In this brewery chemical cleaning quick guide, I wanted to get away from my usual long form articles. Instead putting together, a quick guide to the chemicals most used in brewery cleaning.
As I literally just wrote something shorter out, to answer the enquiry below. Which, I received from a brewer, via Facebook Messenger.
The enquiry reads:
“G’day Neil. Could I ask what cleaning chemicals
that you use in the Brewery?
We are thinking:
- High concentrated Caustic
- High concentrated Acid
- Isopropyl Alcohol
Wanting to know how to predict volumes and concentrations etc. Thanks in advance!”
As someone who has been brewing for over 25-years around-the-world. I know there are certain chemical cleaners, used by the majority of breweries. Three main ones in fact.
Now, some of you reading this, may use different chemicals. Or perhaps, similar cleaner/sanitizers, but with different names.
In this post, I’ll list the chemicals used in 85% of breweries I’ve worked in. Plus, how they are used, with the first being caustic.
Caustic Soda Chemical Cleaner – Brewery Chemical Cleaning Quick Guide
The chemical used in the majority of breweries, to clean vessels from mash tun to brite beer tank.
Caustic soda (sodium hydroxide), is used by commercial brewers because it’s a very effective cleaner of soiled brewing equipment.
In breweries where the water is hard, caustic can form sold precipitates, which reduces its effectiveness.
So, to counteract this many caustic cleaners made for use in the brewing industry, contain sequestrants. Also known as chelants; these chemicals bind with the calcium. Which, causes water hardness, and prevents it from acting with the caustic.
As well as containing sequestrants, look for caustic cleaners containing “low-foam surfactants” too. This will ensure efficient cleaning and residue-free rinsing.
Homebrewers note: PBW (Powdered Brewery Wash), is a homebrewing alternative to using a caustic cleaner. It relies on sodium metasilicate, a chemical which cleans like caustic, but is less aggressive.
PBW is also mixed with a sequestrant called EDTA, as well as various surfactants to ensure effective cleaning. I used to use it when I brewing on a 700-liter system in Bermuda, and it worked well.
Reaction with CO2
Please note: Caustic soda will react with carbon dioxide, forming a solid precipitate. Sodium hydroxide in solution, combines with CO2 gas, to from solid sodium carbonate.
You need to ensure a tank has been purged of carbon dioxide, before using caustic. If not, then the reaction can reduce the effectiveness of the cleaning, as well as implode a tank too!
The easiest way to avoid this is, to let the pressure off the tank first. Preferably letting the CO2, vent to the outside. As you don’t want to fill you cellar with CO2, and asphyxiate yourself.
Then give the tank a rinse with cold water first, and then hot water after. To pre-heat the vessel before adding the hot caustic solution.
With normal chemical suppliers, concentrations are usually between 1 and 4% depending on how badly soiled the vessel is.
The temperature should be between 50°C to 70°C (between 120°F to 160°F). For good wetting power and a thorough cleaning.
Brewery Chemical Cleaning Quick Guide – Acid Cleaners
Every brewery needs to stock an acid cleaner too. This cleaner is usually a nitric/phosphoric mix. Acid cleaners are often used in a two-step regime, along with a caustic cleaner.
Whilst the caustic works on heavy soil, tannins, resins, glucans and hop oils. An acid detergent, works on beerstone, water scale (calcium and magnesium carbonates), as well as aluminum oxide.
Furthermore, acids detergents are more effective against bacteria, than caustic-based solutions.
Phosphoric Acid Detergents
Phosphoric acid is good at removing beer stone, although to be effective the cleaning solution needs to be at least 16°C (60°F).
As well as beerstone; phosphoric helps in the removal of deposits like protein material resins and yeasts. These acid detergents work better with the addition of an acid stable surfactant. Which promotes penetration of surface deposits.
Plus, aids in the effectiveness of rinsing, at the end of the cleaning process.
Nitric Acid Detergents
Nitric acid will also remove beerstone and other inorganic compounds. This, also has biocidal properties.
However, in brewing those biocidal properties are more stable and less hazardous, when mixed with phosphoric acid.
“Biocidal products are defined as active substances and preparations that contain one or more active substances, put up in the form in which they are supplied to the user, intended to destroy, deter, render harmless, prevent the action of, or otherwise exert a controlling effect on any harmful organism by chemical or biological means.”Quote from sciencedirect.com to explain biocidal properties.
So yeah, most breweries stock a nitric/phosphoric detergent like Proton from Chemron. Which is why I recommended it to the brewer, who made the initial enquiry.
The image below, shows the instruction for using Proton from Chemron; their nitric/phosphoric cleaner. Instructions would be comparable for similar detergents, made by other manufacturers.
Peracetic Acid (PAA for Short) – Brewery Chemical Cleaning Quick Guide
PAA is the third chemical, used in most commercial breweries. It’s popular, as it has broad antimicrobial activity, and also “compatible” with beer.
PAA is made by mixing acetic acid and hydrogen peroxide in an aqueous solution. Which is often assisted, with a sulfuric acid catalyst.
When in concentrated form, it smells like acetic acid or vinegar. It’s an ideal antimicrobial agent, due to its high oxidation potential. PAA is effective against bacteriophages and spores with a broad killing spectrum.
Peracetic Acid is an effective cold sanitizer, across a wide range of temperatures from 0 to 40°C (32 to 104°F), as well as a range of pH (1 to 7.5).
Furthermore, it’s also non-foaming, making it an excellent choice for cleaning applications.
PAA is Unstable
Peracetic acid is relatively unstable, breaking down readily into acetic acid (acetate), water, and atomic oxygen. It’s worth noting however, this form of oxygen carries less risk of oxidization, if properly drained before filling with wort/beer.
You must ensure, the PAA has been drained properly, before filling the brewing vessel. For example, I had a brewing acquaintance tell me…
In my large brewery roles in particular, we’ve had to destroy large quantities of beer and cider, where the tank and or the long inlet / outlet leg or spray-ball supply line has not been adequately drained.
The result was the PAA has dramatically oxidized the product – not cheap at 1200 hl of high gravity beer waiting to be diluted at the filler!A note of caution from a brewing acquaintance
PAA shouldn’t represent an oxidization problem, as long as the liquid has been well drained. However, in many large breweries, they still rinse with sterile water after using PAA, as standard practice.
In smaller and older breweries this often isn’t possible. As the resources aren’t available and there’s a possible risk of re-introducing yeast and bacteria with the rinse water.
PAA is actually certified for use in the brewing of organic beers, as the breakdown products are all environmentally friendly.
However, like all other chemicals we’ve discussed today, PAA must be handled with the utmost care, and the correct PPE (personal protective equipment) must be worn.
Other Chemicals Including Citric Acid – Brewery Chemical Cleaning Quick Guide
When running a brewery, brewing vessels need regular passivation. Passivation is the treating of stainless steel with an invisible/protective layer or coating. So, the metal is protected from corrosion and pitting.
Which can be caused when using the other cleaning chemicals we mentioned above; acids, caustics and sanitizers. As well as with carbon dioxide and beer itself.
In the past, most breweries used high concentrations of a nitric/phosphoric detergent (up to 25%) to passivate tanks when passivating tanks. A better/safer option is to use citric acid.
It’s easy to source in its raw powder form…
- Actually, if you want to accentuate “citrus” notes in a beer, you could use citric acid, when lowering mash pH…however, I digress.
Passivation can be accomplished with citric acid concentrations of between 4 and 10%, in warm water, for roughly 30-minutes. For more information, please see this document.
Brewery Chemical Cleaning Quick Guide – Alcohol in Spray Bottles
Last but not least, we’ll look at using alcohol in spray bottles. Ideally, using ethanol alcohol is preferred.
Research has shown using 70% ethanol, with the remaining liquid being water, will be more effective.
Although certain companies use “proprietary ingredients”. The alcohol at 70%, is actually more effective than if it’s at 90 or 95%.
The water helps the ethanol penetrate the bacterial cells better. In biology labs, 70% ethanol is most widely used to wipe down lab benches. The use of alcohol on a clean surface will kill bacteria in a matter of seconds.
I always keep, a few spray bottles of 70% alcohol, in my brewery cellar. When connecting a fitting or hose to a tank, the fittings are given a good spray with alcohol first.
Same, when taking tanks samples too. I’ll give the sample tap a spray before and after use, some brewers like too light the alcohol as an extra step as well.
Brewery Chemical Cleaning Quick Guide – Conclusions
Thanks for reading our “brewery chemical cleaning quick guide”. It turned out to a little longer than I was expecting.
However, I think it’s provided enough information for most newer brewers to choose the right chemicals for their brewery cleaning regime.
If you’ve any follow-up questions or feedback please, feel free to reach out. My email address is:
Likewise, if you’ve any other brewing projects you’d like to discuss, from sourcing good quality brewing equipment within a budget, to improving beer processing get in touch.
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Thanks for reading, happy brewing and have a great day.