Cream-filled chocolate desserts like truffles and ganache need to go in the fridge, in a closed container, unlike a plain chocolate bar; the cream or butter inside softens quickly at room temperature and the shape falls apart.
Kept covered in the fridge, truffles hold their shape and texture for about a week. Pulling them out roughly half an hour before serving lets the flavor come through more clearly.
Why does ganache turn runny at room temperature?
Ganache is chocolate melted into hot cream, and its fat content softens easily once it warms up. A cake coating made from it will start sliding if left in a warm kitchen; keeping it covered in the fridge avoids that.
Ganache or truffles moved to the freezer, tightly wrapped, keep for roughly two months; thawing them in the fridge rather than on the counter cuts down on surface sweating.
What mistakes ruin the flavor?
The most common mistake is sealing warm truffles into a closed container and putting them straight in the fridge; the trapped steam condenses on the surface and ruins the texture. Letting them cool a few minutes at room temperature first gives a better result.
Chocolate desserts stored next to strongly scented food can pick up an off flavor within a day or two, since chocolate absorbs odors easily; keeping them in their own tightly sealed container in the fridge avoids that.
What matters before and after serving?
For a cake with truffles or ganache, pulling it out of the fridge at least twenty minutes before guests arrive, rather than right before serving, gives a more balanced texture; chocolate that's too cold doesn't show its full flavor or texture.
When leftover truffles go back in the fridge, handling them with a clean fork or tongs instead of fingers keeps oil and moisture from the skin off the surface, which can otherwise speed up spoilage.
Short trips at room temperature aren't a problem for chocolate desserts being given as a gift, but for anything lasting several hours, using a cooler bag keeps the dessert from losing its shape along the way.
Truffles dusted with cocoa powder or coconut are worth remembering can turn sticky in a closed container as that coating absorbs moisture; laying them out in a single layer rather than stacked keeps the coating from smearing.
For a ganache cake being delivered on a hot summer day, tucking an ice pack into the box for the trip largely keeps the chocolate from losing its shape along the way.
A truffle recipe with a higher ratio of dark chocolate holds up a bit better at room temperature than one made mostly with milk chocolate, which makes a dark-chocolate-heavy recipe the smarter choice for desserts left out on a long party table.
Hands warm up chocolate quickly while shaping truffles, so rinsing your hands in cold water for a minute beforehand slightly slows how fast the chocolate softens while you work.
A thin film of moisture can appear on ganache fresh from the fridge; that's just condensation as the container moves from cold to warm air, and it can be gently wiped off with a paper towel before serving.