The best-known of all freshwater fish, trout is also one of the most popular. It is inexpensive to buy and readily available, which makes it the perfect ingredient for a variety of meals. Trout doesn’t just taste fabulous, it has very high levels of omega-fatty acids, is low in fat and high in protein, so it is nutritionally good for you too.

The story of trout

Ever since man first learned to catch trout, these fish have been invaluable as a source of food. Native Americans, ancient Britons and early Europeans all treasured these tasty fish, and it is no surprise that the fish hook was one of man’s earliest tools. Fishing rods were in use around four thousand years ago and it is known that the ancient Macedonians were adept at fly fishing for trout. They used the technique known as dapping, which involves dropping the artificial fly lightly on the surface of the water so that the fish thinks it is the real thing and takes the bait. In a bid to increase the freshwater trout population, the ancient Chinese encouraged the fish to spawn on mats placed in rivers. The mats were then lifted out and the fertilized eggs were used to stock new breeding sites. The first person to artificially fertilize trout eggs is said to have been a French monk. The eggs were tightly packed in wooden boxes and buried in sand underground until they hatched.

Range and habitat

Like salmon, to which they are related, trout are native to the northern hemisphere, but they are also highly successful emigrants.

Brown trout are native to Europe, but they thrive in America. Conversely, the American rainbow trout has been successfully introduced to many other parts of the world. In New Zealand, for instance, the rainbow trout has acclimatized so successfully that many inhabitants of that country believe it to be one of their own native species.

Life cycle

There are many similarities between trout and salmon and both spawn in gravel pits, or redds, in fresh water. The young trout hatch after about 30 days. Initially they remain hidden in the gravel, feeding off their yolk sacs, but when this supply of food is exhausted they emerge. At this stage they are known as fry. As they grow, they develop markings, like fingerprints, on the sides of their bodies, and are described as parr, the name deriving from an Old English word for finger. Like young salmon, trout remain in their home waters for an initial period before swimming further afield to feed. Unlike salmon, however, most trout are fairly modest in their aspirations, moving to a larger river or lake rather than the ocean, although some species have adapted to living in salt water as well as fresh. Sea trout, cutthroat trout and steelhead rainbow trout are in this category. When they are several years old, the skins of these anadromous (i.e. migratory) fish become silvery and they are then known as smolts. They spend most of their lives at sea, only returning to fresh water to spawn. When and where individual species spawn depends on the variety of trout, the water temperature and other local conditions.

Trout eggs hatch earlier than those of salmon, giving the fry time to establish themselves before their larger relatives appear on the scene. There is considerable size variation between trout of different species and within the species themselves. The average rainbow trout on sale at the fishmongers weighs around 350g/12oz but fishermen have reported catching fish in excess of 12kg/26lb. Sea trout that evade capture can survive for many years and grow to over 40kg/88lb, although most fish sold commercially weigh about 3kg/6½lb.

Farming trout

Trout have been raised in captivity since the 1850s, initially with the aim of re-stocking freshwater rivers and lakes, but more recently for supply to the consumer. In the early years of the 20th century, a Danish trout farmer developed a system for introducing a flow of fresh water into his fish ponds to imitate river conditions. This helped reduce disease and led to improved yields. The first commercial fish farm in England was opened in 1950 and there are now more than 300 farms in the United Kingdom alone. Most farmed trout in the United States comes from Idaho and is considered one of the healthiest fish to eat by the Monterey Bay Aquarium’s Seafood Watch.

As with salmon, it is very important to buy farmed trout from a responsible producer who cares for the environment as well as for his or her fish. Some agrochemical farmers pollute rivers with pesticides, waste fish food and sewage. The trout are packed into pens, and this makes them vulnerable to disease and infestation by fish lice. In the wild, trout flesh is often pale pink, due to its natural diet. Some producers of farmed fish add colorants to the feed to mimic this. Organically farmed trout have creamy white flesh.


This is an excerpt from The Trout Cookbook by Jane Bamforth, RRP £10, published by Lorenz Books

ISBN 9780754834274