A water bath canner is a large pot with a jar rack. It is used with all high acid foods. This includes: all fruits, jams, jellies, pie fillings, pickles or condiments and tomatoes with added lemon juice.
If you have any low acid foods or ingredients you must use a pressure canner.
I often get asked if you must use a water bath canner or can you use a regular pot. The great thing is... no, you don't HAVE to have an actual canner.
Any pot will work as long as it is deep enough to have 2 to 3 inches of water covering the tops of your jars as it boils.
It must also have a rack to keep the jars off the bottom of the pot. The water must flow around the jars and the jars must not touch the bottom of the pot.
However, I must add that water bath canners are pretty inexpensive. Plus a pot specifically made for water bath canning makes things very easy. It will come with a rack for your jars already.
On a standard canner this rack will have "hooks" on the handles that will hook to the side of the canner and hold the jars up out of the water. Then the jars can be lowered into the canner when ready.
If you are using a stock pot, you can use what ever you have on hand as a rack. It does not need to hang on the side of the canner. The rack can be as simple as a rack from a round roasting pan. What ever will fit in your pot. It's most important function is keeping the jars off the bottom.
I would recommend getting a stainless steel water bath canner. They are a bit more expensive, but are a higher quality product and will last.
The stainless canner is much sturdier and doubles as a stock pot for other cooking. I've heard that stainless steel caners can be used on flat top stoves. I don't have personal experience with this, socheck with your stove manufacturer; however the makers and reviewers say it is perfectly safe.
This Victorio is the Canner I'd recommend if you are looking at the stainless steel.
Finally there is the steam canner. Not to be mistaken for a pressure canner, this type of a canner is sold as a substitute for a water bath. The jars are placed in the shallow bottom portion with water. The top is placed over the jars. The water is brought to a boil which causes steam to build up inside.
You should know that there is some debate over the safety of steam canning. A couple of state extension services have tested them and called them safe. But others have not tested them and so won't recommend them. Read more here and make an informed decision for yourself.
I have heard good things about this canner and I love the idea of only heating a few inches of water. You'll have to be the judge as to whether this is safe for your family or not. Do NOT use these with any low acid product. No Vegetables, and No Meat. Check the instructions that come with the canner for directions and timing suggestions.
Since I put up a lot of jars each year, I wanted to purchase a large capacity pot in order to jar nine quarts at a time. I put off purchasing one because I was concerned about how it would fit on my standard sized stove.
One day I was at an auction and there was a beautiful blue large 9 quart water bath canner--complete with jars! I bid on it and won!! I got it at a great price. I love auctions!
This larger size pot fits over two burners on my stove, and it works perfectly fine.It does take longer to heat. This is to be expected because it holds so much more water. If I am canning a lot of something it is nice to be able process nine quarts at a time. When canning several batches in a row, the canner does not have to reheat all that water as it is already hot from the first batch. The heating time is more noticeable only when I have a single batch to process.
The rack with this canner does not work well with the smaller pints and half pints. They tend to slide through the gaps. In addition, there would be so much wasted space between your jars, you'd be heating much more water than necessary. I'd recommend replacing with a different rack if you plan on doing many pints or half pints.