Scrub Your Way to Better Beer
I’ve said many times that primarily a brewer is a cleaner, nothing more. For no matter how good your brewing skills, if you don’t clean your equipment thoroughly you will produce infected beer. And please do not think that sanitation alone is the answer, because no sanitizer will work efficiently if there are solid deposits present that are capable of harboring bacteria or wild yeasts. You have to clean off all deposits before using a sanitizer, no matter how boring a chore such cleaning may be. If you do not you will find it worse than boring to have to take a carefully designed and crafted brew and pour it down the sink because it is infected. Wort and beer contain plenty of nutrients that various bacteria (and wild yeasts) just love. Look at brewing as a constant battle against unwanted microorganisms and never forget that careful cleaning is the best defense against their depredations.
What should you clean?
Everything that has or will come into contact with wort or beer should be cleaned. Utensils such as hydrometers, stirring paddles and spoons, thermometers, the mash tun and boiler, cooling equipment, fermenting vessels, kegs, bottles, and draft dispensing lines and equipment. It may not be obvious that your mash tun should be spotless since what comes out of there is going to be boiled so that any bacteria carried over will be killed off. But, it is likely that both mash tun and boiler may be out of use for extended periods between brews. That only encourages the bacteria to use solid deposits as a refuge in which to hide and grow so that you may simply be cultivating a colony of undesirables in your brewing area. That means they will find their way into your beer sooner or later, so don’t encourage them — get both vessels scrupulously clean!
You should also think whether there are any nooks and corners where bacteria might grow, but which cannot easily be reached or inspected directly. These include things like valves, external heat exchangers, “picnic” taps, beer lines, siphon tubes and so on. If possible, take things such as valves and faucets apart and thoroughly clean them separately before re-assembly. It is also a good idea to regularly clean working surfaces and even the floors in your brewery.
If there is anything I haven’t mentioned and you’re not sure about it, clean it anyway!
How should I clean?
The first approach is to never leave anything dirty lying around, because deposits not only attract bacteria, but they harden with time and become much more difficult to remove later on. A good first step is to rinse vessels, containers, and especially bottles with hot water immediately after use. Anything left should be removed with an appropriate cleaning procedure. Exactly what that procedure might be depends upon the type of deposit; the most common culprits are yeast, protein and hop residues, and beer stone. The first three are organic, while beer stone is mainly inorganic; it is largely calcium oxalate, but will also contain some protein residues.
The four factors involved in cleaning procedures are mechanical removal of deposits, chemical removal, temperature of the procedure and the time taken at each step. Unlike commercial breweries using CIP (clean in place) systems, homebrewers do not have the same command over these factors, so our approach must be somewhat different, though not less efficient.
Mechanical cleaning is obvious and quite straightforward. It is also perhaps the most important step. In short, immediately after use rinse with hot water and scrub all surfaces in things like fermenters, bottles, and kegs. Always use soft scrubbing pads instead of wire wool for those vessels you can get your hand into easily. For those more difficult to reach spaces such as inside glass or plastic carboys, a soft bristled brush should be used – you’ll find those where the bristles are at right angles to the shaft of the brush are best. You can use the scrubber in combination with a mild household detergent for the more difficult to remove residues. The main point about scrubbing is that you do not want to scratch the surface of a stainless steel, glass, or plastic vessel as such scratches are the kind of places where microorganisms like to hide.
Chemical removal entails dissolving organic residues and beer stone with a suitable reagent. The former is generally best removed by means of an alkaline reagent, and the latter with an acidic one. Commercial brewers use quite powerful chemicals that are unsuited for use in the home, but we do have access to safer, milder reagents that are quite capable of doing the job efficiently, and I’ll discuss those later. Remember, we do not use our equipment as often as commercial brewers do, and if you clean yours right after use you will not get the kind of build-up that requires drastic treatment.
The rate of any chemical reaction increases with increasing temperature, so the hotter you carry out any cleaning procedure the better. However, the homebrewer doesn’t want to use liquid any hotter than can be safely handled, so we are generally limited to using hot water from the household supply. In fact, that is quite adequate for our purposes; especially if you have scrubbed the surfaces clean immediately after use.
Time is another variable that is important when using any cleaning chemicals. The longer the contact of a chemical with a dirty surface the better it will do its job. So the longer you can keep your equipment in contact with a hot solution of the cleaner, the more effective the results will be. However, we generally lack the ability to keep the solution hot after the beginning of the procedure, so we have to make a trade-off and soak the equipment in the requisite solution for hours, or even days. Happily, most of us do not brew every day so long soaking is practicable and a good approach for small items of equipment.
So what should you use?
There are in fact quite a number of chemical formulations for removing proteinaceous and other organic residues that are available to homebrewers. As formulations, their exact chemical make-up is proprietary but many of them contain sodium percarbonate, along with mild alkalis such as sodium carbonate and sodium silicate so that they are somewhat “stronger” than normal household detergents. Sodium percarbonate is an adduct of sodium carbonate and hydrogen peroxide and provides “active oxygen” to help break up soils, while carbonates and silicates are sufficiently alkaline to dissolve organic deposits. In addition, these formulations often contain chelating agents, such as ethylenediaminetetraaceticacid (EDTA). Chelating agents have the ability to form complexes with metal ions such as Ca2+ that are soluble in water and therefore help to dissolve beer stone when used in these formulations. In fact they act as a “claw” to grab the metal ion and thus get their name from the Greek word for claw, “chela.”
Before I mention some of these I should point out that I have no financial interest in any product or company producing them. So if what I say appears as a recommendation for any particular product it is not an endorsement and merely reflects the fact that I have used it successfully. Perhaps the most well known product is PBW (Powdered Brewery Wash) from Five Star Chemicals. It is a patented product, and was apparently developed for the Coors Brewing Company (perhaps for cleaning their copper vessels, but it also works well on stainless steel vessels). It is an alkaline formulation with its active cleaner being sodium metasilicate and it is widely used in the brewing industry. Other products in this category are B-BRITE Cleanser from BSG HandCraft, Straight A Premium Cleanser from Logic Inc., Bru-R-Ez from Birko Corp., and both Alkaline Brewery Wash and Oxygen Brewery Wash from Craft Meister. The latter also offers a keg and carboy cleaner in tablet form that obviates the need to measure out the cleaner. I have heard good comments on all of these from both craft and homebrewers.
Naturally, you should use these products according to the manufacturer’s directions, particularly their recommended solution concentrations. They are all readily soluble in water and are best used when dissolved in hot water.
Optimum contact times depend upon the extent of the deposit, but this should not be too heavy if the initial cleaning stage with a mild detergent and vigorous scrubbing has been carried out thoroughly. Normally, it may be sufficient to just spray the solution onto the surface and allow it to dry before rinsing with hot water. Scrubbing the surface should not be necessary unless the deposit is very heavy, but if it is heavy the strictures on choice of scrubber as discussed under mechanical cleaning also apply here; do not be tempted to use any kind of scrubber that may scratch the surface. If you can still see a deposit after such a procedure, then it may well be beer stone, which is best removed with an acidic cleaner such as Star San, a phosphoric acid/detergent formulation. Note that there is a good argument for throwing plastic bucket type fermenters away and getting new ones, once any level of beer stone has built up on them.
Other pieces of equipment, such as valves, picnic taps, etc. can be cleaned by soaking in a solution of one of the cleaners mentioned earlier, again using soft brushes where necessary. Immersion chillers, whether of stainless steel or copper, should always be scrubbed clean directly after use with a mild dishwashing detergent, which will prevent any buildup of beer stone or hop/protein residue. Counterflow chillers and plate heat exchangers are trickier since you can’t see the surface, and they are normally made of copper, which is a metal that reacts with both acid and alkalis. The best approach with these is simply to flush them with very hot water immediately after use; at least one supplier recommends the use of boiling water but you may find that both difficult and a little dangerous! I would suggest using a mild detergent with the hot water, then flushing very thoroughly with more hot water.
If you use kegs, perhaps in combination with a dispensing system, you need to be aware that buildup of deposits, especially beer stone can occur in the lines. That means a potential home for bacteria that can cause various off flavors in the beer, including diacetyl. So you have to clean the lines too, especially if the beer is kept on tap for any length of time. And even if you empty the keg in just a day or so, you should clean the lines immediately after removing the keg. The best approach is to simply disassemble everything and then soak the parts in a cleaning solution for several hours or more. The most commonly-used product is BLC (Beverage Line Cleaner), a formulated product from National Chemicals Inc. It is composed of potassium hydroxide, tetra potassium pyrophosphate, trisodium phosphate, and sodium metasilicate, which means that it is alkaline and must be handled with care.
If you prefer not to take the lines apart, there is a simple and inexpensive gadget you can make from a plastic pesticide sprayer (new, not used!).
Clean up
Since the chemical preparations I have described are all alkaline or acidic and they need careful handling, you might think that they should be used only occasionally. The longer you leave cleaning the more such deposits will build up and harden and become even more difficult to remove. Clean equipment frequently and regularly and just make sure that you respect the chemicals you use and wear appropriate safety equipment such as safety glasses and rubber gloves..png)
