• Add the oil to a large, heavy bottomed pot or deep fryer and heat the oil to 365 degrees F. I highly recommend using a frying thermometer or instant read thermometer for the easiest and best frying experience.
• 1290 grams neutral oil
• In the meantime, pat the fish dry with a paper towel and season with salt and pepper on both sides. Slice the fillets into 3-inch by 1 inch strips and set to the side.
• 2 pounds firm white fish fillet,salt & pepper to taste
• To prepare the batter, add the flour, baking powder and seasoning to a large bowl and whisk until combined. To the flour mixture add the milk, water and sourdough discard and whisk until smooth.
• 70 grams all-purpose flour,2 grams baking powder,6 grams salt,2 gram garlic powder,2 gram onion powder,2 gram black pepper,120 grams milk,60 grams water,120 grams sourdough discard
• Once the oil is preheated, dip a strip of the fish in the batter until it is completely covered and quickly place it into the hot oil. Repeat with 2-3 more strips of fish. You don’t want to overcrowd the pot with fish, otherwise the oil temperature will drop and the fish won’t fry properly. This will make the fish taste soggy, rather than crispy.
• Fry the fish for about 3-4 minutes, or until the batter is perfectly golden brown all around. If the fish is especially thick, you might need to fry for an additional minute. Fully cooked fish should reach the internal temperature of 145 degrees F.
• Remove the sourdough fried fish with a wire spoon and place them on top of a wire rack. Avoid placing the fish directly on a paper towel, I found this caused the batter to lose its crispiness.
• Make sure the oil reaches 365 degrees F again before repeating another small batch of fish. Continue to repeat this process until all of the fish has been fried.
• Serve warm and enjoy!

Ingredients & Substitutions

• Fish – The best fish for frying is white, mild, lean, and has a sturdy texture that stands up well to hot oil. I used cod, but other great choices include haddock, tilapia, and flounder.
• Flour – I used all-purpose flour for this recipe.
• Sourdough Discard – I prefer to use sourdough discard that’s no older than 1-2 days. The older the discard, the more tangy the flavor will be. You can use active sourdough starter, just make sure to use the same amount in grams.
• Baking Powder – Just a touch of baking powder helps this batter fry up super light, crispy and airy. Double check that your baking powder isn’t expired. Swap it out every 6 months.
• Seasonings – Some home bakers prefer a simple fish batter with just salt and pepper, but I love a touch of extra seasoning from garlic and onion powder. For a bit of heat, try adding a dash of cayenne powder, or add some paprika for a smoky flavor.
• Frying Oil – You’ll want to use a neutral-tasting frying oil with a high smoke point, like avocado oil, beef tallow, or vegetable oil. Stay away from olive oil because it doesn’t handle high heat well and isn’t a great match for deep frying.

Tips

• It’s important to keep the oil temperature consistent. Remove from the heat or low the heat if it is getting too hot. The oil will drop once you add the fish, so it is important to not overcrowd the pot. Allow the temperature to return to 365 degrees F before each batch of fish. To save yourself a headache, invest in a frying thermometer or instant read thermometer.