Potassium Aluminum Sulfate (Potash Alum)

Potash alum, KAl(SO4)2, supplied predominantly as the dodecahydrate. The classical alum of historical food and traditional medicine use, primarily applied as a firming agent in pickling and as a clarifier in selected beverage applications.

Colorless to white crystalline powder or transparent crystals. Astringent taste, soluble in water with acidic pH due to aluminum cation hydrolysis.

We supply food-grade Potassium Aluminum Sulfate from manufacturers in China holding ISO, Halal, Kosher and other certifications relevant to the product and production. Aluminum-additive use restrictions in several jurisdictions should be confirmed against the destination market before purchase.

Common market grades include food-grade dodecahydrate (pickling alum), pharmaceutical USP/EP grade, cosmetic-grade alum block material for personal-care applications, and industrial grade for water treatment, leather, and dyeing.

Bulk and reduced-MOQ shipments. Batch-level COA covering assay, aluminum content, iron, heavy metals, and microbiology.

Potassium Aluminum Sulfate has been known and used since antiquity, with documented use by Egyptian, Greek, and Roman civilizations for pickling, dyeing, and medicinal preparation. The crystalline material was traded across the Mediterranean world and into Asia long before its chemical composition was elucidated in the nineteenth century.

Modern production proceeds by reaction of aluminum hydroxide with sulfuric acid and potassium sulfate, followed by crystallization of the dodecahydrate. The product crystallizes in characteristic octahedral crystals that historically gave the substance its commercial identity. Industrial grades are produced from bauxite-derived aluminum sources; food and pharmaceutical grades are further refined.

Regulated in the EU as E522, with the same aluminum-additive restrictions applicable in several jurisdictions as for SAS (E521). JECFA established a Provisional Tolerable Weekly Intake for aluminum from food additives. Customers should confirm current regulatory status for the destination market before specifying potash alum in finished products. In the United States, the substance is permitted as a Generally Recognized as Safe firming agent under 21 CFR 182.1131.

Mechanism in pickling is calcium-pectate-like cross-linking, with aluminum ions binding to demethylated pectin in vegetable cell walls to generate firm crisp texture. The same astringent action explains its long history as a mouth-rinse and antiperspirant ingredient. As a clarifier in syrups and selected wines, alum coagulates suspended protein and colloidal matter into filterable flocs.

Strategic positioning: Potash alum is the traditional, recognizable form of alum for home and artisan food applications, where pickling crisp and historical authenticity are the value drivers. Industrial-scale leavening has shifted to SALP and SAPP; traditional pickling and confectionery applications still source alum dodecahydrate.

• Pickling crisp-up agent in traditional cucumber, watermelon-rind, and cherry preserve recipes
• Firming agent in candied fruits and crystallized confections
• Clarification in selected wine, vinegar, and sugar-syrup processing
• Astringent in dental, oral-care, and traditional medicine applications
• Mordant in natural-dyeing and textile applications outside the food sector
• Antiperspirant and personal-care active ingredient in alum-block and crystal-deodorant formats
• Flocculant in water treatment
• Fire-retardant and tanning applications in non-food industry