Ingredient

Apple cider

Unfiltered, unsweetened pressed apple juice — the American sense, not the alcoholic British one. Cloudy with pulp, more tannic and less sweet than clear juice, which is what lets it reduce into a glaze without turning to syrup.

Sourcing
Chilled, seasonally, in American shops; elsewhere cloudy pressed apple juice is the same product under another name. Not to be confused with cider vinegar or with hard cider.
Varieties
Fresh-pressed, Pasteurised, Spiced
Quality cues
Opaque brown-gold with sediment that settles out and shakes back in. Clear and pale means it has been filtered and sweetened.
Substitutions
Cloudy apple juice, Clear apple juice, with a squeeze of lemon
Storage
Refrigerate. It is unpasteurised in some markets and will begin to ferment within a week or two, which is not a fault but is a surprise.
Shelf life
1-2 weeks refrigerated