Cleanliness is one of the most important aspects for all food preparations; this is even truer for Brewing. In Brewing we provide good growing conditions for yeast which are also good conditions for other microorganisms, especially wild yeasts and bacteria. Cleaning practices must be maintained through each stage of the brewing process.
Nine Rules for Cleaning and Sanitising:
- You can only sanitise clean equipment
- Dirty equipment always contains bacteria.
- Cleaners are NOT sanitisers. Weather acid or alkaline, cleaners should NOT be used as the final procedure.
- Sanitisers are NOT cleaners. Sanitisers should be used ONLY as the final procedure
- The more heat and the longer the contact time, the better and easier a cleaning job will be.
- DO NOT over use cleaners. Never use the rule “if a little is good a lot will be better”. Generally “a lot” is bad. Higher concentration may not work well, require more water to rinse, may leave a chemical residue, or just cake and plug equipment.
- Cleaners and sanitisers can only do their job if they come into direct contact with soils and surfaces. This means that all surfaces must be directly soaked or hand cleaned with cleaners, and then directly soaked with sanitisers.
- Always add cleaning or sanitising chemicals to water. Never add water to chemicals.
- Never use just one sanitiser. Rotate the sanitiser you use often to prevent build-up of resistance to any one type.
The definition of sanitisation is to reduce bacteria and contamination to insignificant and manageable levels. The terms clean, sanitise, and sterilise are often used interchangeably but should not be. Items may be clean but not sanitized. Here are the definitions:
- Clean: To be free from dirt, stain, or foreign matter
- Sanitise: To kill/reduce spoiling microorganisms to negligible levels
- Sterilise: To eliminate all forms of life especially micro-organisms, either by chemical or physical means (harsh chemicals, heat, and pressure)
Cleaning & Sanitising
This is the process of removing all the dirt and bio-films from a surface, thereby removing all sites that can harbour bacteria. Cleaning is usually done with a correctly formulated brewing detergent (no perfumes, enzymes, or chlorine) and elbow grease. None of the sanitising agents used by home brewers are capable of eliminating all bacterial spores and viruses. The chemical agents brewers use will clean and sanitise, but not sterilise. However sterilisation is not necessary. Instead of worrying about sterilisation, home brewers can be satisfied if they consistently reduce these contaminants to negligible levels.
All sanitisers are meant to be used on clean surfaces. A sanitiser’s ability to kill microorganisms is reduced by the presence of dirt, grime and organic material.
Organic deposits can harbour bacteria and shield the surface from being reached by the sanitiser. So it is up to you to be sure that the surface to be sanitised is clean.
The Cleaners
Cleaning requires a certain amount of scrubbing, brushing and elbow grease. It is necessary because a dirty surface can never be a completely sanitised one. Deposits can harbour bacteria that can spoil beer. The ability of any sanitising agent to kill bacteria is reduced by the presence of any organic matter, so prior cleaning is necessary to complete sanitation. Below is a list of cleaners and their pros and cons.
Dishwashing Liquids
These products mostly contain perfumes that can be absorbed into our brewing equipment and released back into beer. Additionally some detergents are difficult to rinse and leave behind a film that can be tasted in beer and ruin head retention.
Bleaches
Both liquid and powdered chlorine bleaches often also contain perfumes and other additives such as enzymes and fillers. The one to use for brewing purposes is the Pink Stain Remover. As its name suggests it is used for cleaning stained equipment or if you have acquired beer bottles that need a thorough cleaning. It is very effective used in this way but is very hard on equipment (and your clothing) so its use should be limited and needs extra care when rinsing.
Sodium Metasilicate (Brewers Detergent)
Once widely available, this cleaner (not to be confused with Sodium metabisulphite which is a now superseded sanitiser) has been a very effective brewing cleaner for many years. However it is now being replaced by the easier to use, liquid, nontoxic spray on cleaners such as Morgan’s Low suds and Brewcraft’s Brewclean. Spray on cleaners greatly reduce the amount of cleaner required and are quite economical.
Automatic Dishwashers
I am often asked about using dishwashers, it is not optimal as there are a few limitations in this method.
The narrow openings of hoses, bottling valves and bottles usually prevent the water jets and detergent from effectively cleaning the inside. If it does get in there is no guarantee it will be rinsed out. And lastly the drying additives can ruin head retention in beer. These work by coating the surface in a chemical film so droplets won’t form preventing spots. The wetting action destabilises proteins that form the bubbles. It is for this reason that beer glasses should not be washed in the dishwasher.
The Sanitisers
Once your equipment is clean, it is time to sanitise it before use. All surfaces that will contact your brew need to be sanitised; such as fermenter, lid, o-ring, grommet, airlock, stirrers, thermometers and hydrometers, work surfaces, can openers and hands etc.
Percarbonates & Peroxides
Sodium percarbonate is sodium carbonate reacted with hydrogen peroxide and it is a very effective sanitiser for all types of brewing equipment. Hydrogen peroxide will effectively sanitise surfaces and containers that are already clean. As with all sanitisers, the effectiveness of hydrogen peroxide as a sanitising agent is compromised by organic soiling. Use these cleaners according to the manufacturer’s instructions, but generally use 30 ml per litre and rinse after cleaning.
One of the best properties of the per carbonate family is that they are environmentally and septic system friendly and need little or no rinsing. I am often asked about using nappy cleaning powders such as nappy san. While this product does contain sodium percarbonates (about 23%) it also contains many phosphates, enzymes and perfumes, which work well in the nappy bucket but you won’t catch me drinking from it!
Acid Sanitisers
The new kids on the block! Very effective sanitises that are also no rinse. The perfect partner for rotating with per carbonates/peroxides. A little goes a long way, a bottle will last for a long time if used according to instructions.
Sodium Metabisulphite
It is used as a food additive, mainly as a preservative and is sometimes identified as E223. It may cause allergic reactions in those who are sensitive to sulphites and should not be used by asthmatics. It was commonly used in home brewing to sanitise equipment.
When mixed with water, sodium metabisulphite releases sulphur dioxide (SO2), a pungent, unpleasant smelling gas that can also cause breathing difficulties in some people. For this reason, sodium metabisulphite has fallen from common use in recent times, with agents such as hydrogen peroxide becoming more popular for effective and odourless sanitizing of equipment.
Products available include, Morgan’s Sanitise, Brewcraft’s Brewshield and sanitise sachets.
So Remember:
Cleaning your equipment means that you have removed all of the visible dirt and residue on your equipment, but not living organisms.
Sanitising means you have treated your equipment (post cleaning) with a chemical solution that will eliminate virtually all spoilage organisms (moulds, wild yeasts, bacteria).
You MUST CLEAN your equipment BEFORE sanitising the equipment, since it is difficult to properly sanitise equipment with visible residue on it. The terminology “sterile” is the complete elimination of organisms, and is not realistic in the home brewing environment.