Sour cherries spoil very quickly: If its is rainy, they burst and get mouldy.
* Left: This can be avoided, by transferring them into a concentrated sugar solution.
Observation:  The cherries lose water very quickly but they keep like this.
Explanation:  The changes of cherries in water and in sugar solution are similar to those observed with
potatoes in water and in salt water
* In fresh water water is soaked up by the tissues: The volumes of potato and the cherry increases.
* Concentrated solutions of sugar or salt suck water out of the tissues: The volumes decrease.
Remember: Food can be made non-perishable by adding big quantities of sugar or of salt.
                       Fungi and bacteria cannot grow because they are deprived from water.