Why do biscuits go soft? © iStock

Why do biscuits go soft?

Biscuit tins were invented for a reason – so find out how they keep biscuits biscuity for longer.

Unlike bread and cakes, which tend to become hard the longer they spend in the air, most biscuits go soft over time. As in bread, starch from the flour in biscuits begins to crystalize after a few days, theoretically making biscuits more brittle. But in many biscuits, the high sugar content masks this process by absorbing water from the atmosphere, ultimately resulting in a soft biscuit.


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.