Work out cider tannin adjustment instantly with clear inputs, formula shown and shareable results.
Tannin at 0.15-0.25% w/v gives cider structure, astringency and colour stability. One percent w/v is 10 grams per litre, so the pure tannin required is volume times the deficit times ten, divided by the product's purity. Additions should be trialled at bench scale first because perception is highly non-linear.
Tannin addition
Pure tannin (g) = volume (L) x deficit (% w/v) x 10; product = pure / purity
Before or early in fermentation for structural tannin that integrates, or at maturation for a finishing adjustment. Late additions taste more aggressive and can drop out over time.
Yes, with gelatin, PVPP or egg white fining, but these also strip aroma and colour. Blending with a low-tannin cider is usually gentler.