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.
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.
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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