These onion rings are extra light and crispy because we carbonate the batter. If you don’t have a home carbonation system, you can substitute seltzer water and a tablespoon of freeze-dried coffee. Simple home carbonation systems run the gamut from about $60 for an iSi carbonator to several hundred dollars for a carbonation rig and CO2 tank. Once you start playing with one, you’ll wonder how you ever got along without it. The tiny bit of xanthan gum in the recipe helps the batter stick to the onion slices and keeps it from separating. You can season the onion rings with salt and serve with ketchup, but we think you’ll find that the Beef Seasoning and smoked ketchup really take the flavor to the next level.

　　

Ingredients

serves 4 as a side dish

　　225 grams brewed coffee

　　0.2 gram xanthan gum (see Sources, page 309)

　　150 grams all-purpose flour

　　1 large egg yolk

　　2 grams fine sea salt

　　1.5 grams baking soda

　　Canola oil or rice bran oil, for frying

　　85 grams all-purpose flour

　　10 grams onion powder

　　3 medium sweet onions, cut into 3/4-inch (1.9-centimeter) rings

　　Beef Seasoning (page 18)

　　Smoked ketchup (see page 62)

　　

Step 1

Pour the coffee into a blender. Turn on low and increase the speed until a vortex forms in the center. Sprinkle in the xanthan gum and increase the speed to evenly disperse it. Reduce the speed to medium and add the flour, egg yolk, salt, and baking soda. Puree to just combine. Pour the mixture into a whipped cream canister and charge with one CO2 charge. Alternatively, if you have a carbonation rig, carbonate the batter to 50 psi.

　　

Step 2

Fill a medium pot half full of canola or rice bran oil and heat over medium-high heat until it reaches 350°F (175°C).

　　

Step 3

Put the flour and onion powder on a plate and mix well. Dispense the coffee batter from the whipped cream canister into a bowl. Dredge the onion rings in the onion flour mixture, dip them into the batter, and immediately drop them in the hot oil. Fry 3 or 4 rings at a time, flipping them once halfway through cooking. When they are golden brown, remove the rings from the pot with a slotted spoon or skimmer and put on a wire rack set over a baking sheet to drain. Season lightly with the beef seasoning and serve with a side of smoked ketchup.

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