Why Stainless Steel?
Stainless steel couplings are a very popular choice for home brewers and commercial breweries alike, because of the unique properties of the material. Stainless steel is an alloy made from iron, nickel, and chromium, and while it does have its drawbacks (it isn’t weldable, for example), the benefits are significant. Stainless steel is highly durable – it is very resistant to corrosion, and tough enough to withstand a good deal of physical punishment. It has a low thermal conductivity, which makes it ideal for low-heat applications. The only exception to its resistance to corrosion is in the event it has been improperly cleaned or maintained.
Stainless steel couplings tend to be slightly more expensive than their brass or aluminum counterparts, but the increase in reliability makes them worth the cost. Stainless steel also has the advantage of not contributing any additional flavors to or reacting with the brewing process – stainless steel is essentially inert in contact with beer. As compared to a material such as brass, stainless steel will not react with the brewing process, making it good for longer-term storage.
Maintaining and Cleaning Stainless Steel
While stainless steel couplings are resistant to corrosion and physically durable, they do need to be properly maintained and cleaned. The most common cause for corrosion in stainless steel couplings is improper maintenance or cleaning – do not use steel wool or metal brushes to clean stainless steel, as this can cause pitting and oxidation, which leads to corrosion. The best way to clean stainless steel is by using a common household cleaner such as Bar Keeper’s Friend or Kleen King, as these are designed for use with a softer scrub. These cleaners help achieve a passive surface, because the acidic content strips the metal to allow a fresh oxide layer to form (they also work very well with copper).
Another common cause of corrosion in stainless steel brewing equipment is beerstone deposits building up over time. Beerstone is a combination of protein and mineral deposits that become set against the surface of the steel, which eventually leads to the metal losing contact with oxygen (and thus its oxide layer). This can also cause the surface to become pitted, allowing corrosion to form. In order to prevent this issue, the surface should be cleansed using a caustic cleaner followed by an acidic cleaner, as this will help break up the deposits.
Lastly, do not store stainless steel plate chillers full of sanitizer or water – this can lead to galvanic corrosion through biological agents. Always rinse and drain your plate chillers before storing them. you can read the full info here.
