Tartaric acid is a diprotic organic acid naturally found in grapes, valued by formulators for its sharp, clean acidity — often described as the most aggressive sourness of the common food acids. This guide covers what it is, where it fits in sour candy, winemaking and effervescent systems, how it differs from cream of tartar, and how to source it in bulk in Canada.
What Is Tartaric Acid?
Tartaric acid (CAS 87-69-4, E334) is a food grade acidulant supplied as a white crystalline powder. It is freely soluble in water and delivers a fast, intense sour impact with a relatively short finish compared to malic acid. It is the principal acid of grapes, which is why it is the reference acid in winemaking. As a diprotic acid, it also reacts efficiently with sodium bicarbonate, making it a classic leavening and effervescence acid.
Why Formulators Use Tartaric Acid
Sharp sour impact: the strongest perceived sourness per gram among citric, malic and tartaric — a small inclusion sharpens a sour blend noticeably.
Winemaking acid: the natural acid of grapes, used for must and wine acidity adjustment where a grape-native profile is expected.
Effervescence and leavening: reacts with sodium bicarbonate in baking powder systems and effervescent drink powders.
pH adjustment: lowers pH in beverages and confectionery syrups with a clean flavour contribution.
Stabilizing roles: used as an emulsifying stabilizer in some food systems.
Typical Applications
In sour candy, tartaric acid appears in sanding sugars and coatings where an immediate, aggressive sour hit is the goal; it is often blended with citric and malic acids to shape the sourness curve. In winemaking and cider, it is the standard acid for adjusting must acidity. In effervescent powders, its reaction with sodium bicarbonate generates carbon dioxide on contact with water. It also serves in baking powder systems, jams and jellies, and beverage powders needing a crisp acid note.
Tartaric Acid vs Cream of Tartar
The two are related but not interchangeable. Tartaric acid is the free acid — fully acidic, freely soluble, and used where strong acidity or effervescence is required. Cream of tartar (potassium bitartrate) is its partially neutralized potassium salt: much milder, less soluble, and used mainly to stabilize whipped egg whites and control sugar crystallization. Substituting one for the other changes both acidity and reaction rate, so recipes calling for cream of tartar should not simply receive tartaric acid gram for gram.
Citric vs Malic vs Tartaric at a Glance
Citric acid gives a bright, familiar sourness that fades quickly. Malic acid builds more slowly and lingers, giving green-apple persistence. Tartaric acid hits hardest and fastest of the three, with a sharp mineral edge. Most sour coatings blend two or three of them to control the timing and intensity of the sour experience — see our sour candy coating acid guide for blend ratios and coating technique.
Formulation Notes
Tartaric acid is freely soluble in water and dissolves readily in syrups and beverage bases. Because its sourness is more intense per gram than citric acid, start at lower inclusion rates when replacing citric in a formula and adjust by taste panel. In dry effervescent or sanding blends, keep the powder dry during storage: premature contact with moisture triggers the acid–bicarbonate reaction or clumping. It is heat-stable under normal cooking and candy-making conditions.
Specifications at a Glance
CAS number: 87-69-4
E number: E334
Grade: food grade
Appearance: white crystalline powder
Solubility: freely soluble in water
Documentation: specification sheet and lot-specific Certificate of Analysis available on request
Buying Bulk Tartaric Acid in Canada
LiquidShop supplies bulk food grade tartaric acid in 1 kg, 5 kg, 10 kg and 25 kg formats, with the per-kilogram price dropping sharply at larger sizes. Orders ship from Quebec with Canadian lead times — no customs or brokerage surprises — and a Certificate of Analysis for the current lot is provided on request within one business day.
