What to use instead of soda water

Q: What can I use instead of soda water for carbonation and dilution in a drink?

Sparkling mineral water (1:1). Faintly salty and more mineral, with softer bubbles that die sooner. It reads rounder in a citrus drink. Tonic water (1:1, minus 1 tsp of syrup per serve). Sweet and quinine-bitter, so the drink stops being neutral. Fine in a cooler, wrong in a Ramos fizz. Ginger ale (1:1, and drop the syrup entirely). Sweet and spiced, and it goes flat faster. The drink lands about 8 g of sugar heavier per serve even with the syrup gone. Home-carbonated tap water (1:1, carbonated cold and used within a minute). The hardest bubbles of any of these if the water is properly cold. Warm water holds almost no gas, so chill it first.

Q: What can I use instead of soda water for aerating liquid in a frying batter?

Cold lager or pilsner (1:1). Carbonation plus alcohol that flashes off early, so the crust goes crisper and browns deeper. Tastes faintly malty. Sparkling water with baking powder (1 cup sparkling water + 1/4 tsp baking powder per 1 cup soda water). The powder keeps lifting after the bubbles are gone, so the crust puffs more and browns paler. Ice-cold still water with baking powder (1 cup water + 1/2 tsp baking powder per 1 cup soda water). Denser crust with a coarser bubble. It survives a batter that has to sit for a few minutes better than carbonation does.

It depends entirely on what it's doing in the dish. Here's the job, what else does it, and what to skip.

Carbonation and dilution in a drink

The bubbles carry aroma up out of the glass and the water opens the drink out, which is why a mojito tastes brighter than the same mix stirred flat.

Sparkling mineral waterRan out

1:1

Faintly salty and more mineral, with softer bubbles that die sooner. It reads rounder in a citrus drink.

Where to buy it →

Tonic waterRan out

1:1, minus 1 tsp of syrup per serve

Sweet and quinine-bitter, so the drink stops being neutral. Fine in a cooler, wrong in a Ramos fizz.

Where to buy it →

Ginger aleRan out

1:1, and drop the syrup entirely

Sweet and spiced, and it goes flat faster. The drink lands about 8 g of sugar heavier per serve even with the syrup gone.

Where to buy it →

Home-carbonated tap waterRan out

1:1, carbonated cold and used within a minute

The hardest bubbles of any of these if the water is properly cold. Warm water holds almost no gas, so chill it first.

What doesn't work: Still water with a squeeze of lemon. The acid is not the missing piece. Without carbonation the aromatics stay down in the glass and the drink tastes heavy however well you balance it.

Aerating liquid in a frying batter

Dissolved gas expands in hot oil and leaves a lacy open crust, which is what makes a tempura or beer batter crisp rather than bready.

Cold lager or pilsnerRan out

1:1

Carbonation plus alcohol that flashes off early, so the crust goes crisper and browns deeper. Tastes faintly malty.

Sparkling water with baking powderNo alcohol

1 cup sparkling water + 1/4 tsp baking powder per 1 cup soda water

The powder keeps lifting after the bubbles are gone, so the crust puffs more and browns paler.

Where to buy it →

Ice-cold still water with baking powderNo alcohol

1 cup water + 1/2 tsp baking powder per 1 cup soda water

Denser crust with a coarser bubble. It survives a batter that has to sit for a few minutes better than carbonation does.

Where to buy it →

What doesn't work: A bottle that has been open in the fridge overnight. Flat water gives a heavy doughy coating and you cannot tell by looking, so open a fresh one for batter.

Club soda carries added minerals and seltzer does not. In batter it makes no difference; in a tall drink club soda tastes fuller.