Chemicals
Caustic (5229 Caustic) – Caustic is the primary cleaner used by most breweries. Usually sodium hydroxide based and heavily alkaline. It is ideal for breaking down and removing organic deposits (e.g., krausen rings). You can do a bit of trading-off between time, temperature, pressure, and concentration. That said, 2-3% caustic at ~150F (66C) for 20-30 minutes through the sprayball has been a pretty good place to start for us. Caustic is dangerous because it is capable of breaking down your skin (the lye used in soap making is similar). We started with a powdered caustic (Wash-It), but given the price and efficacy we transitioned to liquid.
Phosphoric-Nitric Acid Blend (5397 Microlex Special 30) – Acid helps to remove inorganic deposits, i.e., beerstone (calcium oxalate). It also helps to neutralize any residual caustic (not that there should be any with adequate rinsing) and to passivate stainless steel. Acid blend is used at similar temperatures and cycle lengths as caustic, although slightly cooler, ~130F (54C).
Five Star Peroxyacetic Acid (PAA) – While there are many sanitizers available, PAA is the most popular for breweries. At the right concentrations it is a robust sanitizer with high effectiveness. It breaks down to acetic acid, so it can be used no-rinse. It is a powerful oxidizer, which makes it important to drain any residual before fermented beer enters a tank or keg. Our bucket was leftover from the old brewery in our space, so we bought a pack of test strips and it still reads the expected concentration after dilution.
Five Star PBW – We have a bucket of this alkaline powered cleaner for soaking hot-side equipment and other gear where we don’t want to have to be as careful as we would with caustic. We both used it at home, so were more comfortable with it than the Chlorinated Manual Cleaner we started with.
Iodophor (4330 Spark I2) – Similar to the PBW, it is nice to have a less hazardous sanitizer for spraying ports or soaking fittings. It is only effective on clean surfaces, so it is important to remove of detritus before expecting it to work.
Grain Alcohol – Given its quick kill times and evaporation ethanol is the ideal sanitizer for spray bottles and any surfaces that are highly sensitive (e.g., yeast culturing). Isopropyl alcohol is another option.
General Concepts
Pre-Heating – At this scale a tank has so much thermal mass that you can’t simply put 15 gallons (57 L) of hot water to a tank and expect it to still be hot after circulating. As a result if you want the caustic or acid to stay hot, you need to pray hot water into the tank. A tank with an electric element (like our keg washer has) helps too.
Sprayball – Most tanks have a port that leads to a sprayball, a small metal orb that spins and sprays when liquid is forced through. These aren’t always perfect, and can have blind spots, especially in ports and above it. In addition, it isn’t effective at cleaning its own exterior.