Cookies at Nordic Sugar’s websites
At our websites we use cookies to collect statistic information in order to optimise the use of our website. By proceeding further into our website, you accept our use of cookies. Read more about our cookie policy and instructions on how to delete cookies.
Accept cookies
  
You are here:

Shelf life of jam and marmalade

Sugar increases the keeping qualities of jam and marmalade.

When sugar is added to jam, water activity is reduced because the sugar binds water. The lower the water activity, the better the keeping qualities.

Microorganisms can only grow in "free water" in food products. If water activity is sufficiently low, microorganisms cannot decompose the food.

A sugar content of 500 g per kg of berries or fruit gives water activity of 0.97. A sugar content of 1 kg per kg of berries or stewed fruit gives water activity of 0.92.

Combined with boiling, this sugar quantity can prevent the growth of mould.