Rescues · TO INFUSE
Bitter and astringent.
Why it happens
Steeped too long or too hot. Tannins come out after the aromatics, so the extra time only adds harshness.
Recovering it
An over-extracted bitter infusion can be diluted, which costs strength but is better than the bitterness. A weak one can simply be steeped further, or the aromatics replaced with a fresh batch. If the flavour vanished to evaporation, add fresh aromatics off the heat and let residual warmth do the work — this recovers most of it and takes minutes.
The mechanism
Which liquid you infuse into decides what you extract, because flavour compounds divide into water-soluble and fat-soluble and the two do not swap. Water pulls out acids, sugars and some volatile aromatics; fat pulls out the terpenes and capsaicinoids that water leaves behind, which is why chilli heat blooms in oil and not in stock, and why milk infused with vanilla tastes of something water never gets. Heat speeds diffusion but also drives volatiles off, so there is a real tension: a hot infusion is faster and loses top notes, a cold one is slow and keeps them. That is the whole difference between hot and cold brew coffee. Time matters in the other direction too — tannins and bitter compounds extract more slowly than aromatics, so over-steeping does not add more of what you want, it adds what you do not.
The full TO INFUSE lesson — how to tell, where to practise it, what it carries to.