Deep frying

How to tell it is going right

• The oil was at temperature before anything went in, measured rather than guessed, and the vessel is no more than two-thirds full.
• Everything went in dry. Surfaces are patted down and any coating is not dripping, because water hitting hot oil erupts and is the one accident this technique actually has.
• The oil recovers between batches. It is back at temperature before the next load goes in rather than falling further with each one.
• A steady vigorous bubbling that slows as it finishes: the bubbles are the food’s own water leaving, so a piece that has gone quiet has stopped drying out and is done.
• Seasoned or finished in the first seconds out of the oil, while the surface is still hot and will hold what lands on it. Anything applied to a cooled crust sits on top and falls off.

Where it goes wrong Too much went in at once and the oil temperature collapsed. The crust forms slowly while the food sits in warm fat absorbing it rather than shedding steam, and it comes out heavy and greasy instead of crisp, which no amount of draining afterwards will fix.