What does bitartrate mean?
Bitartrate is a chemistry term for a salt or ester of tartaric acid in which only one of the acid's two acidic hydrogen atoms has been replaced by a metal or organic group. In other words, it is the halfway stage between tartaric acid itself and a fully neutralized tartrate salt. By far the best-known example is potassium bitartrate, which forms naturally as crystalline deposits during wine fermentation and is purified and sold in kitchens as cream of tartar, valued for stabilizing egg whites and preventing sugar syrups from crystallizing. Other bitartrates, such as choline and sodium bitartrate, appear in nutritional supplements and pharmaceutical formulations. The word belongs to technical registers — food science, medicine, and oenology — rather than everyday speech, where it surfaces almost always as part of a longer chemical name. Its root is the same Latin 'tartarum' that gives us tartar and tartaric acid, tying the word directly to the history of winemaking.
nounA salt or ester of tartaric acid in which only one of the acid's two carboxyl groups has been neutralized; the most familiar example is potassium bitartrate, commonly known as cream of tartar.
- A singly neutralized salt or ester of tartaric acid, containing the hydrogen tartrate anion HC₄H₄O₆⁻.
"The winemaker scraped the potassium bitartrate crystals from the bottom of the barrel."
"Potassium bitartrate precipitates as crusty crystals along the walls of wine casks during fermentation."
"The recipe calls for half a teaspoon of potassium bitartrate to stabilize the beaten egg whites."
The plural denotes multiple distinct bitartrate compounds rather than countable quantities of one substance.
"Several bitartrates, including the potassium and sodium salts, are approved as food additives."
That gritty film inside your wine bottle is potassium bitartrate — better known as cream of tartar, the same powder that stiffens your meringue.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of bitartrate
Bitartrate derives from the prefix 'bi-' combined with 'tartrate', which traces back through French to Latin 'tartarum', meaning tartar — the crusty deposit that accumulates in wine casks — ultimately borrowed from medieval Latin and likely of Arabic or Greek origin via 'tartaron'. The 'bi-' prefix here signals partial neutralization, indicating that one acidic hydrogen remains in the salt. English use of the term developed alongside modern chemistry in the eighteenth and nineteenth centuries, when systematic naming of acid salts became established, and it shares its lineage with cognate terms such as tartrate, tartar, and tartaric acid.
How bitartrate is actually used
Bitartrate is a technical term found chiefly in chemistry, pharmacology, food science, and winemaking. In everyday contexts it usually appears as part of a full compound name such as 'potassium bitartrate'; the household equivalent, cream of tartar, is far more widely recognized. The plural refers to different compounds or specimens rather than countable grains.
Easily confused with bitartrate
A tartrate is a fully neutralized salt of tartaric acid, whereas a bitartrate retains one acidic hydrogen and is only half-neutralized.
A bicarbonate is the analogous half-neutralized salt of carbonic acid, not of tartaric acid.