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How to sterilize jars

The easiest way to sterilise jars

by Cybele
My favourite way to sterilise the glass jars and metal tools is in the oven. The scientific boffins seem to agree that sterilising in the oven or in a “Dry heat at 160 °C (320 °F) for 1 hour” is a pretty good way to go. Hotter than 180 °C (350°F) and you risk cracking glass. It made my day to read that they thought boiling was not as effective (unless combined with a chemical disinfectant), because I hate playing ‘go fish’ with glass jars and boiling water. It always ends in tears…
If you don’t have a dishwasher it’s fine to hand wash before putting in the oven. It’s just that dishwashers are able to work at much higher temperatures, like 140°C (280°F.)
The other thing you need to think about is what you are putting in the container and at what temperature. Hot food or cosmetics needs to go in hot jars and cool food or cosmetics need to go in cool jars. So you want to time your sterilising with your goodies being ready. Basically, you want the container to be a similar temperature to what is being stored.

How to sterilise glass containers and metal tools

1. Preheat oven 160-180°C or 320-350 °F
2. Rinse tools and jars well and stack in dishwasher with a fairly light load, ideally with other glass jars and put through a cycle or hot hand wash with soapy water and rinse.
3. Stack jars in oven, mouth down and any tools so that water is able to drip out and you don’t want anything touching. Close the door and leave for at least one hour.
4. If you’re using the jars for preserving hot food, like jams and the like, use tongs to remove and fill straight away. If you’re filling the jars with cooler goodies, you can turn off the heat and let the jars cool down before plucking them out.
If you don’t have an oven or have plastic or rubber bits and bobs and would like to sterilise in boiling water,  these guys have instructions and some for the microwave too.

The best way to look after your goodies once open

Foods need to go in the fridge. Cosmetics that don’t have water in the mix can last varying times outside the fridge, depending on the shelf life of the ingredients. Be guided by the use by dates on the packets and aim to use up before. Unfortunately, unsterilized jars, warm humid environments, any water in the pot and grubby fingers can shorten their life span, so always look out for the warning signs, like changes in colour, smell and look.
It’s also worth thinking about using clean spoons to scoop out your goodies to avoid introducing nasties into the mix. I have lots of those short, plastic medication spoons that I rotate in and out of the dishwasher.
I also put the products I use everyday, especially those used in a steamy shower or bathroom, in small jars that I can use up quickly.
It’s funny, because I am much better at using my homemade products, because I know they won’t keep forever so there is no point in saving them for ‘special occasions’, whatever they are anyway…
I would love it if you could share your tips for sterilsing and making homemade goodies last longer. Many brains definitely help and I am keen to find out more.



About BlahBlahMagazine

Cybele Masterman (Bele) trained as a beauty therapist, aromatherapist and journalist. After working as all of the above has found herself on a quest for a beautiful and meaningful life that doesn't cost the earth. Follow on google: +blahblahmagazine twitter: @blahblahzine or Instagram: BlahBlahMagazine

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  1. My grandmother used to preserve all the fruit she got from her garden, as she lived in Melbourne and there was lots of it. I am now the lucky recipient of those mason jars complete with metal lids and clips. Thanks for educating me on how to sterilise them. I really should preserve some fruit in her honour. Sad how its just easier to buy it in a can these days.

  2. My oven doesn’t go below 170… any other suggestions?

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