Oily fish against oak — flavouring profile

The most common serious clash in food and wine, and the most severe: an oaked white does not merely sit awkwardly with oily fish, it turns the mouthful metallic.

The compounds that matter. Trimethylamine is the one that does the damage. It builds in fish flesh after the catch, and it is far higher in the oily fish — salmon, tuna, mackerel, sardines, anchovies, herring — than in white fish, higher again in anything cured, salted or smoked, and higher still the longer the fish has been out of the water. It reacts with the tannins and aldehydes that oak leaves in a wine to produce a distinctly metallic, intensified-fishy taste. This is chemistry rather than a matter of preference: it happens to everyone, and it is present whatever else is going on with the dish. Alongside it sit the omega-3 oils, which coat the palate and need acidity to clear, and in cured versions a heavy salt load that flattens a soft wine.

What it demands of a wine. No oak. That is the whole of the first rule and it admits almost no exceptions. Then high acidity to cut the oil, and enough salinity or mineral grip to meet fish that is often served with lemon, vinegar or salt. Body should match the preparation rather than the fish: raw tuna wants something light and precise, grilled mackerel something with more weight.

One real exception. Heavy char changes the terms. Fish grilled hard enough to carry genuine browning and smoke can take a subtly oaked white, because the char balances the oak vanilla instead of fighting it. It is a narrow exception and it needs real char, not a griddle mark.

Seek

Unoaked, high-acid whites, and the leaner and more saline the better: Muscadet from the Loire, Albarino from the Atlantic coast, Assyrtiko from Santorini, Picpoul, Verdicchio, Vermentino. For smoked and cured fish, dry Riesling is the specialist answer, because bottle age gives it the weight to ride over smoke without any oak involved. For salted and cured versions, anchovies and boquerones above all, Fino Sherry has both the salinity and the savoury weight to meet them, where the lighter Manzanilla would disappear. Sparkling works wherever the fish is fried. Where a red is wanted, only the palest and lowest in tannin will do, served cool.

Avoid

Every oaked white, which is the point of this entry: the barrel-fermented Chardonnay that looks like the obvious grand choice is the single worst thing to pour. Tannic reds, for the same metallic reason. Anything soft or low in acid, which the oil will flatten.

Three to reach for. A Muscadet from the Loire for almost anything, and the cheapest of the three. A Fino Sherry from Jerez for cured and salted fish, where nothing else comes close. A dry Riesling for smoked fish, where a little bottle age carries the smoke.