by Michael Shade, IQS Editor
For my birthday a few years ago, I received a Mr. Beer® home brewing kit from my parents, complete with ingredients, instructions and all of the vessels needed to facilitate the transformation of wort (which is sugared, flavored brown goo, basically) into moderately comestible, ideally non-poisonous beer. The kit comes complete with a little plastic barrel fashioned after a wooden brewing barrel, a set of ingredients and sanitizing solutions, and it all comes packed in a box with a picture of a fellow holding a big glass of beer and wearing a very satisfied expression on his face. It would be generous to say that since receiving my beer kit, I brew beer at an amateur level. Heck, it’d be generous to call it “brewing” at all. The process involves heating and stirring the wort supplied in the kit for 45 minutes and then pouring the mixture into the plastic barrel. And let me tell you – that plastic barrel is no food grade tank.
The most labor-intensive part of the whole process is sanitizing the plastic tank. A brew kit is a lot like a chemistry set; to get the results you want, you have to carefully control your handling of all of your equipment and chemicals. If, for example, you fail to thoroughly sanitize your brewing barrel, rogue bacteria and other contaminants can influence the chemical reaction in the brewing process in ways that could make the beer unpalatable or even sickening. The good folks at Mr. Beer® probably chose plastic for their brewing barrels because it’s cheap – cheaper to buy and cheaper to form into barrels. But plastic is hardly an ideal material for building a brewing tank.
Plastic is susceptible to scratching, and those scratches can become like bunkers for unwanted microorganisms. That’s why, if you go to an actual brewery, or to any food or beverage processing facility, you don’t see big, plastic tanks. You see metal, food grade storage tanks. A storage tank can be described as “food grade” if it meets certain criteria, most of which pertain to the tank’s ability to store food without imparting unwanted chemical properties unto its contents while they’re being stored or processed. 304 stainless steel is often the material of choice in the construction of food grade tanks because it’s strong (which means it can be used to store or process large amounts of material without becoming deformed or rupturing) and easy to sanitize. It’s also non-reactive and corrosion-resistant, which means that a 304 stainless steel tank won’t contaminate its contents with rust.
Stainless steel tank image courtesy of G & F Manufacturing Company.
Stainless steel isn’t the only material used in the construction of food grade tanks. In fact, plastic is sometimes used for the storage of food or beverages that are intended for eventual consumption by humans. Water, for example, is chemically inert. For that reason, it is often stored in plastic tanks, particularly in developing countries. Plastic is an inexpensive alternative to stainless steel, and in the case of water storage it performs just as well. Plastic tanks can be used for the storage of non-liquid comestibles as well.
It’s no secret that we all need food, and in order for our agricultural infrastructure to meet that need, we need a processing and storage infrastructure of sufficient size and quality to satisfy the logistics of feeding people – processing, storage and transportation. If you eat food, there’s a good chance that you benefit from the food industry’s use of plastic tanks. If your diet is dairy-intensive, or if, like me, you drink a lot of beer, then you really rely on food grade tanks. When I think about what a pain it was sanitizing my plastic beer barrel, I realized that a world without food grade tanks is not a world I want to live in.