Soda water

Savory & ferment· ferment vinegar

What it is

Soda water is water carbonated by dissolving pressurized gas into it, plain or lightly mineralized.

What it tastes like

On the nose: acid; the house adds clean, sparkling, neutral ✳.

Salt and acid

Salt

0 mgAsian pear10 mgCinnamon100 mgFennel seed1,000 mgOlive10,000 mgFish sauce

Sodium 21 mg per 100 g — USDA FoodData Central 174842.

Acid

Acid not measured yet.

Every one of its 2 compounds carries a paper the library can cite.

carbon dioxidetastereads as faint acid taste (PubChem)Measured in 1 of 338 ingredients.cite
prepared and rated at 0.0, 1.5, 2.0 and 2.8 volumes of CO2 per volume of water at approximately 5 °C, with the paper noting that 2.8 V/V is slightly lower than levels in typical carbonated soft drinks; a second experiment used 0.0, 1.0 and 1.6 V/V. The study's finding is that the bite does not come from the bubbles: pungency ratings at normal atmospheric pressure and at 2.0 atmospheres, where bubbles cannot form, were essentially identical. — Wise et al. 2013, PLoS ONE (Methods, Stimulus materials, on the carbonated water samples prepared for the main study; and Procedures, on the carbonation levels used in the bubble-timing experiment)
carbonic acidtasteacidMeasured in 1 of 338 ingredients.cite
named by the paper as the proximal stimulus for the pungent aspect of carbonation: acidification of tissue and embedded trigeminal nerve endings due to enzymatic hydration of CO2 to carbonic acid by carbonic anhydrase. The paper states this from the literature it cites rather than measuring it, and separately notes, also from the literature, that stimulation of taste cells by carbonic acid could give carbonated water a subtle taste. — Wise et al. 2013, PLoS ONE (Abstract and Introduction, on the physiological basis of carbonation sensation, with the paper's citations to the studies that established it)

Sources