I use the smaller of the two sizes of Costa gelatine, as these seem most readily available.
Prep time: 30 minutes, plus setting time | Cooking time: 10 minutes
For the buttermilk layer
3 small leaves gelatine
125ml double cream
35g caster sugar
For the blackberry layer
7 small leaves gelatine
285ml red wine
50ml crème de cassis or crème de Mûre
135g granulated sugar
strip of lemon peel
125g blackberries (plus extra for serving – optional)
For the buttermilk layer, put the gelatine in a bowl of cold water for five minutes to soften.
Bring the cream, milk and sugar to just under the boil, stirring to dissolve the sugar. Remove from the heat and leave to cool to hand-hot.
Gently squeeze the gelatine, add to the cream and stir. Whisk in the buttermilk.
Divide between eight glasses and set in the fridge for three to four hours, or overnight.
For the jelly, put the gelatine in a bowl of cold water for five minutes.
Heat the wine, crème de cassis, 125ml water and the sugar with the lemon peel, stirring gently to dissolve the sugar. The wine shouldn’t become hotter than hand warm.
Gently squeeze the gelatine, add it to the wine and stir to dissolve. Leave to cool – not so long that it starts to set. Divide the blackberries between the glasses, pour on the jelly, then return to the fridge to set.
You can put more blackberries on top if you want. Remove from the fridge a while before serving them so that they are not fridge-cold.