Every year during harvest season thousands of people try their hand at canning their own food. Some people can to preserve all the extra goodies from their garden, some can to make frugal gifts, and others can to conquer yet another cooking technique. However, before you roll up your sleeves and start prepping your kitchen for a long canning season, you need to learn what things can and can not be safely canned.
Furthermore, you need to recheck sites like the USDA and local extension offices to see if canning recommendations have changed over the past year. Times and pressures for some products may change from year to year, so it is imperative to double check all of your canning recipes before you start canning. In his digital age, there is no excuse for not seeking the latest recommendations. Listed below are things that should never be canned.
1. Dairy products: No milk, cheese, yogurt, or any other dairy products should be canned. The only time it is considered acceptable to use butter when canning is to use a small amount when canning jams and jellies to remove the foam from the top of the pot right before poring in hot sterile jars.
2. Pumpkin butter/soup: Pumpkin butter is a very popular item to make during the fall season, but the thick pumpkin puree can not be safely canned. Your grandmother may have canned pumpkin butter all the time as a child, but our knowledge of food safety has grown and this product is no longer considered safe for canning because the thick puree does not allow for even heating all the way through the jar.
3. Pureed soups: The USDA recommends that soups be half solid mixture and half broth. This means no purees. Some older canning books often puree beans or other vegetables to make a thicker soup, but this not recommended. Soups can be pureed after opening.
4. Flour, cornstarch, tapioca, or other thickening agents: Thickening agents should be used after opening the sealed jar of food. ClearJel is the only USDA approved thickener for canning. However, ClearJel is only approved for fruit pie fillings and some pickles. Do not use recipes that use ClearJel for tomato sauce, stews, soups, or canned vegetables.
5. Summer Squash: Summer squash including zucchiniis no longer recommended for pressure canning because processing times for summer squash can not be verified. Summer squash gets very mushy during canning causing a very dense pack inside the jar causing uneven heating. Summer squash can still be pickled safely. Luckily, summer squash freezes well and dehydrates well.
6. Fatty cuts of meat: A high fat content in pressure canned recipes can cause a poor seal and produce strong unwelcome flavors. Lean cuts of meat such as chicken breast, flank steak, pork tenderloin and best for canning. Leave your bacon in the freezer.
7. Unsoaked and uncooked dried beans: There have been a lot bloggers posting about the “easy way” to can beans where you put dry beans in a jar and cover them with water and pressure can them. This is not safe. You soak beans to remove phytic acid and by cooking your beans in the same water that you soaked your beans in you are not removing the phytic acid. Furthermore, dry beans are very dense and hard. You pressure can beans to kill any bacteria that may make you sick, but when you pressure can beans that are not hydrated, you are not giving the pressure canner enough time to kill harmful bacteria. UPDATE: A lot of people have read this post and think that I am against pressure canning dry beans. I am all for pressure canning dried beans if they have been soaked and cooked until 3/4 of the way done before pressure canning. I am against taking dried beans and putting them directly in a jar with hot water and pressure canning these beans without soaking or cooking.
8. Rice, noodles, barley, and other grains: Grains should be added to canned goods after the jars are opened for serving.
9. Avocados: Avocados have a high fat content making them not suitable for canning because they cause a poor seal.
10. Whole strawberries in syrup: Strawberries are very popular for canning, but they do not can well whole in sugar syrup because strawberries turn pale and lose flavor while sitting on a shelf. Save your berries for jam or pie filling.
11. Sage: Sage turns bitter when canned. If you want to use sage, then add it to your canned food after opening the jar.
12. Eggs: Eggs should never be used in home canning products. Even pickled eggs should be kept in the refrigerator at all times except at serving time. Room temperature pickled eggs has caused botulism, so it is best to keep all egg products out of canning.
The list of the following things should be canned under certain circumstances:
1. Basil: There is reason why you do not see a lot of canning recipe using basil. As a canned item sits on a shelf, the flavors change over time. Basil has a tendency to taste bad over time, so this delicious herb should be used sparingly when canned. You can always add fresh basil to a canned item when it is opened.
2. Oil: In general, you should not use oil when canning. However, there are some circumstances when oil can be used. For example, in my favorite roasted Roma tomato sauce uses oil to roast the garlic. Whole garlic is doused in oil and roasted in the oven. Then, the garlic is peeled and used. The argument is that most if not all of the oil is left on the baking sheet or on the garlic peel. A small amount of oil can be used to sauté or cook meat for pressure canning. Always use the oil very sparingly.
3. Fresh lemon juice: This may sound counter intuitive, but if you are using lemon juice to acidify tomatoes or other produce, then use bottled lemon juice. Bottled lemon juice has a constant pH while freshly squeezed lemon juice can vary in pH depending upon the variety of lemon. If you are using lemon juice for flavor like in my strawberry lemonade concentrate, then use freshly squeezed lemon juice.
4. Heirloom fruits and vegetables: Most recipes are tested using common varieties of fruits and vegetables, but the adventurous gardener likes to expand into white tomatoes or low acid peaches. When you work with heirloom vegetables, you need to make sure that the pH of your canning recipe has not been altered too much. If you are unsure of the safety of your heirloom fruits and vegetables in canning recipes, then it is probably best to dehydrate or freeze your heirloom produce.
5. Fresh orange juice: If you are lucky enough to own an orange tree, then you are probably lucky enough to have more orange juice than you can realistically drink during orange season. Unfortunately, as blogger Kris Simply Living found out, fresh orange juice turns into a bitter mess when canned. A small amount of fresh orange juice can be canned with other things for flavoring or turned into marmalade, but save your large quantities of orange juice for the freezer.
6. Melons: Some fruits change texture when canned. Watermelon does not can well. However, if you are really adamant on preserving watermelon, then the rinds can be pickles or preserved. Small quantities of cantaloupe chunks can be canned along with other fruits or the juice is excellent when combined with peach juice, but you probably do not want to can large amounts of melons in syrup.