How to ‘Dry Can’ Acidic Foods

Dry canning has been around for generations.  Our grandparents and great-grandparents would use this method in making jams, jellies, and tomato sauces.

Dry canning is the method of sterilizing your mason jars in an oven, soaking the lids in hot boiling water while the jars are in the oven, and making the tomato sauce or jams until everything is extremely hot, sealing with hot lids and rings, and setting the jars onto their lids for several minutes to seal.

This method is perfectly safe to use with highly acidic foods such as citrus fruits and tomatoes.  One should NEVER use this method for vegetables and/or meats of any kind! If foods are not acidic, in order to can them and preserve them properly, they must be pressure-canned!

Not too long ago, I found a great bargain on 4lb bags of tomato sauce for only $1.49 each!  I use tomato sauce in much of my cooking, i.e. chili, spaghetti, et al. It is only my husband and me and so I use canning as a great method of preserving large quantities of ingredients into manageable portions. That is exactly what I did today, and I will share with you the process I use to dry can the tomato sauce into pint-sized jars.

EQUIPMENT NEEDED: (all links below are products from Walmart, but you can buy them anywhere!  I simply wanted to give you an example of  what they look like.)

[NOTE: I use this canning kit from in case you’re interested.]

STEP ONE: Sterilizing your equipment

  • Turn oven on to 250ºF (121ºC)
  • Remove lids and rings from mason jars and arrange jars on a baking tray. (I used a large pizza pan, and it fit the 12 jars needed for my amount perfectly!) Let them sterilize in the oven for 15 minutes.  Then turn off the oven, but DO NOT REMOVE THE JARS. Let them sit in the hot oven until you are ready to use them.


  • Put lids in a heat-proof bowl or pan and cover with boiling water. (To heat your rings, put these under boiling water as well, or in the oven with the jars. Do not put the lids in the oven, as this will only dry out the rubber seal and you don’t want to do that.)


STEP TWO: Cooking

Heat up the food to boiling, and/or make whatever jam/jelly recipe you want to make while everything is sterilizing. (For the tomato sauce, I heated it until it bubbled up like molten lava – very carefully and on med-low heat, stirring constantly so it didn’t splatter and spit everywhere!). You want the contents you pour into the jars to be extremely hot!


STEP THREE: Pouring contents into the jars

  • Quickly remove only 4 jars from the oven at a time, upright onto a toweled surface.  This protects the countertop from the heat, as well as protects the jars from slamming onto a cold, hard surface and cracking.
  • Using a canning funnel and ladle, pour contents into hot jars until it comes to about 1/2″ or 3/4″ from the top.


  • Dip a clean paper towel or rag/cloth into the hot water covering your lids to moisten it, and thoroughly wipe the rims of each jar to clear it of any food drips.  This prepares the jar for a good seal!  While doing this, it also allows you to feel for any chips or cracks on the surface of the rim that you may not catch with the naked eye.  (While doing this batch today, I was using well-used, older mason jars, and two of my jars had small chips along the rim, and I had to throw them out and sterilize new jars to replace them.)


STEP FOUR: Sealing

  • Using the magnetic lid lifter, take one lid out of the hot water at a time, place it on a full jar, (after cleaning the rim, of course) and then screw a ring onto the lid and tighten it down as tight as you can.  You may need to use a pot holder or towel to protect your hands from the hot jar(s).
  • Turn sealed jars onto their lids and leave them to cool a bit, for at least 15 minutes!  Some do it longer, but I’ve found that 15 minutes works perfectly.


While these jars are waiting upside down, remove 4 more jars from the oven and repeat the process until all the contents are used up and all jars needed are filled.  It is much better to have sterilized more jars than you need… than to fall short!  I usually sterilize quite a few more jars than I think I need, just to have everything ready and on-hand.  Today, however, I knew I needed 12 jars for the amount of sauce I had and stuck with that amount, and as mentioned earlier, two of the jars were chipped.  I had to keep the sauce warm and wait for 15 more minutes for the two spare jars to sterilize before continuing on.  It was a pain!


After 15 minutes (or longer), turn the jars upright, and enjoy the “ping” as they seal!!!  Leave them for 24 hours or until they are completely cooled to room temperature before removing the rings, labeling and storing.



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