Over the last week, I have been jamming—literally. I made over 40 raspberry and blackberry jams for the holidays. As I sat down to write my jam recipe post, I realized that I have learned so much from my canning mistakes. I wish someone had told me the 12 canning tips before I started my canning journey. These tips would have saved me from all the messes I have made in the past.
If you have some tips to share, please do so in the comments below. If I can save one person from breaking a jar or destroying their kitchen from jam mess, I will feel I have accomplished my goal.
Let’s go!
12 Canning Tips
#1 Have Your Ingredients Ready:
Canning isn’t any different than cooking. You just finished sautéing the onions and now you need to add some cut up vegetables. Do you take the onions off the flame and then start chopping the next ingredient? I don’t.
Call me Ready Ruth or a girl scout, but I am always prepared.
When preparing jams, you move quickly from one step to the other. If I am using lemon peel, an herb, or any other ingredient, I already had the appropriate quantity sitting in a dish nearby.
Boiling a jam too long will destroy the pectin in the fruit and your jam won’t set.
#2 Don’t overfill your pot:
When making jam more is not better. Jams foam so you don’t want the foam to spill out of your pot.
I never put more than 6 cups of fruit in my pot to make jam. (I have worked with 8 cups, and it doesn’t come out as well.)
#3 De-seed your fruit:
Most people don’t like seedy jam. I don’t mind it but it is a sensory thing for some. Raspberries and Blackberries are really seedy. I even de-seed strawberries. (Remember you have to de-hull strawberries as well.)
To de-seed, you can use a strainer or a juice extractor to separate the seeds from the juice. My extractor isn’t the best so I put the seeds through two to three times to extract as much juice as I can.
On the other hand, using a strainer to de-seed fruit takes time. So be sure to allot the time.
When you are done separating the seeds from the juice, don’t throw away that seed pulp. There are plenty ways you can use it. (Another 2500 word post…)
#4 Only use the freshest fruit
Don’t look in your refrigerator on day 3 of storing raspberries and say “let’s make jam.” If you want to make jam and don’t have time, pick fresh and store them in the freezer immediately. I store my fruit until the winter since I don’t have time to make jam in the summer.
If you want to use frozen fruit from the grocery store, go ahead. Just follow Tip #5 below.
#5 Use a drip pan
If you are working with fresh or frozen fruit, make sure it can’t drip from its receptacle. When you defrost fruit, the liquid will leak out of plastic freezer bags. All that luscious fruit juice will go down the drain or in your refrigerator. What a mess. (And yes, I have lost a ton of juice in my sink.)
#6 Sterilize your jars
Once you sanitize your jars, you don’t need to do it again. Just make sure to clean them before you use them.
To sterilize, set your dishwasher on the sanitize cycle, and time your jam making to the end of cycle. Your jars will stay warm in the dishwasher.
Alternatively, you can put your jars in boiling water for 10 minutes. Many people just use their water bath canner. (You can buy one HERE) or a large stockpot. (See my discussion of stockpots and water bath canners in tip #8.)
Water takes a while to boil so do this step in advance of preparing your jam. (I use my 23 quart pressure canner as a water bath canner.)
In addition, I cover the pot with the lid of my large skillets so the water will boil quicker.
However, you don’t need to sterilize your jars if your processing time for the product is over 10 minutes.
The National Center for Home Preservation addresses this particular issue. The Center is funded by the Cooperative State Research, Education and Extension Service, U.S. Department of Agriculture. Their mission is to address food safety concerns for those who practice and teach home food preservation and processing methods. They explain:
“All jams, jellies, and pickled products processed less than 10 minutes should be filled into sterile empty jars. To sterilize empty jars, put them right side up on the rack in a boiling-water canner. Fill the canner and jars with hot (not boiling) water to 1 inch above the tops of the jars. Boil 10 minutes at altitudes of less than 1,000 ft. At higher elevations, boil 1 additional minute for each additional 1,000 ft. elevation. Remove and drain hot sterilized jars one at a time. Save the hot water for processing filled jars. Fill jars with food, add lids, and tighten screw bands.
Empty jars used for vegetables, meats, and fruits to be processed in a pressure canner need not be pre-sterilized. It is also unnecessary to pre-sterilize jars for fruits, tomatoes, and pickled or fermented foods that will be processed 10 minutes or longer in a boiling-water canner.”
Interestingly, the Center noted that some people extend their processing time an additional 5 minutes so they don’t need to sterilize the jars.
#7 Pre-heat Your Jars
For years, I have been pre-heating my jars in the oven. At first I only pre-heated them at 200 degrees. Then I decided to heat them past “boiling point.” The last time I used the 250 degree temperature pre-heating concept, I lost 2 jars in the water bather. They cracked at the bottom.
My jam jars in the water bather at the time were covered with raspberry jam. I didn’t realize until later that the jam that spilled out hardened under all the lids as well. You can’t imagine how much time it took to clean those jars.
I never lost a jar before and knew something was wrong especially when I lost 2 jars in one jamming session.
The National Preservation Center states the jars are not made for dry heat and they can crack. This is why my jars broke. They explain:
“In the provided directions, the jars are preheated in an oven (dry-heat), which is not recommended for canning jars. Manufacturers of canning jars do not recommend baking or oven canning in the jars. It is very risky with regard to causing jar breakage. There is no guarantee that the jars heated in this dry manner are sufficiently heated to sterilize them, as we do not have data on sterilizing jar surfaces by this dry-heating method.”
In the future, I will be using my dishwasher instead.
#8 Use a Water Bather
Just because your grandma turned her jars upside down after she made pickles or jam doesn’t mean it is safe now. Use a water bather or a large stock pot with a rack on the bottom. Or make your own. See HERE for a DIY rack. I never used it but it sounds interesting.
You don’t want your cans touching the bottom of the stockpot or water bath canner.
I also would suggest buying a canning tool set. They make life so much easier. (Some water bathers come with a complete set.)
As mentioned above, canning in the oven isn’t safe either.
#9 Leave the Correct Headspace
Canning recipes call for a certain headspace. Most recipes for jam will call for a ¼ inch headspace. Follow the directions. If you fill up the jars more than the headspace, your jars may not seal or alternatively, the liquid will leak out in the water.
I don’t eye ball my headspace, although I could. I use my trusty bubble popper/measuring stick (pictured above) to measure headspace.
#10 Take the Bubbles Out
Bubbles is a cute monkey but not so cute when you are canning. Remove them with a ? Slide the tool all the way down the sides around the jar to remove bubbles. Bubbles can cause pressure within the jar and cause breakage or the jar may not to seal.
#11 Following Recipes:
There are many water bathing recipes on the internet. Don’t trust them.
I follow recipes from either the National Center of Preservation or Ball Canning. (You can get buy their book HERE.) Their recipes have been tested.
There is a delicate balance of acidity required to water bath. When you start messing with a recipe by adding this herb or another type of liquid, you disrupt that balance.
Put hot liquids into hot jars. Put the jars in hot water not boiling water. Otherwise, you will have broken glass and jam everywhere in your canner.
#12 When Removing Your Jars from the Canner
Usually, you leave your jars in the water for five minutes after they processed. Then remove them. Don’t leave them in the water.
Always have a towel or a trivet on your countertop to place your processed jars. The difference in temperature between your countertop and the jars can cause them to break. In addition, don’t bother with wiping off the excess water. It will dry by itself from the heat of the jars.
I simply leave my jars alone to cool. You may hear an occasion “PING.” The jars are sealing.
Once they cool, push down on the lids to see if there is any give. If not, your jars are sealed. If there is give, then you either need to put the jar in the refrigerator or dump its contents to start the canning process again.
I have had jars not seal for whatever reason. And yes, I reprocessed them.
If they don’t seal, I store the jar and its content in the refrigerator, and later heat it up the content to re-can it with a fresh jar.
I hope my tips have saved you from loss of product, kitchen messes, and broken glass. Again, let me know about your canning experiences in the comments.
Join the Conversation:
What tips do you have in making jam?
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Renee Kohley says
Thank you for these tips! I am definitely a novice and really appreciate this post!
Julie says
I am in a canning group and something I have learned from them is always remove the rings after 24 hours. The reason being that if a jar didn’t seal, it can re-seal itself in a week or so with the ring on but it’s not a real seal and the food can go bad but you would not know this. They also recommend not storing with the ring and don’t stack jars for the same reason. I’ve been canning for 25 years and thankfully, nobody has ever gotten ill because I’ve always put the rings back on after I checked the seal!
Anna@Green Talk says
Julie, I had this happen with peaches. It was sealed and when I removed the ring I heard the popping noise. I through it in the refrigerator right away. I have to throw it out which saddens me but how do you know if it is okay even if you smell it? Anna
John the cooker says
Canned peaches or any canned fruit, if NOT sealed will NOT make a “vacuum release sound” (swoosh or suck sound) when the seal is broken as there IS NO seal to break. The fruit is the seal is bad and if it has been canned for any length of time, will be oxidized (browned) at the top (properly canned and sealed fruit when it gets some years old will often start to brown (oxidize) at the head space.
Also for hot water/hot bath canning (verses pressure canned) ABSOLUTELY NO PROTEIN foods (meat, and beans being 2 of the main foods in this category) should EVER be water bath canned. Acid containing foods can safely be water bath canned but NOT with acidified protein foods. Pickeled cucumbers or ok water bathed canned even thou cucumbers are not particularly acidic. The factor here is that cucumbers DO NOT contain proteins.
A bit confusing I will admit but a lot of things in life are confusing…….. I will not give any examples………..
Anna says
Thanks John for the tips. Anna
karen says
WOW. I didn’t know that! Great tip Julie! I certainly don’t want to get sick from poorly sealed lid. I’ll remember this next time!
Tash says
These are some amazing tips! I haven’t worked up the courage to start canning but your tips have certainly helped ease my worries! Thank you for such an informative article. Love it! <3
Anna@Green Talk says
Tash, I am glad they helped. Anna
Emily @ Recipes to Nourish says
Really great tips! I have never done any canning before. I love the de-seeding tip … I prefer mine without the seeds 🙂
Anna@Green Talk says
Emily, I had a bunch of people tell me how much they disliked the seeds. Live and learn. Anna
linda spiker says
I hate to admit this (I am a Mormon after all and we are know for canning and food storage) but I have never canned! I pinned this for when I start 🙂
Anna@Green Talk says
Linda, I will trade. I will can for you as long as you cook some of those great dishes for me. I will even bring the produce. Anna
Renee Kohley says
Thank you for these great tips! I have this one pinned for reference this summer!
Anna@Green Talk says
Renee, that is the best time to get your canning game on. Anna
Megan Stevens says
Thanks for these tips, so helpful!
Anna@Green Talk says
Megan, you are welcome. Canning is great since you don’t take up freezer space. Anna
Daja from the provision Room says
This past summer/fall was my first year canning. I learned a lot and made a bunch of rookie mistakes. But, surprisingly, I had a ball! (Get it? BALL canning jars?! I crack myself up.) Anyway, I didn’t know that I would love it, but I really do! THANKS for these great tips, too!
Anna@Green Talk says
Daja, love your humor. I adore canning. Anna
karen says
I love your canned jams! They never last more than two weeks! I never have enough pickles to can but maybe this summer, I’ll have to can my pickles! I know how much you love them! Wait. You probably can them too, right? Great post Anna!
Anna@Green Talk says
Karen, canned pickles aren’t easy. They can go limp. I usually put them in the refrigerator.
Dawn @Oh Sweet Mercy says
Great list of tips! I usually can every year though not a whole lot (not like I’d LIKE to anyway). The headspace always gets me! I’ve also been losing a lot of jars lately and not sure why, I don’t preheat them in the oven, usually just fill with hot water. I’ll have to try the dishwasher tip, thanks!
Melissa says
As I pull rings off jars I place them in the dishwasher to clean and sanitize them. When they are sry, they go into zip lock bags to be sealed until I need them again.
Cynthia wIllis says
I have been canning jams, fruits, and vegetables for several years. I have an electric smooth cooktop and it is recommended to only use pots and pans with smooth, flat bottoms on the cook surface. Ball manufactures a large water bath canner with a smooth, flat bottom. I had to purchase it online, but it fits perfectly on my new cook top!
jonique says
I lived in Australia and they add a knob of butter to their cooked jams, this eliminates skimming.
Michelle Attoe says
Great tips. I have been canning a long time this article was a refresher course for me. I really enjoyed it. There is a learning curve every time you do it you learn something more
Tomascita Edgerton says
“Perfit” seals will not confirm they are BPA free…..
Bev says
You say that you reprocess jars that don’t seal, they are not at a hot temperature to add to hot water bath so how do you get them up to proper temp?
Anna says
Bev, I changed the article to include what reprocessing means. I store the content and the jar in the refrigerator and the next day, reheat the contents and re can with a fresh jar. Alternatively, you can just refrigerate and use the contents of the jar. Anna