Dry-aging enables me to enhance the unique flavor profile and texture of fish species in addition to allowing fish to be maintained in premium condition for longer.
To appreciate what good fish tastes like, it must start with adjusting the way you handle fish (see Fish Butchery Basics), then tasting the fish in its purest form, untouched by water. Eating fish raw will help you understand the texture of fish to determine if it is soft or firm and if the flesh is fatty or lean. As well as eating raw fish, I find poaching fish gives you an insight into what the floor of the fish is really like. This, in turn, allows you to pick a suitable accompaniment for the fish that compliments, rather than complicates.
1. A fish with a firm mucus covering and shining coating is the first sign of a good-quality fish.
The mucus basically provides protection to the fish in the open ocean by trapping pathogens that would cause disease. Antibodies and enzymes in the mucus actively attach those pathogens to protect the fish. When and old mucus layer containing the pathogens is shed, it is replaced by new mucus and the pathogens are lost. Any visual damage or imperfections on a fish can suggest poor handling, prolonged direct ice contact or variable temperature control.
2. The eyes of a fish are a determining factor of a health, fresh fish.
A fish's eyes should look bulbous, be risen slightly from the head and look moist, bright and clear. There are, however, times when a fish that looks spectacular in every other way can have cloudy, slightly foggy eyes. This is predominantly due to the fish being chilled too quickly post-harvest.
Note: if you see a fish at the market with eyes that protrude considerably from the head, rest assured there is nothing wrong with it. This is and example of barotrauma, where a deep-sea fish has been caught at great depths and the large change in pressure caused by it being brought to the surface causes the eyes (and often also the stomach) to become more visually prominent than other species.
3. A fresh fish should not smell fishy.
The only smells a fish should have are a light ocean water smell sometimes comparable to mineral driven aromas, such s cucumber or parsley stems.
4. Iridescent bright red gills are an almost guaranteed indicator of the freshness of a fish.
5. If your fish is frozen, look for freezer burn or crystals.
If you see them it means the fish has been thawed and refrozen, which affects quality. Overall, in terms of flavor and texture, fresh farm-raised fish is often preferable if a wild-caught product is unavailable and frozen is the only option. But if you decide to go with frozen fish, just know that some fish types do better in the freezer than others -- lean white varieties, such as snapper and cod, tend to become dry when frozen, but the fattier types, such as tuna and Spanish mackerel, should be fine even when frozen.
'Fresh is best' seems to be the most overused statement when it comes to fish. The truth is, the reason that most people enjoy eating fish straight off the back of a boat is because it pretty much tastes of nothing.
Very similar to a just-slaughtered cow, a freshly caught fish carries very little to no aroma or flavor. Dry-age that cow, however, and you enhance both its taste and consistency by reducing moisture and breaking down the enzymes within the animal protein. The same is tru of dry-aged fish: though the desire here is not to break down any connective tissues as it is for meat but to reduce the level of unnecessary moisture present within the fish to heighten its flavor. Much like aging beef, the aging process for fish requires the same controlled environment where the temperature and humidity levels are carefully monitored.
保存鱼的要点：
Low temperature, preferably between -2 and 2°C (28-36°F).
Low humidity.
Prevention of 'sweating' from contact with surfaces: fish skin will sweat if let in contact with a surface for a lengthy period of time. Fish left sitting on a tray or plate will eventually create a pool of its own juices beneath it. These juices will speed up the deterioration process and create that 'fishy' smell. To prevent this, hang large fish from butcher's hooks in storage and store smaller fish and fillets on stainless-steel perforated trays.
Prevention of drying out.
最佳dry-age（熟成）时长取决于鱼肉的脂肪含量和肌肉组成：
high fat content + dense muscle composition --> lengthy dry-ageing. E.g. Spanish mackerel, tuna, and swordfish.
fish with slightly more open-textured profile --> may only need 4-5 days. E.g., john dory, bream, and flounder
fresh is best for delicate, whiting, herring and slimy mackerel.
