Food
Fact-checked

At DelightedCooking, we're committed to delivering accurate, trustworthy information. Our expert-authored content is rigorously fact-checked and sourced from credible authorities. Discover how we uphold the highest standards in providing you with reliable knowledge.

Learn more...

What is Open Kettle Canning?

Mary McMahon
Mary McMahon
Mary McMahon
Mary McMahon

Open kettle canning is a method of food preservation that involves putting boiling food into extremely hot jars and then sealing them. This method of canning is not recommended by numerous food safety organizations, including the United States Department of Agriculture. However, it can help to understand what the process is because this will make it easy to identify and avoid. As an alternative, cooks should consider canning in a pressure cooker or in a boiling water bath, as these two methods are much safer.

In open kettle canning, one pot is used to heat the food that is being canned, such as tomato sauce, while canning jars, rings, and lids are kept in a pot of boiling water. The cook removes one jar at a time, fills it with boiling food, and quickly seals it, setting it aside to cool. Once totally cooled, the canning ring can in theory be removed, although many people like to leave it on.

A canning jar of pickled cornichons.
A canning jar of pickled cornichons.

Some people use this as a shortcut method, because it is fast. If you plan on refrigerating or freezing the food afterwards, open kettle canning is an acceptable technique. However, for long term preservation and preservation at room temperature, it is not a safe canning method. Recipes which recommend this canning technique should be viewed with suspicion.

The primary problem with this canning method is that it does not raise the temperature of the food enough to eliminate many harmful organisms. In a pressure cooker or canning bath, the food is raised and held at a high temperature, ensuring even distribution of heat, and this kills the majority of organisms that could be potentially harmful. Open kettle canning also leaves a number of opportunities for contamination.

Organisms can be pulled from the counter or tools used to handle the food and jar, for example, and they can also be introduced into the pot used to boil the jars by sloppy cooks. Under normal circumstances, if a little bit of bacteria is introduced into a jar while the food is being packed, it is not a cause for concern, because the bacteria will be killed when the jar is boiled again. However, there are no second chances for getting rid of bacteria, mold, and fungi in open kettle canning, and as a result there is a high risk that the food will go bad, especially if it is held at room temperature.

Mary McMahon
Mary McMahon

Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a DelightedCooking researcher and writer. Mary has a liberal arts degree from Goddard College and spends her free time reading, cooking, and exploring the great outdoors.

Learn more...
Mary McMahon
Mary McMahon

Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a DelightedCooking researcher and writer. Mary has a liberal arts degree from Goddard College and spends her free time reading, cooking, and exploring the great outdoors.

Learn more...

Discussion Comments

anon1002233

Bacteria are different nowadays, and pressure canning is not particularly onerous. Why play Russian roulette?

anon352686

I have to say, I've enjoyed all the comments. I use all three methods. When my husband helps, he doesn't think that everything needs to be perfectly clean, so reboiling it is the best bet for my household. However, when my husband isn't around and I have a small batch of something or I'm trying to can something, I know is going to be used kind of soon, the open kettle method is fine. We even use the microwave for heating the water.

We can everything. We're sick of the all crap the USDA says is "OK" to have in your food, like bug parts or rat droppings. I can guarantee my food is safe to eat and has no bugs or droppings of any kind.

anon291079

Interesting how society says we can't take any chances with canning (hence everything must die including the nutrients in the food), yet thousands of people per day take a chance and play roulette injecting their babies with toxic substances that can lead to brain damage and death on the chance that they could happen across a virus and not be able to fight it off. Where are we headed here?

anon187282

I use this method to can apricot preserves. Processing will over cook the fruit and it loses its desirable texture.

The business end of anything that even goes near the jars is placed in boiling water for at least 10 minutes (tongs, knife for removing air, funnel, even the bands). I put the jars in the oven at 230 F for at least 20 minutes after hand washing in scalding hot water with lots of soap or in the dishwasher on the sanitize setting. All lids and jars are inspected for any adherent material (or defect) before they go in the oven. Any lid that I do not personally witness "popping" or does not have an unquestionably fixed concave lid is a jar that is refrigerated for immediate use (rarely happens).

Acidification of the apricots is best done with a heaping tablespoon of Tang and one teaspoon of lemon juice. This method "brightens" the flavor as well as lowers the pH. By the way, only the small Manchurian style apricots in their firm state, can be used. The newer big apricots commonly found these days have too much water and will turn to soup in the kettle. Best to mix fully ripe and almost ripe fruits for best texture. Wash thoroughly to remove any visible dirt, then pull them in half. They get boiled in the sugar for about 5-8 minutes – just long enough without overcooking the fruit.

Above all, once you start the process you must complete it all at once, paying 100 percent attention to what you're doing to avoid contaminating your product. Send the husband to the golf course and the kids to the movies. Put the dog in the yard.

If I'm making a large batch that will likely be shelved for more than a couple of months, I put them in boiling water for 10 to 12 minutes, but the drawback is you can overdo this and the product will overcook and loses its desirable texture.

I no longer distribute or serve this product to anybody outside my household. Too much fear mongering and too many lawyers.

anon181513

Too many "experts", not enough education. The modern tomato may not have sufficient acid for "open kettle". When the acid is not present, C. botulinum can grow. What I've done is bought pH paper to test the pH, so that I know the food is 4 or below. (lower number, higher acid, higher number more base).

I don't want to die of stubbornness or nostalgia, but I also don't want to heat up the kitchen and spend hours canning the tomato juice. I'd never get a year's worth of juice done if I added an hour to hour and a half of prep time per seven quarts of juice. (recommended time for my elevation is 90 minutes).

Grow your own heirloom and old varieties of tomatoes, check for proper pH, and do what you think is safe.

anon114193

if you somehow contaminate whatever is in your jar, and something starts growing in it, the lid should bulge and you will not have a vacuum seal. if an organism is living and eating the sugar inside the jar, it is giving off gas. You'll know! i would use the hot water bath for things like pickles that need to be acidified, but most fruit contains enough acid.

anon111014

We did all of our tomatoes (high in acid) and jams and fruits, such as: apricots, pears, peaches open kettle. My mother would not do any other vegetables so we froze corn, beans etc. We did this for 40-plus years and never had problems. We store them in the basement and always used them within two years.

anon97332

Wow, I know my grandmother used this method and she lived to be 86. I think open kettle canning may help you live longer. lots of laughs. Besides when you add hot liquid to a hot jar it stays hot for hours. This article is ridiculous.

anon92560

I was taught by my great-grandmother how to can using the open kettle method of canning and personally have no issues as yet.

I do however use a pressure canner when electricity is available. However, having grown up in and moved around to a number of places considered backwoods I can honestly say electricity is not always an available luxury. For this situation, open kettle is the best you are going to get.

I take it on faith that if we as humans have survived this long, the race will continue on, albeit at a higher risk of personal pain, but hey it is what it is.

yvonnelh

All postings from people who lived to tell. And the ones not so lucky?...

In my opinion, re-processing cans again in boiling water/pressure canner is pretty easy, especially considering the potential consequences.

anon54274

Wow - 3 people still alive to post about their open kettle experiences. Where are all the dead people who didn't live to tell? Oh yeah...

Personally, sticking the jars back in a pressure canner or boiling water bath to cook out the pathogens and not accidentally kill my family with food poisoning is an infinitesimally small inconvenience considering the consequences.

No need to be stuck in old ways just for the sake of convenience or "tradition." Washing before surgery and delivering babies is also a fairly modern concept, but one worth embracing!

anon46205

I can my salsa this way and have for the last 10-plus years as the generations before me did and I agree, there is *no* way I could be "lucky" for that long! I always make sure my counter and everything is clean! I love this method!

anon39399

My mother, my mother's mother, and my mother's mother's mother all used this method and lived to tell about it. I have used it for years to can jam, tomatoes and peaches without any problems.

anon35398

I am 72 years of age and have always done all my canning by Open Kettle Canning. I am still alive and my food stays good for quite some time. I find it hard to be "lucky" for this long of a time. If indeed it is luck.

Post your comments
Login:
Forgot password?
Register:
    • A canning jar of pickled cornichons.
      By: ChantalS
      A canning jar of pickled cornichons.