calls for paste-type tomatoes, such as Romas--if you are using one of the juicier varieties, you will need to cook the tomatoes down before you pack them, so you won’t get as many jars. First, get a pot of water boiling to use to pack the jars.
Get another pot of water going to use to skin the tomatoes. Dip the tomatoes, a few at a time, in the boiling water until the skin starts to crack. Remove the tomatoes, and put them in a bowl of ice water. Remove the skins, and cut out the tough stem ends of the tomatoes. Quarter them up, and pack them in the jars fairly tight, so the juice helps to fill up the spaces between the tomatoes. Leave ½ inch of headspace. Pour just enough boiling water over them to cover them. Stir them to remove any air bubbles. Wipe the rims of the jars, and put on the lids and rings. Process according to the chart below.
Processing Times
Product Pints Quarts
Green beans 20 min. 25 min.
Carrots 25 min. 30 min.
Corn 55 min. 85 min.
Greens 70 min. 90 min.
Shelled peas 30 min. 40 min.
Potatoes 35 min. 40 min.
Tomatoes 25 min. 25 min.
When reheating low-acid foods, you should always bring them to a boil, and let them cook for at last 10 minutes. If you are combining them with other foods in the dish you are preparing, the time the entire dish cooks can count toward this heating time.
That’s all there is to canning vegetables in a pressure canner--nothing to it, right? There are plenty of good books and online resources that will show you how to can many types of vegetables, and even fruit, in a pressure canner. In Part 5, I’ll show you how to can meats, broth, and soup stock.