Most breweries prefer to use steam or hot water to sanitize.
Steam sterilization requires 15-20 minutes at 100 degrees Celsius. However, steam sanitization tends to create a vacuum. Therefore, chemical or physical cold sanitizing at 40 degrees Celsius is becoming increasingly popular for sanitizing large tanks.
Chemical cold disinfection includes alkaline chemical disinfectants and acidic chemical disinfectants.
The main component of alkaline chemical disinfectants is chlorine (pypocholoride). The main pypocholoride includes sodium hypochlorite, chlorine dioxide.
An active chlorine solution of 50-100 mg/kg is recommended, as this concentration has a low corrosive effect.
Sodium hypochlorite is usually available in 10-15% active chlorine solution, which is corrosive to stainless steel, aluminum and tin. According to the study, SS304 (inconel) can not be in contact with 0.3% pypocholoride for more than 4 hours, otherwise it will cause corrosion.
For 316L (inconel with Mo), it is resistant to liquids with less than 10% pypocholoride.
And common acidic chemical disinfectants include hydrogen peroxide (>30ppm H2O2
), acetic acid, peroxyacetic acid and >0.3% HNO3 solution.