Redcurrant

The jelly is a sauce that is only acid and sugar, which is all lamb fat needs.

Cumberland logic: sharp red fruit against iron, with port doing the joining.

Sourness this high is not a flavour until sugar gives it something to sit on.

Fortified sweetness plus screaming acid. Neither is drinkable alone at this ratio.

Zest oil rounds the sourness off at the top without diluting it.

One brings perfume, one brings pectin and acid. Summer pudding runs on this.

The fattiest bird on the table needs the sharpest thing in the larder.

Resin gives a purely sour fruit the woody bottom end it is missing.

Sharp red fruit does the acid and the sugar in one addition, late in the pot.

Sour on sour, but the fat length makes the acid land later and softer.

Oily fish and a sour berry: the northern European answer to gooseberry sauce.

Citrus tingle over pure acid. The mouth cannot tell which is doing the work.