Cream of tartar
Cream of tartar suppliers and sourcing guide
Cream of tartar is potassium acid tartrate, the potassium acid salt of L-(+)-tartaric acid. It is recovered as a byproduct of winemaking from the crystalline deposits (argol and lees) left in tanks and barrels, then purified and recrystallized. It is used as a leavening acid in baking powder, to stabilize whipped egg whites, and to limit sugar crystallization in candy and frosting. Brands buy it as a fine white crystalline powder.
- Also known as
- Potassium bitartrate · Potassium acid tartrate · Potassium hydrogen tartrate · E336(i)
- Facts checked
- November 2026
Forms and grades of cream of tartar
Suppliers sell different products under the same name. Specify the one you need.
Fine powder
The standard food grade, milled for even blending into dry mixes.
Granular
Coarser crystals for applications that dissolve it in water first.
Food grade (FCC)
Tested to the Food Chemicals Codex monograph referenced in 21 CFR 184.1077.
USP grade
Pharmacopeial grade for supplements and other regulated uses.
What to check on the COA
Compare each result with your own specification when the lot arrives.
- Assay (titration)
- Potassium acid tartrate content on a dry basis by titration with sodium hydroxide.
- Loss on drying
- Moisture content, which affects flow and dose.
- Lead and heavy metals
- Lead and other metals by ICP-MS against FCC limits.
- Ammonia and insolubles
- Purity tests from the FCC monograph that catch processing residues.
- Particle size
- Sieve analysis, which affects dissolution and reaction speed.
Storage, lots and expiry
Storage and shelf life
Store sealed in a cool, dry area; it is stable but can cake if it picks up moisture. Keep it away from bicarbonate until blending. Shelf life follows the supplier specification, with a retest of assay and moisture for older stock.
Lots and expiry dates
Record country of origin and grape source if the supplier provides them, since supply follows wine production. Check assay and particle size on each lot and rotate stock FEFO.
Regulatory status
Facts from regulators and standards bodies, each linked to its source.
21 CFR 184.1077 identifies potassium acid tartrate, also called potassium bitartrate or cream of tartar, as a byproduct of wine manufacture.
Source: ecfr.gov (opens in a new tab)The same section affirms it as GRAS for use in food with no limitation other than current good manufacturing practice.
Source: ecfr.gov (opens in a new tab)7 CFR 205.606 lists potassium acid tartrate among nonorganically produced agricultural products allowed in products labeled "organic" when not commercially available in organic form.
Source: ecfr.gov (opens in a new tab)Health Canada's List of Permitted pH Adjusting Agents, Acid-Reacting Materials and Water Correcting Agents includes potassium acid tartrate as an acid-reacting material in baking powder.
Source: canada.ca (opens in a new tab)
This is general information, not regulatory advice. Status differs by country and by how the ingredient is used, so check the rules for your product and market.
Cream of tartar suppliers
Manufacturers and distributors whose own websites say they sell it.
We are checking cream of tartar suppliers now
Every listing is checked against the supplier’s own website before it goes live, so this list fills in over the coming weeks. The specs and COA checklist above are ready today.
Sell cream of tartar? Request a listingFrequently asked questions
What forms of cream of tartar can brands buy?
Common forms include fine powder, granular, food grade (FCC) and uSP grade. Ask each supplier for the specification sheet of the exact grade they quote.
What should the COA for cream of tartar include?
Expect assay (titration), loss on drying, lead and heavy metals, ammonia and insolubles and particle size, each with its method, specification and result for that lot.
How should cream of tartar be stored?
Store sealed in a cool, dry area; it is stable but can cake if it picks up moisture. Keep it away from bicarbonate until blending. Shelf life follows the supplier specification, with a retest of assay and moisture for older stock.
What is the regulatory status of cream of tartar?
21 CFR 184.1077 identifies potassium acid tartrate, also called potassium bitartrate or cream of tartar, as a byproduct of wine manufacture. The same section affirms it as GRAS for use in food with no limitation other than current good manufacturing practice. 7 CFR 205.606 lists potassium acid tartrate among nonorganically produced agricultural products allowed in products labeled "organic" when not commercially available in organic form. Health Canada's List of Permitted pH Adjusting Agents, Acid-Reacting Materials and Water Correcting Agents includes potassium acid tartrate as an acid-reacting material in baking powder.
More acids, preservatives and leavening
- Citric acid2-hydroxy-1,2,3-propanetricarboxylic acid · E330
- Malic acidDL-malic acid · L-malic acid
- Lactic acid2-hydroxypropanoic acid · L(+)-lactic acid
- Tartaric acidL-(+)-tartaric acid · 2,3-dihydroxybutanedioic acid
- Fumaric acidtrans-butenedioic acid · E297
- Acetic acidethanoic acid · glacial acetic acid
- Phosphoric acidorthophosphoric acid · E338
- Glucono-delta-lactoneGDL · glucono delta-lactone
- Adipic acidhexanedioic acid · 1,4-butanedicarboxylic acid
- Sodium citratetrisodium citrate · trisodium citrate dihydrate
- Sodium lactatesodium 2-hydroxypropanoate · E325
- Sodium acetatesodium ethanoate · E262
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