Ingredient

Blackberry

Picked ripe they do not travel or keep, which is why supermarket blackberries are so often sour — they are harvested underripe to survive the journey. A blackberry ripens on the bush and not after.

Sourcing
Foraged in late summer, or from a farm shop. Frozen blackberries are a better buy than poor fresh ones for anything cooked.
Varieties
Wild, Loch Ness, Chester, Marionberry
Quality cues
Deep matte black and plump. Any red or purple drupelets mean underripe and sour; a shiny berry is usually not ready.
Substitutions
Raspberry, Blueberry, Loganberry
Storage
Refrigerate unwashed in a single layer and wash just before use — they collapse fast once wet.
Shelf life
2-3 days refrigerated; 12 months frozen
Nutrition

Per 100 g

Calories
43 kcal
Protein
1.4 g
Fat
0.5 g
Carbs
9.6 g
Fibre
5.3 g
Sugars
4.9 g
Sodium
1 mg

From USDA FoodData Central (#173946). Raw, edible portion.