Sterilising jars removes nasty bacteria which can not only spoil your preserves but even make you ill, so don’t neglect this essential step. You can easily sterilise jars in the dishwasher by running through the hot cycle, but if you don’t have one or prefer to sterilise manually, there are various other methods you can use.
Before you start sterilising jars, make sure there are no chips and cracks which could harbour harmful bugs and micro-organisms. Do not use damaged jars because they could shatter when they get hot.
Wash any jars you plan to use – including lids – in hot, soapy water and rinse well. Once your jars are clean, you can move on to sterilising.
How to sterilise jars in the oven
This is one of the easiest ways to sterilise jars. Lay your jars out on a clean baking sheet lined with paper and put them into the cold oven. Turn the oven on to 110C and leave for 20-30 minutes. Carry out this process as you are making your preserves as you want the jars to still be warm when you fill them.
How to sterilise jars in water
You can buy special water sterilising baths but you can also sterilise jars in water without any special equipment. You’ll need a large pan, with the base lined with a tea towel to keep the jars stable. Stand the jars in the bottom and fill the pan with enough water to cover them. Bring the water to a boil and hold it at a rapid boil for ten minutes. Use tongs to remove the jars from the pan and allow them to dry upside down on a clean tea towel. Again you should fill the jars while they are still warm.
How to sterilise jars in the microwave
Fill your jars about halfway with water and microwave on full power. You can stop microwaving after the water has reached boiling point and bubbled away for a good minute. Use tongs to remove the jars, then swill the water around a bit and allow to drain. Once again, fill while still warm.
Baby equipment sterilising tablets
You can use baby equipment sterilising tabs on your jars but they can leave a chemical flavour behind, so are probably best used on strong flavoured pickles or chutneys rather than more delicate jams or curds.