Open Kettle Food Processing

Open Kettle Food Processing

Food is preserved (canned) by filling hot jars with boiling food and screwing a canning jar lid on with a ring. The jars are allowed to cool, and rings are removed, leaving sealed jars of food.




To process (can) food by open kettle, you will need these things:

  • A pan (with a lid) that is large enough to hold the jars you will be filling with food. (Estimate how many jars you will need.) Also, a rack or old folded towel needs to be placed on the bottom (so that the clean jars aren't directly on the bottom).
  • A jar lifter** or heavy oven mitts**.
  • Canning jars, cleaned and inspected for chips or cracks. Your jars must be chip-free at the top so that the lid will seal.
  • Canning jar lids and rings; both should be washed, and lids should be brand new (never used).
  • Wooden cutting boards* or folded towels*, to set hot jars upon to cool.
  • A ladle for filling your jars, and a funnel (preferably a wide-mouth funnel for ease of filling and less mess).
  • A wet washcloth.
  • A small pan filled with water, for heating lids, and a fork for removing them.

Set up:

NOTE: I have recently added a video blog demonstrating how to open kettle can tomatos. Also, see additional notes below for important information about this method of food preservation.

1. Make an area for finished jars to be set. Fold towels or use wooden cutting boards.

2. Heat small pan of water to boiling. Reduce to simmering. Add canning lids shortly (5-10 minutes) before you will need them. The lids need to be hot, but over-boiling isn't necessary. Set a clean fork nearby to use to remove lids one at a time when ready for them.

3. Arrange clean empty canning jars in your large pot or canner. (Be sure to place a rack under the jars, or fold an old towel on the bottom, so that jars aren't sitting directly on the bottom of the pan.) Fill bottom of pan with about 4 inches of water. Put lid on pan, and heat until water is at a hard boil. If your caning is going to take a long time, be sure to monitor the water level in this pan so that it doesn't boil dry. Have a potholder or oven mitt near this pan for lifting the lid each time you need a jar. Place your jar lifter** near here, also.

4. Be sure you have a heat-safe working area next to your pan of boiling food (that you will be canning). This can be done either on the stovetop, or by placing a wooden cutting board* or potholders on your countertop. Place your wet washcloth nearby, along with a ladle and funnel (for filling jars). Place your clean jar rings near here, also.

5. You will also need your food, of course, which should be at a boil while you are canning. Not all things can be open-kettled (for safety reasons), but things like tomato soup, tomato salsa, pizza sauce, etc. do very well with this method.

6. Lastly, be sure that you can give your undivided attention to the process once you have begun. It's inconvenient to stop while open kettling, and your food won't turn out as nicely. So, carefully set everything up and plan for some excitement! ;) Open-kettling is a fun, one-person job! :)

When you've gathered all of your supplies, and you're all set up, here's what you do:

1. Remove one hot jar from your kettle, replacing the lid. Set jar on heat-safe working area next to your pot of boiling food.

2. Ladle food into jar using funnel, filling to between 1/2 and 1 inch from the top.

3. Wipe top of jar to remove any food residue from rim (where lid will be placed) to ensure sealing.

4. Using fork, remove one hot lid from your simmering saucepan of lids, and place lid on top of jar.

5. Screw a canning jar ring onto your jar, tightening snugly (but not as tight as you can possibly make it).

6. Place finished jar on the towels or other heat-safe area you have prepared.

7. Continue filling jars until your food is all canned. Jars will seal as they cool.

8. Wait until jars are completely cooled (about 12 hours) before you remove the rings, wash the jars, and label with item and date.

Tammy's Video Blog

Demonstration Video

Additional Notes: 

*I like to use wooden cutting boards rather than potholders when possible because they are easier to clean up afterwards.

**A jar lifter is a handy canning tool, but I have canned using oven mitts to move hot jars. If you use oven mitts, try to use ones that go high up your arms (or wear a sweatshirt) and be careful of hot steam.

NOTE: Open-kettle canning is no longer recommended; experts determined that the food doesn't reach a high enough temperature. Therefore, I can't endorse this method, although I personally continue to use it for high-acid foods.

Tomatoes are no longer considered a high-acid food. To increase the acidity of your tomatoes, add 2 tablespoons of bottled lemon juice or a half-teaspoon of citric acid per quart of tomatoes.

So, here's what you need to do: Follow the instructions here for filling your jars, and then put your full (hot) jars into a canner. Fill with hot water, up to about an inch below the lids. Cover canner. Bring to a boil and cook for at least 85 minutes. Remove jars from canner and allow to cool before removing the rings.

Preparation Time: 


Tammy's Review: 

This is my favorite way to can food! I prefer to can salsa, tomatoes, and cherries by this method. I like that it's fairly quick (no long boiling times) and I personally think it's fun to fill the jars and get the food all processed. :)


This is a very easy method to can food and is the method we like to use for canning salsa or diced tomatoes, especially. The video is especially easy to follow and is only 2 minutes long.


Finding foods that can be canned this way takes a lot of the intimidation away from home canning. Pressure cookers are often fussy and this alternate technique is great for jams and jellies.


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