In a jam about jars? Read on….


There’s been lots of talk about whether it’s safe to reuse glass jam jars recently and at Friends of Glass, we’re quite flummoxed by all the fuss! Glass itself of course is absolutely safe – the issue of the original concern was about food hygiene and the importance of ensuring no bacteria can remain from previous food stuffs to contaminate your lovely new jam or preserves. So how to prevent this from happening? You must simply always sterilise thoroughly the glass containers and lids before reuse.


Still worried? here’s a few facts everyone should know about glass – please share them with your friends!


  1. Glass is inert: it doen’t react chemically with the food and drink it contains. It remains one of the purest and safest types of packaging available.
  2. When reusing glass jars, always sterilise thoroughly. The risk of contamination from bacteria doesn’t come from the glass but from any food stuffs that have not been cleaned properly from the container or lid.  Take a look at this easy tutorial on how to sterilise jars from Jamie’s food team to make sure you know how to do it properly.
  3. Glass is the only food packaging material classified as Generally Regarded As Safe (GRAS) by the US Food & Drug Administration (FDA). (
  4. There is no difference in the glass used to make Kilner jars and ordinary jam jars, beer bottles, machine-made tableware and even window glass. It is all made using soda ash, limestone and sand. Kilner jars are often bought specifically for use when making jam or preserves. They of course can then be reused again and again as with all other types of container glass, providing the above sterilisation process is followed after each use.
  5. Glass is 100% recyclable without losing quality
  6. Glass preserves the natural flavour and appearance of products for a long time without the need for preservatives. Glass containers are also easy to reseal and keep products fresher for longer once they’ve been opened.



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