Freeze-dried sour cherries are the type used in black forest gateau. These taste like the original fruit and can be eaten straight away in their dry form, or they can be soaked in water to "plump" and soften.
Freeze-dried fruit is additive-free and contains no sugar or any other ingredients. They are the healthy option.
100g of freeze-dried sour cherries is the equivalent of 600g of sour cherries - Just the water is taken away. To reconstitute, use 5 parts water to 1 part fruit.
These are also perfectly edible in their dried form and are just like the crispy/crunchy pieces of fruit often found in pre-packed breakfast cereal (and you can be safe in the knowledge that these fruit pieces are just 100% fruit with no additives at all!)