My oldest memory of canning involves Mason jars, sterilization, stock pots, time, effort, logistics, division of labour, etc. – basically a big overwhelming production for a few jars of pickles. In this episode I discuss a method of preserving any sort of ‘acidic’ preserve that is very easy to do, and can be scaled down to a single jar for optimum simplicity and convenience.
The method of canning that I am going to discuss in this episode is called ‘microwave canning’. Every official source that I have consulted on this technique says that it is not safe.
Here a list of links to websites that argue against microwave canning:
Oregon State University (pdf download)
All of these websites say that water bath canning is the only way to go – but all of these resources as far as I can tell are talking about canning in general – and are not being specific to the canning of highly acidic preserves. My understanding is that Clostridium botulinum (the bacteria that creates the toxin that causes botulism) cannot grow at pH levels lower than 4.6 (except when in a protein rich environment). Given that typical white vinegar is 5% acetic acid, and thus, has a pH of approximately 2.4, I am personally willing to roll the dice with pickles, vinegars, and chows because they all employ white vinegar and are not protein rich environments. They also may or may not have sugar or salt – ingredients which further tend to inhibit bacterial growth.
All of this having been said, do your own research and use your own judgment.
Microwave canning is fairly straightforward:
1) Sterilize your jars, lids, funnel and utensils – I do this by placing them all in an electric kettle and letting it come to a boil a couple times – this is handy because if you get delayed, you can just hit the button and boil again whenever you can.
2) Bring the material (pickles/chow/relish/etc.) that you wish to can to a boil in a saucepan.
3) Put the material in the jar(s) – make sure not to get anything on the rims of the jars.
4) Put the jar in the microwave and let it go on high for about minute – what you want is to get it just boiling, but not overflowing – this will take a little trial and error, and will depend on what you are working with and the size of the jar- just make notes and you’ll figure it out given enough iterations. While this is happening – give your kettle one more boiling session – that should take about a minute as well.
5) As soon as the microwave shuts off, take the lid with your tongs, and place it on the jar. Snug the rim down gently and place the jar somewhere to cool. After about 15 minutes you should hear the lid snap, which will indicate that you have achieved a vacuum within the jar – you will also note that the lid is somewhat concave at this point.
6) Store in your pantry and eat within the next few months. I’ve never stored anything longer than 9 months using this method. If you are nervous, put the jar in your fridge and eat it all next week.
The sense of satisfaction that you will gain from filling your pantry with jars of preserves from your own garden is something special, and for me it’s an integral part of the gardening experience. Over time, you will develop recipes that you prefer over store bought options – and of course – you will save money. Whether you roll the dice with microwave canning, or go the safer, tried and true method of water bath canning, try canning this fall – it’s one more way to continue enjoying your garden while it takes a long winter’s nap.