What is chewing gum made of?

Asked by: Willem Davies, Bradford

Chewing gum has been with us since the Stone Age – chicle gum was made from the sap of the Sapodilla tree. Most modern gums are based on a synthetic equivalent, a rubbery material called polyisobutylene that’s also used in the manufacture of inner tubes. Polyisobutylene is mixed with plasticisers and materials – all food grade – to make the gum mixture chewable.

The success of chicle and polyisobutylene lies partly in the narrow temperature range over which materials soften. So a material that’s firm and easy to mould becomes soft and pliable in the warmth of the mouth.

Read more:

• Can chewing gum help you concentrate?
• Does chewing gum really stay inside you for years?

Subscribe to BBC Focus magazine for fascinating new Q&As every month and follow @sciencefocusQA on Twitter for your daily dose of fun science facts.