Canning FAQs


As you can imagine, we get a lot of the same questions. In order to maintain our sanity, we’ve developed a list of Frequently Asked Questions, below, that you may find useful.

Please note: canning is the process of preserving food for stable, room temperature, shelf storage. It is more in line with chemistry than it is with cooking. The place to be creative and make up new recipes is when you eat your canned goods, not for the recipe for canning them.

We adhere to current USDA safety guidelines. We cannot condone recipes or methods or equipment that go contrary to these guidelines. European recipes and equipment are often not USDA approved. They may or may not be safe, but we can’t give our blessing to them. See below for the site with USDA guidelines.

Many people try to challenge us with all sorts of scenarios that don’t fit into modern canning safety guidelines and then say, “and it never killed anyone.” And that may be true. What we like to say is that we use our seat belt (safe canning practices) every time we drive (can food). Often you don’t really need the seat belt, but it is extremely important for those times when you do need it. (Thank you to Amy Pennington for the seat belt/canning analogy!)

Where do I find canning classes in my area?

Places to look for canning classes are kitchen stores; some grocery stores (the natural ones like Whole Foods or local co-ops often have them); University Extension programs; garden stores; farms; cooking schools; community centers; libraries. Also, it would be worthwhile to do a Google search for “Canning Classes in [Your City, State]”.

What book(s) do you recommend for a new canner?

There are so many books out there that we couldn’t list them all. And more and more are coming out each day. If you are new or newish to canning, or just want an all-around good canning book, we recommend Ball Complete Book of Home Preserving or The All New Ball Book Of Canning And Preserving. This is the fundamental guide to water bath and pressure canning. It is inexpensive and easy to read and has recipes for all of the basic canned items. From there you can start to look at other books on the bookstore or library shelves and get a sense as to what books meet your needs.

We also highly recommend the National Center on Home Food Preservation website. This is the site that reflects all of the USDA-approved guidelines, recommendations, equipment descriptions, and recipes. We use their Search function (at the bottom of the page) several times a day to answer questions from our readers.

We do not recommend that you get your advice or canning recipes from random blogs. Many bloggers don’t understand the safety issues of canning and unwittingly post unsafe recipes. Go to sites in which the information is clearly coming from experienced and safe canners.

I want to use a recipe for jam that contains pectin but I don’t want to use pectin. Is that OK?

In order for a fruit to “set” (i.e., gel) it is important to cook the jam until the natural pectin of the fruit comes out and combines with the sugar in the recipe, or to add pectin as required by the recipe. There are many, many recipes out there that do one or the other. If you are a new or relatively inexperienced canner and you do not want to use pectin, we recommend that you find a recipe for a jam that does not include pectin. There are many, many out there. The Ball Blue Book is a very good place to start. There are some recipes in which you must use pectin–the low-sugar or no-sugar or sugar alternative recipes: these recipes must be canned with the pectin called for (usually called “low or no sugar pectin).

I have [X] pounds of [fruit/vegetable], what should I can with it?

This is part of the fun of canning–you get to decide what to do with your harvest! We can’t really recommend recipes for you because you are the only one who knows what you like. Also, we are a collective of canners–we don’t have any one recommendation for any one fruit or vegetable. One place you can start looking for recipes is our list of Recipes.

What’s CAA’s favorite recipe for [type of recipe]?

See above answer

Will you take a look at [recipe or website] and tell me if this recipe is safe to can? Variation: Will you look at this recipe and tell me if it’s OK to make [x] changes”? Variation: Where can I go to find out if a recipe is safe to can?

No, we are volunteers and we don’t have the time to do this (unfortunately). If you question whether or not a recipe is safe, then please find a different recipe. Or, you can do a Search on the National Center For Home Food Preservation site to see if that recipe adheres to canning safety. Random cooking (not canning) recipes aren’t designed to be canned. We recommend that you not try to can cooking recipes unless you are a master preserver or are highly experienced and can properly assess the safety of a particular recipe.

Is it safe to can [cooking recipe]?

It may or may not be. If you are a new canner or if you do not have the experience to judge whether or not a recipe is safe to can, then please do not can it. Canning is about preserving food, it is not about being creative in the kitchen. So, if you have a recipe for something that is not a specifically canning recipe, then do not can it. Find a recipe that is specifically for canning. Again, the National Center for Home Food Preservation site has great and safe recipes as does our site.

My Grandma used to can her spaghetti sauce (or chili or soup or whatever) and never killed anyone with it. Do you think it’s OK for me to can it?

See above question and answer. The answer is: maybe or maybe not. If you are not experienced enough to verify that it is safe to can a particular recipe, then please don’t can it. Remember: canning is chemistry–it’s not cooking.

What jars/lids do you recommend?

We can only recommend the jars that have the 2 piece lids, like Ball, Kerr, or Leifheit to name the major brands. They are the only type of jars recommended by the USDA. No other jars or lids (including the Tattler lids) are approved by the USDA for canning in the US. Other types of jars with the one-piece lids are not approved and are tricky to use. Weck jars are pretty and are used a lot in Europe, but they are tricky to get a good seal with unless you are an experienced canner. The old fashioned “bail and wire” jars that have the glass lid that comes down over a rubber seal are pretty but are not safe. These jars are best for storing dry grains or for decorative purposes.

What about concerns over Bisphenol A (BPA) in canning lids?

We are concerned about BPA just as much as anyone. But, to be honest, there isn’t a lot of research out (yet) about the safety of canning lids in relation to BPA. Therefore, we don’t know how much BPA gets into canned goods. BPA is only found on the small part of the lid that hovers over the food. If the jars are stored correctly (upright in a cool, dark space), no food should be touching the lids, therefore avoiding contact between canned foods and canning lids. How much BPA, if any, gets into the food during the processing time is currently unknown.

What do you think of the plastic Tattler lids?

They are not approved by the USDA and we have had reports from canners that these lids have a problem of failing a few months into the storage process. We don’t use them.

Can I reuse canning jars/lids/rings? Also, is it safe to get canning jars at garage sales?

You can reuse jars–but be sure to check them carefully for any chips or cracks that could compromise the seal before you use them. And you can re-use the rings that hold on the lids–be sure to check them for rust or any other damage. But, you cannot reuse the lids. The lids have a one-time-only use. Technically, the sealing compound on the lids is used up after 1 use. You may or may not have the good fortune to get a lid to seal properly for more than 1 use, but we cannot condone this practice. And yes, it is fine to get canning jars at garage sales–just follow the safety check procedures above.

My Grandma/People in Europe use the “Flip and Seal” method and seem to be OK. Do you recommend the Flip and Seal method as an alternative to water bath canning?

No, we don’t. The flip and seal method, which is popular in Europe, just seals the jars. It doesn’t bring everything up to temperature and ensure that you’re killing off the bad bacteria inside the jar. It is not a USDA-recommended preserving method. That said, we do know commercial canners who use this method for highly acidic things, like jam. The key to the flip and seal method is that the jar contents need to be at an appropriate acid level (as measured by a pH meter) and super hot at the time of flipping. One of the members of our group, Kathy Casey, is a master preserver and she uses the flip and seal method in conjunction with a pH meter (see below for more on pH meters). But, it’s not a method to be used by newbies at home.

Also, if you do insist on using the flip and seal method, it is only recommended for jams and jellies–no other types of canned goods.

What about all of the other types of canning methods including Oven Canning, Open Kettle Canning, etc.? Are they safe?

The USDA has determined that these canning methods are prone to so much environmental variation and user error that they are not recommended. Therefore, we do not recommend them, either.

My Grandma used to water-bath can tomatoes without lemon juice and she never killed anyone. Why should I add lemon juice now?

Tomatoes are technically a fruit. Therefore, they are more acid than vegetables. But, over the years, the produce growers have been developing tomatoes that are less and less acid than they used to be according to demands from consumers. So, the tomatoes that were canned 50 years ago were probably acidic enough to can without added acid. Nowadays, they mostly aren’t. So we recommend that you follow modern tomato canning recipes and add acid, or pressure can them.

Home-canned goods in jars are so pretty! I love to store them in a sunny window so I can see the light shine through the colors. Is that OK?

No! This is an unsafe way to store your home-canned goods. Canned goods should be stored in a cool, dark place–in a basement or in a cupboard that is away from heat sources. We agree that the jars are pretty, but sunlight is one of the things that degrade food–and it will significantly shorten the shelf life of your canned goods.

The use of pH meters vs. pH testing strips

Experienced canners who design their own recipes often use a scientific tool called a pH Meter to test whether or not their food is acid enough to can. pH meters are available from scientific instrument companies, such as Weber Scientific.

We have heard reports of canning books recommending the use of pH testing strips (that you can get at the drugstore) to test the acidity of your food. We were taught that pH strips are not reliable enough to use for canning purposes. The reason for this is that storage conditions (in the store or in the warehouse or in your cupboard) can degrade them–and you have no idea how accurate they are. Therefore, we do not recommend that you use them.

(updated 8/24/20)