Because bacterial damage to starch can significantly decrease performance even within the un-pasted starch granule, the following procedure should be followed at every opportunity.

• Stop agitator and drain the tank.
• Thoroughly clean the inside of the tank to remove any bacterial deposits and caked or dried starch.
• Fill the tank with clean water. Then, using appropriate personal protective equipment (PPE) add one-half gallon of commercial grade bleach to 30-60 gallons of water.
• Close the lid of the tank and restart the agitator. Circulate the bleach solution through the tank and piping for one hour.
• Drain the bleach solution from the tank. Refill the tank with fresh water and flush the system. Drain the flush water. The tank is now ready to return to service.
• This should be done whenever there is sufficient time, preferably at least once each week, especially in warm weather.
• However, even when only a short time is available, simply hosing out the inside of the tank will help remove protective deposits, beneath which bacteria can proliferate and continuously inoculate the system.

For cooked starch storage tanks there is no substitute for a good continuous biocide protection program.