1.5 lbs Trisodium Phosphate (TSP).
Some homebrewers use this along with Oxiclean Versatile Free or another percarbonate based cleaner as a homebrew cleanser. The ratio I’ve read is 30% TSP and 70% Oxiclean, but I’ve never tried this myself.
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Reminder: Always read and follow manufacturer’s instructions. If you have a question about the suitability of any product for a particular application, contact the manufacturer.
Also Consider: Five Star PBW Cleaner (Powdered Brewery Wash), 4-Pound Jar