I can’t be the only person who used to find recipes that casually stated ‘pour into sterilized jars’ a little bit annoying. What if you’re not a seasoned pro of a jam-maker, and therefore have no idea how to sterilize jars? It makes the whole thing sound oddly clinical, like ‘sterilized jars’ are something you could buy ready-sealed, in the fashion of needles and plasters, just awaiting the receipt of your glorious ladlefuls of jam.
So, to clear up any mystery, here’s a handy guide on how to sterilize jam jars (not just for jam, of course – this works for chutney, relish, pickles, preserves…anything else you might want to store away for a few months). There are a few methods out there, including running the jars and lids through the dishwasher, but I find this a bit impractical: you don’t really want to stick the dishwasher on for a handful of jars, if there’s no other washing up to be done. It seems a waste of water. Plus you then have to be very accurate with your timings, ensuring the dishwasher is ready by the time your jam is, and jam readiness is not always an easy thing to predict.
This is the method I find the most practical and the easiest.
You will need:
Pre-heat the oven to 120C.
Fill a sink or washing up bowl with hot, soapy water. Thoroughly scrub the jam jars and lids.
Put the jam jars upside down on a rack in the oven – make sure they’re not touching. Leave them here for at least 30 minutes.
For the last 10 minutes, add the lids, upside down, on a shelf below the jars.
As I said, predicting the exact readiness of your jam isn’t always easy. Luckily you can leave the sterilized jars in the oven for a little while after they’re sterilized, with the oven turned off – just don’t open the door.
Only remove the jars from the oven when you’re ready to pot the jam, so that they’re still hot. Don’t forget to use oven gloves, and put the jars on a wooden or plastic chopping board as you’re putting the jam in.
Put on the lids while the jam is still hot, then screw them really tightly shut once the jam has cooled enough for you to touch the jars.