Stainless steel is used in almost every stage of the beer brewing process. It is a material ideally suited to food and drink production, as it is easy to clean, does not taint food products, and can be sterilized. It is also extremely robust, and is used in products that boil liquids for long periods of time. It is also perfect for use in the chilling processes. The lorries that we see on our roads transporting milk and beer carry these liquids in stainless steel tanks, which are hosed out after each journey by specialist truck cleaning operators.
Brewers make extensive use of stainless steel, but sometimes, smaller breweries will clad their equipment in copper, for a traditional look, this will not extend to the fittings used. They will always now be stainless steel to prevent conamination. Old-fashioned brewing techniques are no longer possible, due to health concerns. Before the arrival of stainless steel, beer was fermented in wooden barrels, which needed a great deal of maintenance. Not only did they have to be laboriously cleaned out but, even when clean, there were often bugs and organisms still present which could easily taint batches of beer. The inside of the wooden containers would need to be re-pitched to keep them waterproof, and there is no doubt that pitch would taint the beer during the storage process.
Hygienic hose fittings and other technical advancements, mean that contamination of beer via dirty equipment is a thing of the past. Stainless steel has offered revolutionary improvements to the food and drink industries: from the super-effective stainless steel hydraulic hose fittings used in lifting gear, to easily sterilized tanks and joints, every aspect of transport and production has benefitted the food production business.
The Brewing Process Brewing can be broken down in to about nine processes, almost all of which involve stainless steel equipment. After milling and malting the grain goes through the following procedures before beer is finally produced.
• Mashing – this is a process whereby malted milled grain is mixed with water, and heated, to allow the production of maltose. Enzymes are triggered to break down the starches in the grain, and convert them into sugars. This is process takes place in vast stainless steel tanks.
• Lautering is a process that aims to separate extracts produced during the mashing stage, which is known as wort. This is done in a stainless steel ‘lauter tun’, or a mash filter.
• The wort is then boiled to sterilise it, and hops can be added in various quantities. Each beer has a different recipe. The boiling takes place in stainless steel boiling tanks, and must be an even boil which last between one and two hours.
• The cooled wort is then allowed to ferment, a process that begins with the addition of yeast. Once the yeast is added and fermentation has begun, the liquid can finally be called beer.
Fermentation tanks can be huge, depending on the size of the brewery. Some large breweries have cylindroconical tanks that look like silage silos, and which are conical at the base and cylindrical at the top. The yeast and other debris created during fermentation will collect in the cone at the bottom of the tank, and can be drained out via a port. During fermentation, the sugars from the malt begin to metabolise into alcohol and carbon dioxide. Whilst this occurs, the yeast and other solids will gradually sink down to the base of the tank. Heating and Cooling
The heating processes in small breweries are sometimes done via direct fire techniques – literally heating kettles of wort over a fire. Smaller breweries will maintain this quaint tradition, but commercial breweries use pressurised steam. The cooling process is facilitated by the use of cooling jackets, which are applied to the storage tanks, with the temperature controlled by the cooling operator. The operators have full control of the temperature of each tank, allowing for adjustments to be made to each recipe. If large batches of one type of beer are being made, the whole area containing the tanks will be cooled.
Next time you raise a glass in your local pub, think of the stainless steel used at every stage of its production, all of which has contributed to its taste and safety.