Buttermilk is a popular ingredient used in many recipes, including for preparing fish. Some cooks swear by soaking fish in buttermilk before cooking to help tenderize it and add flavor. But is this step really necessary? Here is a comprehensive look at the pros and cons of soaking fish in buttermilk.
What is Buttermilk?
Buttermilk is a dairy product formed when cream is churned into butter. The liquid left behind after the butter is removed is buttermilk. It has a tangy, acidic taste and thick texture.
Traditionally, buttermilk was the leftover liquid from churning butter from cultured or fermented cream. This process gave buttermilk a lot of beneficial probiotics and a sharp, tangy flavor.
Nowadays, most commercial buttermilk is made by adding bacterial cultures to low-fat or skim milk. This gives it a thicker texture and tangy taste similar to traditional buttermilk.
Benefits of Soaking Fish in Buttermilk
There are a few reasons why cooks soak fish in buttermilk before cooking:
- Tenderizes the fish – The lactic acid in buttermilk helps break down tough proteins and connective tissues in fish. This can help make the fish more tender when cooked.
- Adds flavor – Buttermilk has a tangy flavor from lactic acid that can infuse into the fish. This can enhance the flavor of mild white fish especially.
- Retains moisture – The thickness of buttermilk can help fish retain moisture when cooked, preventing it from drying out.
- Adheres coatings – If you want to bread and fry fish, soaking it in buttermilk helps the coating adhere better and fry up extra crispy.
Does Soaking Really Make a Difference?
While there are some benefits to soaking fish in buttermilk, it’s debatable whether it makes a major difference compared to simply seasoning and cooking the fish.
Here are some things to consider:
- Fish tenderizes quickly with heat – Fish is very delicate and will become flaky and tender after just a few minutes of cooking. The tenderizing effect of buttermilk may be negligible.
- Mild flavor impact – The buttermilk flavor is subtle and often gets lost once other seasonings and ingredients are added.
- Breading adheres fine without soaking – You can dredge fish in flour or cornstarch then egg wash to get a very crispy coating without soaking in buttermilk first.
- Moisture depends more on cooking method – Gentle cooking methods like baking en papillote or poaching make fish moist. Frying or grilling over high heat will dry out fish regardless of a buttermilk soak.
While soaking in buttermilk doesn’t hurt fish, it may not make a major difference in the final cooked product. Proper seasoning and an appropriate cooking method may have a bigger impact.
How Long to Soak Fish in Buttermilk
If you do want to soak fish in buttermilk, the recommended time is 30 minutes to an hour. Any longer than that risks the fish becoming too denatured and soft.
Here are some soaking tips:
- 30-60 minutes is ideal for most fillets or steaks 1-2 inches thick.
- Thinner fillets or slices may only need 15-30 minutes.
- Whole small fish like sardines need just 10-15 minutes.
- Pat fish dry after soaking so coating adheres better.
- You can soak in buttermilk then refrigerate fish up to a day before cooking.
The Best Fish to Soak in Buttermilk
While you can soak most fish in buttermilk, some types tend to benefit more from the tenderizing effect and added flavor.
The best fish to soak in buttermilk include:
- Catfish – The tangy buttermilk helps offset its strong flavor.
- Tilapia – Delicate tilapia soaks up buttermilk flavor well.
- Flounder – Helps tenderize the delicate flounder.
- Rainbow trout – Buttermilk brings out trout’s flavor.
- Salmon – The fat in salmon keeps it moist, so buttermilk just adds flavor.
- Cod – Brings more flavor to the mild cod.
- Mahi mahi – Tenderizes this firm-fleshed fish.
The results with oily fish like tuna, swordfish, mackerel, and bluefish are less noticeable. The bold flavors of these fish tend to overpower the subtle buttermilk.
Buttermilk Substitutes
Don’t have buttermilk on hand? You can use these substitutes:
- Yogurt – Plain yogurt has a similar tang as buttermilk. Use an equal amount.
- Lemon juice or vinegar – Add 1 tablespoon per cup of milk and let sit for 10 minutes.
- Sour cream – Thinned out with a bit of milk to buttermilk consistency.
- Milk and cream – Mix 1 cup milk with 1/4 cup heavy cream.
- Powdered buttermilk – Whisk with water per package instructions.
While not exactly the same, these substitutes can still help tenderize and add flavor to fish.
Buttermilk Fried Fish
One of the most popular uses for buttermilk with fish is fried fish. Soaking fish in buttermilk before dredging in flour or cornmeal and frying creates an incredibly tender, juicy, and flavorful fish that is hard to beat!
Buttermilk fried fish is delicious with:
- Catfish
- Tilapia
- Cod
- Haddock
- Flounder
- Rainbow trout
- Mahi mahi
The buttermilk brine followed by a seasoned flour or cornbread coating keeps the fish extra moist while frying. Here is a quick recipe to try:
Buttermilk Fried Catfish
Ingredients:
- 4 catfish fillets (about 6 ounces each)
- 2 cups buttermilk
- 1 1/2 cups flour
- 2 tablespoons Cajun seasoning
- 2 teaspoons paprika
- 1 teaspoon salt
- 1 teaspoon black pepper
- Oil for frying (vegetable, canola, peanut, etc)
Instructions:
- Rinse the catfish fillets and pat dry with paper towels.
- Place fillets in a baking dish and pour buttermilk over to cover. Refrigerate 30-60 minutes.
- In a shallow bowl, mix together the flour, Cajun seasoning, paprika, salt, and pepper.
- Remove catfish from buttermilk and dredge thoroughly in the flour mixture, pressing down to adhere.
- In a heavy skillet or pan, heat 1/2 inch of oil over medium-high heat to 350°F.
- Fry catfish 2-3 minutes per side until golden brown and cooked through. Drain on paper towels.
- Serve hot with your favorite dipping sauces.
Baked Buttermilk Fish
In addition to fried fish, another tasty way to prepare fish marinated in buttermilk is to bake it. Baking helps keep the fish deliciously moist and tender.
You can bake just about any firm white fish variety using this method. Some favorites include:
- Tilapia
- Cod
- Haddock
- Halibut
- Mahi mahi
- Grouper
- Sea bass
Bake the fish plain, marinated in buttermilk and spices, or coated in flavored breadcrumbs or flour after soaking. Bake at 375-400°F for 10-15 minutes until easily flaked with a fork.
This easy Baked Buttermilk Tilapia recipe turns out perfect every time:
Baked Buttermilk Tilapia
Ingredients:
- 4 tilapia fillets (about 6 ounces each)
- 1 cup buttermilk
- 2 tablespoons lemon juice
- 1/2 teaspoon garlic powder
- 1/2 teaspoon onion powder
- 1/4 teaspoon salt
- 1/4 teaspoon pepper
Instructions:
- Rinse tilapia fillets and pat dry.
- In a shallow dish, mix together buttermilk, lemon juice, garlic powder, onion powder, salt, and pepper.
- Add tilapia fillets and turn to coat well. Cover and refrigerate for 30-60 minutes.
- Heat oven to 400°F. Lightly oil a baking sheet.
- Remove tilapia from buttermilk marinade, letting any excess drip off. Place on prepared baking sheet.
- Bake for 10-12 minutes until fish flakes easily with a fork. Enjoy!
Buttermilk Poached Fish
Poaching is a healthy, gentle cooking method that results in tender, moist fish. Adding buttermilk to the poaching liquid enhances flavor.
Nearly any fish works well poached in buttermilk including:
- Salmon
- Halibut
- Cod
- Sea bass
- Mahi mahi
Poach the fish over low heat just until opaque and cooked through, 5-10 minutes usually. Try this easy recipe:
Buttermilk Poached Salmon
Ingredients:
- 4 salmon fillets (6-8 oz each)
- 2 cups buttermilk
- 1 small onion, thinly sliced
- 1 bay leaf
- 1 teaspoon salt
- 1/2 teaspoon pepper
Instructions:
- Pour buttermilk into a large skillet. Add onion, bay leaf, salt and pepper.
- Bring buttermilk mixture just to a gentle simmer over medium heat. Reduce heat to low.
- Add salmon fillets in a single layer, spoon buttermilk over to cover. Poach 7-10 minutes until cooked through.
- Remove salmon and onions to a plate. Serve salmon hot with the poaching liquid poured over the top.
Conclusion
While not strictly necessary, soaking fish in buttermilk can be a useful technique to tenderize fish and add subtle tangy flavor. It works best with firm white fish and is great for fried fish or lighter preparations like baking and poaching. Try soaking your fish for 30-60 minutes before cooking to see if you enjoy the difference buttermilk makes.