Classification
Product TypeIngredient
Product FormCrystalline Powder
Industry PositionFood Additive Ingredient
Market
Potassium sodium L(+)-tartrate (also known as sodium potassium tartrate or Rochelle salt) is a standardized food additive used globally for technical functions including sequestration, stabilization, and acidity/pH control. It is recognized in international additive systems (INS 337) and in major regulatory frameworks such as Codex GSFA and US FDA regulations, which supports cross-border sourcing and use when local permissions are met. Commercial supply is linked to tartaric-acid/tartrate supply chains, including recovery associated with wine manufacture, which can introduce exposure to viticulture-driven variability. Demand is primarily downstream of processed-food manufacturing needs where chelation/sequestration and pH management are required.
Specification
Physical Attributes- Occurs as colorless crystals or a white, crystalline powder
- Cooling saline taste
Compositional Metrics- Chemical identity: sodium potassium salt of L-(+)-tartaric acid
- Commonly referenced composition: C4H4KNaO6·4H2O (tetrahydrate) in US food regulation context
- CAS: 304-59-6
- INS: 337
- EU additive code: E337
Grades- Food Chemicals Codex (FCC) specifications referenced in US regulation
- JECFA specifications (FAO/WHO) referenced for food additive evaluation and specifications
ProcessingUsed as a sequestrant and stabilizer (Codex/JECFA functional class context)Used as an emulsifier/emulsifier salt and pH control agent in US FDA GRAS affirmation context (GMP-limited uses specified for certain food categories)
Supply Chain
Value Chain- Upstream tartaric acid/tartrate stream (including recovery associated with wine manufacture) -> purification/crystallization -> food-grade ingredient distribution -> use in processed-food manufacturing formulations
Demand Drivers- Technical need for sequestration/chelation and stabilization in food formulations
- Use as a pH control agent/emulsifier salt in permitted applications (e.g., US GMP uses in cheeses and jams/jellies)
Risks
Feedstock Availability HighIf a significant share of supply is sourced from tartrate streams associated with wine manufacture, then shocks to viticulture (e.g., poor grape harvests or structural shifts in wine output) can tighten availability and increase price volatility for potassium sodium L(+)-tartrate in global ingredient channels.Pre-qualify multiple suppliers with different upstream sourcing routes, monitor grape/wine sector supply indicators, and use contracts and safety stock for critical formulations.
Regulatory Compliance MediumPermissions and conditions of use for E337/INS 337 can differ by jurisdiction and by food category, so non-aligned labeling or use levels can create border rejections or reformulation risk in international trade.Maintain a jurisdiction-by-jurisdiction additive permissions matrix (Codex, EU, US and target markets) and verify use levels/label declarations before export.
Quality And Contaminants MediumFood-grade material must conform to recognized specifications (e.g., FCC/JECFA); off-spec impurities, incorrect hydration form, or misidentification with related tartrates can cause quality failures or non-compliance in regulated markets.Specify FCC/JECFA compliance in procurement, require batch COAs, and apply periodic third-party testing for identity and key impurities.
Sustainability- Feedstock exposure to viticulture and wine-sector dynamics because sodium potassium tartrate may be obtained as a byproduct of wine manufacture
- Climate variability affecting grape production can indirectly influence availability and pricing of tartaric-acid/tartrate-derived inputs
FAQ
What is potassium sodium L(+)-tartrate (E337/INS 337) used for in food?It is used for technical functions such as sequestration and stabilization (as described in the JECFA functional class context) and is also listed in US FDA inventory/regulation context as an emulsifier/emulsifier salt and pH control agent. In the United States, 21 CFR 184.1804 describes GMP use as an emulsifier and pH control agent, including use in cheeses and jams and jellies under current good manufacturing practice.
What are the key identifiers and names for this additive?Common identifiers include CAS 304-59-6, INS 337, and EU additive number E337. It is also called sodium potassium tartrate or Rochelle salt, and it is described as the sodium potassium salt of L-(+)-tartaric acid in US regulation and major chemical databases.
Is there an established acceptable daily intake (ADI) for potassium sodium L(+)-tartrate?Yes. The WHO JECFA database lists an ADI of 0–30 mg/kg body weight (expressed as L(+)-tartaric acid) for potassium sodium L(+)-tartrate, and EFSA’s re-evaluation of tartaric acid and tartrate salts references an ADI of 30 mg/kg body weight per day for L(+)-tartaric acid and its sodium and potassium salts.