Rainbow Trout vs Brown Trout – The Trout Differences

There are many different types of trout including rainbow and brown trout. Some trout swim in the same water. For this reason many people wonder about their differences. Let’s answer the question, what is the difference between brown trout and rainbow trout?

Brown trout and rainbow trout are different species of fish although from the same family. While in similar water, rainbow trout grow slightly longer and weigh more than brown trout. Rainbow trout are more colorful than brown trout. Brown trout has a stronger, fishier taste than rainbow’s mild flavor.

This article will compare their tastes, textures, cooking methods, costs, mercury levels and whether one can substitute for the other in recipes. In addition, I’ll do a side-by-side comparison of their nutrients, habitats, size, weight and more.

Rainbow Trout vs Brown Trout: Habitats, Size, Weight, Appearance

What is the difference between the two trout?

The average rainbow trout is longer and weighs more than brown trout located in the smaller waters. Rainbow trout has more color with olive to dark blue and silver coloring while brown trout is brown and olive-green with golden sides. Rainbow trout’s lifespan averages 7 years compared to 5-10 years for brown trout.

Scientific Classifications, Families, Species

Rainbow trout are from:

• The salmonidae family
• Oncorhynchus genus
• The species O. mykiss.

Brown trout are from:

• The salmonidae family
• Salmo genus
• The S. trutta species

Habitats

• Rainbow trout are native to North America and found in tributaries (rivers and streams) or lakes in North America. Some of the rivers and streams where they’re found flow into larger rivers or streams but not into the ocean.
• Brown trout are found in rivers, ponds or lakes in North and South America, Europe, Asia and Africa. The first ones were imported to the United States from Germany in 1883.

Both trout are hatched in freshwater streams, rivers and lakes. Steelhead and rainbow start their lives the same way. Rainbow trout remain in the freshwaters and never leave. After 1-3 years the steelhead trout start migrating to the sea.

Rainbow trout were introduced to the Great Lakes in 1895. They are not native to the lakes. They grow larger than the rainbows native to the streams and rivers. For this reason some people will call them steelheads.

Colors

• On the back the rainbow trout’s colors range from brown to olive to dark blue. The sides are silvery to pearl white. They have a pinkish to red lateral line from the gills down. The body has black spots.
• Brown trout are brown to an olive green near the top. The sides are a creamy, golden and off white on the belly. They are covered in black and golden, brown spots.

Appearance

• Both trout have a very similar body shape. They have the typical long, narrow body shape and two dorsal fins.

Size and Weight

• Rainbow trout grows an average 11-18″ in length and weighs 2-8 pounds.
• Brown trout in smaller rivers and streams average 7-14 inches long and 2 pounds. In the larger waters they are longer and heavier.

Age

• Rainbow trout averages 7 years but the maximum known age is 11 years.
• Brown trout’s age varies from habitat to habitat. In smaller waters they average 5 years and up to 10 years in larger bodies of water.

Diets

Brown trout consumes the following diet:

• Insects
• Crayfish
• Salamanders
• Frogs
• Mollusks
• Small fish

Rainbow trout consumes the following diet:

• Crustaceans
• Mollusks
• Gobies
• Fish eggs
• Nymphs
• Sunfish
• Shiners
• Minnows
• Insects

Trout Fishing

The trout fishing season may vary depending on your State. Some have brown trout fishing all year in lakes and ponds and in inland streams from April to October.

Always check your required local fishing rules and regulations. Prior planning and research will lead to a more successful fishing trip.

In many places late spring is the best time. As the temperatures warm up competition from other anglers increases.

Trout are more active between 34 and 67 degrees. In the 40s feeding increases. Under cloud cover and shady areas may be better.

Different trout species like lake trout, river trout, brook trout, rainbow trout, cutthroat trout may have different rules, gear, rod, fishing line, fly tying and fly fishing tips.

Species Resources¹ (National Park Service: Brown Trout)) 

Trout Tastes and Texture

One of the most important things people takes into consideration when choosing a fish or while fishing is its taste. Let’s compare the taste of the two fish, rainbow trout vs brown trout.

Brown trout has a stronger and fishier flavor than rainbow trout. Rainbow trout often have a very mild taste and does not taste fishy. If a fishy taste is desired brown trout is better. If a fishy flavor is undesirable then rainbow trout is better. Both fish have a tender, flaky texture.

Rainbow trout is often described as a slightly nutty flavor. It’s texture is delicate, soft and flaky when cooked.

Brown trout has a stronger, fishier taste. The larger the fish was when caught, the more fishy taste the fillet will contain. The texture is delicate and flaky when cooked.

Many people soak trout in milk overnight. This helps remove some of the fishiness by drawing out some of oil.

I conducted original research on trout taste by polling readers, my clients and people in food groups. I asked which taste they preferred better?

• 61% preferred rainbow trout.
• 39% preferred brown trout.

I conducted more research by setting up a blind taste test at my home. Both fish were cooked and seasoned the same way. Three out of four people chose the rainbow.

If you’re wondering how steelhead trout differs, check out my article, Steelhead Trout – What’s The Difference?

Substitutions

When preparing recipes for dinner it’s not always possible to locate the type of fish in the market or while fishing. If you have only one trout, you may wonder if you can substitute one trout for the other.

Rainbow trout can substitute for brown trout due to their similar textures although brown trout’s flavor is fishier and more oily. Both trout have a similar texture allowing for similar cooking methods in recipes. Both trout can be grilled baked, roasted, poached, fried or seared. 

The best brown trout substitutes include the following:

• Rainbow trout
• Salmon
• Swordfish
• Tuna
• Northern pike
• Mackerel
• Herring
• Bass

The best rainbow trout substitutes are:

• Salmon
• Arctic char
• Bluefish
• Steelhead trout
• Mahi mahi
• Mackerel

When substituting either trout attempt to stick to the following:

• Same size and weight.
• Stick with similar fillets, whole fillet or cross section.
• Stick with skinless or skin when the recipe calls for one.
• Texture is more important for certain cooking methods. Like using a firmer texture when grilling².

How To Cook Rainbow Trout

Rainbow trout can be cooked in a variety of ways. Any way that you could cook chicken will probably work on trout too. To be safe to eat, fish needs to be heated to at least 145 degrees, so keep that in mind when choosing cooking times and temperatures.

Flavor Pairing

Cooking up your trout without any seasonings will result in a rather bland-tasting meal. You’ll want to marinate or cook your trout in some tasty oils, seasonings, and sauces to get the best flavor out of this popular fish.

Each type of fish has a slightly different flavor and therefore tastes best when paired with certain spices. Some common good seasonings to add to your trout are:

• Lemon
• Dill
• Garlic
• Butter
• Scallions
• Rosemary

Because of its mild flavor, using strong or citrus flavors is a good idea. The intense flavors of your seasonings complement them and add to the taste of the trout.

How To Cook Brown Trout

Some chefs suggest frying brown trout in a beer batter. Others like to bake it wrapped in foil with some potatoes, onion or garlic. The stronger flavor doesn’t require heavy seasoning like some other white fish.

To lessen the fishy taste soak the trout in milk overnight to draw out some of the oil.

Flavor Pairing

• Citrus
• Smoked paprika
• Garlic
• Chile powder
• Barbecue sauce
• Lemon juice

Check out the best replacements for trout in my article, Trout Replacements: The 12 Best Healthy Substitutes.

Cost

The costs for certain fish will vary depending on how the fish are caught fishing and the location it is sold.  A wild caught will definitely be more expensive than farm-raised.

When purchasing fish, be sure to check the label. Let’s take a close look at the prices of each one.

Brown trout cost more than rainbow trout. The average cost for rainbow trout online is $16.00 per pound while the average cost for brown trout is $28.32 per pound. Live brown trout for stocking cost $10.00 per pound and rainbow $8.00 per pound.

Brown trout are much less plentiful than their cousins in the stores. I conducted original research on costs by visiting various different stores and checking their prices.

First, I checked online at the Fulton Fish Market and found the following prices:

• Previous frozen brown trout fillet
  • $28.32 per pound
• Rainbow trout fillet
  • $16.00 per pound

I checked the local Freshdirect online supermarket for the current prices but only found rainbow.

• Wild rainbow trout butterflied
  • $11.99 per pound

I then checked my local Shoprite supermarket and only found one trout:

• Fresh, farm raised rainbow trout fillet
  • $9.99 per pound

Online I checked the prices of live trout for fish stocking.

• $8.00 per pound for Rainbow trout
• $10.00 per pound for brown trout

Brown Trout vs Rainbow Trout Mercury Levels

The EPA and FDA have issued warnings and suggestions regarding mercury levels in fish and how often they should be consumed³. This is especially important for young infants, developing children and pregnant women.

They established a list of best fish, good choices and ones to avoid based on their mercury levels. Let’s examine the mercury levels found in trout.

Rainbow trout and brown trout have similar levels of mercury. Freshwater trout are listed on the FDA’s best choices of fish to consume regarding their mercury levels.

Always check with a physician prior to eating new foods or changing your dietary habits.

Rainbow Trout and Brown Trout Nutritional Value

The following table is a side-by-side comparison of all the nutrients per four ounces:

Nutrient	Brown Trout, raw (4 Ounces)	Rainbow Trout, raw (4 Ounces)
Calories	168	135
Fat	3.4 g	3.9 g
Saturated Fat	1.6 g	0.8 g
Cholesterol	66 mg	67 mg
Protein	21 g	23 g
Sodium	61 mg	35 mg
Omega-3	1.04 g	0.79 g
B-6	0.2 mg	0.4 mg
B-12	8.8 mcg	5.0 mcg
Thiamin	0.39 mg	0.13 mg
Riboflavin	0.37 mg	0.11 mg
B5	2.2 mg	1.0 mg
Iron	1.7 mg	0.7 mg
Niacin	5.1 mg	6.1 mg
Folate	14.7 mcg	13.6 mcg
Potassium	441 mg	545 mg
Magnesium	32 mg	35 mg
Phosphorus	277 mg	307 mg
Calcium	48.7 mg	75.9 mg
Zinc	0.7 mg	1.2 mg
Selenium	15.0 mcg	14.3 mcg

Nutrient Sources⁴⁵⁶

Both fish contain a good number of minerals and vitamins. At first glance it’s difficult to determine which fish provides more. Let’s take a close look at which one is healthier.

Brown trout is healthier than rainbow trout due to its higher percentage of heart healthy omega-3 fatty acids and B vitamins. It provides more B12, thiamin, riboflavin, B5, folate and selenium. It also contains less cholesterol and total fat than rainbow trout.

Rainbow trout is healthy and provides a good number of omega-3 fatty acids and minerals. It provides a higher percentage of B6, niacin, potassium, magnesium, phosphorus, calcium and zinc.

It difficult to argue against either trout for their health benefits. The major difference between the two is the omega-3 fatty acids. If you’re wondering why they’re so important, keep reading the next section.

Rainbow Trout and Brown Trout Health Benefits

Both fish provide the same nutrients and therefore the same benefits. Although I broke down the benefits by which fish offers the higher percentage of each nutrient ((FDA: Seafood Nutrition Facts)).

Brown Trout Health Benefits

Omega 3 Fatty Acids

Brown trout provides 1.04 grams per four ounces raw. They contain approximately 32% more which leads to the question, why does omega-3 fatty acids matter so much?

It’s because omega-3 fatty acids are heart healthy and help keep arteries healthy. The omega-3s in brown trout may help with the following:

• Keeping bad cholesterol low.
• Keeping good cholesterol high.
• Reducing inflammation.
• Reducing plaque build-up.
• Lowering triglycerides
• Help keep the heart rhythms more normal.

DHA and EPA, two of the fatty acids, are associated with lowering blood pressure and improving the health of blood vessels ((National Center for Biotechnology: Marine Omega-3 Supplementation and Cardiovascular Disease)).

Studies suggest omega-3s can help reduce joint pain and stiffness in people with rheumatoid arthritis. They may also boost the effectiveness of anti-inflammatory drugs.

B Vitamins

Of the seven B vitamins listed in the table above, brown trout contains more of five of them. The B vitamins in the table include B6, B12, B5, B1 (thiamin), B2 (riboflavin), B3 (niacin) and B9 (folate). B vitamins help support the following:

• Cardiovascular disease
• Red blood cells
• Digestion
• Energy levels
• Brain function
• Nerve function

Selenium

Selenium is an underreported nutrient. I’m unsure why many don’t write about it more because studies⁷ show selenium may help to protect the following:

• Heart disease
• Thyroid
• The immune system
• Cognitive issues

Rainbow Trout Health Benefits

Calcium

Rainbow trout provides 75.9 mg of calcium per four ounces. Calcium is important for blood pressure and the heart.

Harvard Health reports calcium helps maintain blood pressure because it helps to control the relaxing and tightening of blood vessels⁸. Calcium also helps the following:

• Build and maintain strong bones.
• Muscles need calcium to function properly.
• Improve nerve function.

Potassium

Since the recommended daily amount is 4,700 mg, both trout provide an excellent number.

Potassium is beneficial for reducing sodium intake. It helps the body reduce fluids and rids excess sodium ((American Heart Association: How Potassium Can Help Control High Blood Pressure)). This process helps to reduce blood pressure.

The more potassium you consume, the more sodium your body will lose. Consuming too much sodium or not enough potassium throws off the delicate balance the kidneys need to remove the excess water⁹.

According to Harvard Health, a number of studies have shown a connection between low potassium levels and increased blood pressure¹⁰.

Magnesium

Adding magnesium to your diet could be instrumental in improving sleep related issues like insomnia. Magnesium relaxes and calms the whole body including the blood vessels ((National Institutes of Health: Magnesium)).

More so, it helps keep blood pressure levels balanced and stable. A recent study researched 22 studies and concluded magnesium supplementation decreased diastolic and systolic blood pressure¹¹.

Magnesium in trout helps control muscle and nerve function, blood sugar and blood pressure. In the muscles and heart, magnesium competes with calcium to help the muscles relax after contracting.

When the body is low in magnesium, calcium can over stimulate the heart muscle’s cells causing a rapid or irregular heartbeat.

Phosphorus

Phosphorus has been shown in studies to may help the following:

• Muscle contraction.
• Muscle recovery after exercise.
• Promoting healthy nerve conduction.
• Promote bone and teeth strength.
• Aids the kidneys in waste removal.
• Help the body manage and store energy.

Find out how trout compared to bass in my recent article, Trout vs Bass – What’s The Difference? Let’s Compare.

Species Resources¹ (National Park Service: Brown Trout)) 

As a Certified Health Coach, many of my clients ask me about seafood. In addition to coaching clients about brown and rainbow trout, I’ve purchased, researched and consumed both fish for over 20 years.

If you have any questions about this article or other featured content, don’t hesitate to email and notify us. You can find an email on our contact page. We’ll do our best to reply as soon as possible.

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Read Next – More Trout vs Fish Articles!

Rainbow Trout vs Salmon: Is One Better?

Trout vs Salmon: Is One More Healthier Than The Other?

Steelhead vs Salmon: Which Is Better?

Rainbow Trout vs Cod: Which Is Better? Let’s Compare

Cod vs Salmon: Is One Better?

1. U.S. Fish and Wildlife Service: Rainbow Trout [↩] [↩]
2. Sea Grant North Carolina: Fish Flavors and Substitutions [↩]
3. FDA: Advice about Eating Fish [↩]
4. New Zealand Food Composition Data: Trout, brown, flash, raw [↩]
5. Nutrition Value: Fish, raw, wild, rainbow, trout [↩]
6. USDA: Trout [↩]
7. National Institutes of Health: Selenium [↩]
8. Harvard Health: Key minerals to help control blood pressure [↩]
9. National Center for Biotechnology Information: The Effect of the Sodium to Potassium Ratio on Hypertension Prevalence: A Propensity Score Matching Approach [↩]
10. Harvard Health: Potassium lowers blood pressure [↩]
11. National Center for Biotechnology Information: Effect of magnesium supplementation on blood pressure: a meta-analysis [↩]