
Redcurrants are small, translucent, tart red berries borne in clusters.
Press them gently and strain: the skins split at once, and hard muddling pushes the seeds into the drink. They bring sharp acidity and a clear red. The red is pH-sensitive, so it holds in a sour drink and pales as dilution raises the pH.
Frozen redcurrants
Use the same amount, thawed first so they crush easily. One berry weighs 0.4–0.8 g, so a counted measure is better converted to weight.
White currant
Works as well, with a paler result.
Raspberry
Use the same weight. The color stays red, the taste softer.
Blackcurrant
Use the same amount for a darker drink that tastes of cassis rather than bright red fruit.
Cranberry
Raw berries barely crush, and the drink will want more sweetening.
A few days refrigerated, unwashed, in the container they came in, since washing early makes them collapse. They freeze well on the stem and thaw soft, which is fine for pressing and no good for garnish.