Alder is the gold standard for smoking fish

Alder.

That is the short answer. If you smoke fish and you are not using alder, you are probably making it too aggressive.

Fish is delicate. It takes smoke fast and holds onto it. Strong woods like hickory or mesquite turn it into something that tastes like a campfire ate a fish. Alder is the classic Pacific Northwest choice for salmon, trout, and most white fish. It gives a mild, slightly sweet smoke that lets the fish taste like itself.

Apple and cherry are also good. They are fruitwoods, gentle, with a hint of sweetness. Maple works too, but can be a little too subtle. If you want to get fancy, try a mix of alder and apple.

On a gas grill, you need to make a smoker pouch. Soak the chips for 30 minutes, drain, wrap in heavy-duty foil with a few holes poked in the top, and set it directly on the burner. Keep the temperature low — 200-250°F — and indirect heat. Fish does not need hours; thin fillets can be done in 30-45 minutes.

So: alder. If you cannot find it, apple. Do not use mesquite unless you hate fish.