Demystifying Water Bath Canning

You would not believe the number of people I encounter over a year that still do not understand the difference between water bath canning  and pressure canning. There is an equal number of people who still do not know what is safe to can in a water bath canner and what is not. Here are a few facts about water bath canning that should hopefully clear up the confusion.

What IS the Difference Between Water Bath Canning and Pressure Canning?

To put it simply a water bath canner cans at the boiling point of water which is 212 degrees Fahrenheit. Using a pressure canner increases the temperature to 240 degree.

The reason why water bath canning is not always recommended is because some foods have the potential for bacteria thriving in them that cannot be killed at lower temperatures. These foods are called low acid foods. The bacteria cannot live in high acid foods so easily so it is considered to safe to can these foods at lower temperatures. The higher the acid the less likely that these bacteria will take up residence. If you are canning low acid foods then a higher temperature is needed to kill of that bacteria. While you can use  a ph meter to check the ph level of foods to see how high or low in acid they are, you can also use this chart to determine whether your food is safe to water bath can. If foods are borderline and you are not sure the phmeter can be a great way to make sure what you are canning is safe.

A PH of 4.6 is the border line, anything above this is considered a low acid food, some things like tomatoes can have lemon juice added to them to increase their acidity while other things must be processed in a pressure canner. Anything below 4.6 ph is safe to can in a water bath canner.

This also means that when you are canning tomatoes or pickles, if there is vinegar or lemon juice in the recipe you must not decrease this amount, as it makes the food safe to water bath can. You should also never increase the amounts of low acid foods in these recipes – they are formulated to ensure they are high enough acid to water bath can. If you must change the recipe, play it safe and pressure can it.

Table of Example Foods to be Water Bath or Pressure Canned

This list is a sample just to give you an idea of what foods can you safely can in a water bath canner. There are many more foods that will fit in these lists, most of which will go in the list that corresponds with the type of food it is.

5 Important Questions Answered about Water Bath Canning

If you are new to canning, there are dozens if not hundreds of tips that can help you along the way. But there are a few procedures that must be followed to ensure that your canning is successful but most importantly safe.

1) Always Use a Rack in Your Water Bath Canner Similar to the One Shown in this Picture – Water Bath Canner The rack allows for even heating, and prevents the jars from getting too hot on the bottom or breaking.

2) Jars Must Always be Sterilized – When pressure canning you do not have to sterilize jars because the heat is sufficient to do it for you. But when water bath canning you must sterilize the jars and the lids. This is to ensure that bacteria is killed before you fill them. You should keep your rings and lids in water kept at a simmer until you put them on the jars.

3) Clean Both the Tops of the Jars and the Outside of the Top of the Jar Carefully Before Sealing. This part is often missed and very important. Clean up any drips or spills around the ring and the top of the jar. These can not only interfere with sealing they can also leave an avenue for bacteria and spoilage.

4) Never Re-use Lids – This is very important because a lot of people try to reuse the disposable lids thinking that if they reseal all is well. The truth is these reused lids can and do fail, leaving you with a spoiled product. The only exception to this is if you used tattler lids or any of those similar to them. These lids can be reused 4 to 5 times safely before you have to discard them. You do pay more for them, but you get more in the long run. Tattler Reusable Regular Canning Lids and Rubber Rings, BPA Free, Dishwasher Safe (Pack of 12)

5) Always Check Seals – Water Bath canning jars do not always seal right away but they should always seal. If they do not, you have two choices, you can either put unsealed jars in the fridge and use them up right away, or you can try to seal the jar again with a new lid but you must process the food again for the full amount of time.

6) Inspect Your Jars Periodically – Seal failure happens and so does spoilage. Much of it can be avoided by following the tips above, but you should still check jars periodically for failed seals and spoilage. Bacteria spread rapidly so the faster you catch it, the better off you will be.

Remember however that you cannot see all bacteria, some bacteria will leave food looking perfectly normal. Check for lids that bulge or foods that are bubbling. These are signs that your food might be spoiling. It is always better to be safe rather than sorry so if in doubt throw it out. Your best defense is simply to follow all of the guidelines carefully and then spoilage and broken seals will be kept to a minimum.