In short: Freeze-drying removes moisture from fruit in a vacuum. The berry loses its water but keeps its flavour, colour and vitamins, which is why it goes into chocolate, creams and decoration where fresh fruit would add unwanted moisture.
How freeze-drying works
The berries are frozen first, then the moisture is removed under vacuum. Because the fruit is never heated, the process preserves the vitamins, the minerals and the natural flavour — which is precisely what makes freeze-dried fruit such a useful pastry ingredient.
This is the key difference from ordinary drying, where heat drives off both water and a good part of the aroma and colour along with it.
Where they are used
Anywhere fresh fruit would ruin the texture. Whole or in pieces they go into chocolate bars and bonbons; ground to powder they colour and flavour creams, ganaches and macaron shells; broken into shards they finish a cake without weeping into the coating.
How to store them
In an airtight container with no access to air. Freeze-dried fruit absorbs moisture almost instantly and clumps together — an opened bag left on the counter is usually ruined by the next day.
Frequently asked questions
How do freeze-dried berries differ from dried ones
Drying uses heat, so part of the flavour and colour is lost. Freeze-drying uses none, and both stay close to the fresh fruit.
Can freeze-dried berries go into chocolate
Yes, that is their main use: they contain almost no water, so the chocolate will not seize.
How should they be stored
Airtight, away from air and humidity. They take up moisture immediately and stick together.