Steaming fish

I love seafood. Which would be a story in itself. I grew up with Southern German cuisine where there is no space for seafood. For many years of my childhood, eating fish for me meant having whitish cuboids with fishy flavour. I am talking of Fischstäbchen (fish fingers), Schlemmerfilet etc. Fortunately, things have changed. Nowadays, most of us have access to fresh seafood in all its diversity: fish, crustaceans, and molluscs. What a treat.

I’d like to talk a bit bout cooking fish. Cooking fish is not difficult, but there are a few things to consider. Fish muscles are slightly different from mammalian muscles (“meat”). The reason why we cook meat is its collagen content. Collagen is the major protein (more precisely, it is a protein family) of connective tissue. Connective tissue serves two purposes: It gives organs their form, and it holds them in place. Muscles consist of a bunch of muscle cells, which are surrounded by relatively loose endomysial and perimysial connective tissue (mainly type III collagen), the whole muscle itself is enveloped by a tight fascia (mainly type I collagen). The muscle is then attached to the bones by the very tough tendons (mainly type I collagen).

Collagen fibers consist of three subunits which are interconnected to a triple helix by numerous hydrogen bonds. This triple helix is extremely robust. Collagen-rich pieces of meat are, therefore, tough and practically inedible in the raw state. However, during cooking, the triple helix disintegrates and the collagen subunits separate. This is what makes the meat tender.

Fish, compared to meat, contains much less collagen. Most obvious is the lack of tendons. Instead, thin septa (myocommata) divide the muscle into short segments (myotomes) and insert at both the skeleton and the skin. Furthermore, the amino acid composition of fish collagen is slightly different from mammalian collagen. Its lesser hydroxyproline content leads to decreased binding forces between the three collagen subunits. Due to these two circumstances, fish will cook much faster than meat. And overcooking is much easier.

In my opinion, one of the best ways to cook a whole fish is steaming it. Steaming has been done in South East Asian cuisines for centuries, and this is why I’d like to present a Thai recipe to you. Steaming has two advantages. First, temperature will never be higher than 100 °C. Second, only few flavour components of the fish will be washed out since there is no direct contact to fluids. Steaming is also very simple and fool-proof. However, you do need some special equipment.

I use a wok and a bamboo basket for steaming. This is the traditional Asian way. I guess you can use a modern Western steamer as well, where your food is put on metal racks. I have never tried that. But there is one thing that you should NOT do. In some books and on several websites, you can read that you can put your fish on a simple plate which is then placed on a cup or a bowl to keep it above the boiling water. Believe me, you don’t want to do this. During steaming, the fish will lose some liquid, which has an unpleasant fishy flavour. It should drain immediately instead of soaking the delicate fish.

The result of steaming is an amazingly pure and natural tasting fish with a juicy and tender texture. Combining it with hot, sour, and sweet Thai flavours makes a sensational dish.

Thai steamed fish with lime chile sauce

Serves 1-2:
1 whole fish (about 500 g, e.g. bream, bass, or snapper)
1 large handful coriander leaves
100 ml lime juice
2 tbsp. minced red chile
2 tbsp. minced garlic
1 tbsp. minced coriander roots
2 tbsp. fish sauce
1 tbsp. light soy sauce
1 tsp. sugar

Rinse the cleaned and gutted fish under cold water and dry well with paper towels. Lay three or four coriander sprigs in a bamboo basket and put the fish on top. Cover the bamboo basket with its lid.

Pour about 5 cm of water into a wok and bring to boil. Place the basket over the water and steam the fish for about 10-15 minutes over low heat.

In the meantime, mix lime juice, chile, garlic, coriander roots, fish sauce, soy sauce, and sugar in a small pot. Bring to a short boil, then remove from the heat. Chop the remaining coriander leaves coarsely.

Transfer the cooked fish to a serving plate, pour with the sauce, and cover with the coriander leaves.