Blueberry Sour Cream Mousse

If the frozen berries are very hard, let them thaw for 5 minutes - they will be easier to blend.

Add the lemon juice little by little and taste as you go - depending on the berries' tartness it can be milder or more tangy.

Whip the cream only to soft peaks, not too firm - this keeps the mousse especially delicate.

For clean layers, put the mousse into a piping bag (or a freezer bag with the corner snipped off).

You can also chill the glasses for 20-30 minutes - the mousse will firm up slightly and the flavors will meld.