25 July 2022
Revealed: 4 Bad Beer Taints, How to Spot Them, and What to Do When You Find Them
Knowing how beer should taste and, almost more importantly, how it shouldn’t taste is one simple way of preventing a problem before it becomes a complaint.
Without this skill set in your team, there’s a risk that quality control will end up being the responsibility of your beer-loving customer, which could double your problem.
👋🏻 Help is at hand.
At Avani Solutions, we know as much about nasty, off flavours in beer (also called ‘taints’) as we do about delicious, perfectly served pints.
Knowing how beer should taste and, almost more importantly, how it shouldn’t taste is one simple way of preventing a problem before it becomes a complaint.
Below is our beginner’s guide to spotting when beer’s gone bad, why, and what to do about it.
Tainted love: Four of the worst taints and how to spot them…
1. Trichloroanisole or TCA (Pronounced: tri-chloro-anisole) – a chemical released by fungi
Tell-tale signs of Trichloroanisole/TCA?
Commonly found in beer lines that have been out of use for a while, trichloroanisole causes a ‘water taint’.
Even very little TCA in the lines can taint beer. Its taste and smell are reminiscent of old, musty buildings, such as churches, where damp and mould are a problem.
What causes Trichloroanisole/TCA?
The main cause of TCA seems to be when dirty lines are left in chlorinated water.
So, the first way to avoid it is to NEVER leave your lines in water!
Soggy pythons caused by leaks and broken insulation are also thought to contribute to water taints, as this is where the TCA can leach into lines.
NEVER leave your lines in water!
How to fix this taint
If you find this taint you have two options, either replace the lines or commission an Avani SOS Level 3 taint removal procedure.
2. Dichlorophenol or TCP (Pronounced: Di-chloro-phenol) – essentially a mixture of chemicals made from coal tar
Tell-tale signs of Dichlorophenol/TCP
The TCP taint tastes and smells just like the bottles of liquid antiseptic you’ll remember from childhood.
It’s that strong-smelling antiseptic odour and flavour associated with hospitals.
What causes Dichlorophenol or TCP?
It can come from reactions between chlorine compounds in cleaning chemicals and phenols – which are naturally present in beer.
Heavy use of chlorine-based chemicals can be another culprit, but as tap water is chlorinated this can be a cause too – especially if combined with non-food grade hoses.
Very rarely, it can be a fault with the line itself – but if that’s the case you’ll spot the problem from the first day after installation of new lines.
How to fix this taint
Avoid this taint by always following usage instructions for chlorine-based products and ensuring your cellar is equipped with food-grade hoses.
If only certain products in your range are affected (particularly darker beers, where subtly phenolic flavours are intentional) then consider using a chlorine-free beer line cleaner, like Desana MAX fp as a maintenance cleaner.
always following usage instructions for chlorine-based products and ensuring your cellar is equipped with food-grade hoses.
You may need an AvaniSOS L3 treatment to get rid of the taint.
Also, take note of the information on trichloro anisole above, as dichlorophenol/TCP is also thought to be a precursor to this taint.
3. Infection – contamination and/or spoilage
Tell-tale signs of infection
No need for tricky scientific terminology for this taint. We’re talking about contamination that makes beer taste of vinegar or rotten vegetables.
What causes infection?
Dirty beer lines are the most common culprit, in which a variety of bacteria mix with beer to form acetic acid and other contaminations.
Infection can also happen during the brewing process if wild yeasts manage to get into the brewhouse.
But breweries are so alert to the risk that some even have hospital-grade air filters to prevent it!
How to fix this taint
Avoid the problem with top-notch hygiene practices from cellar to glass.
Ensure you have a regular and thorough line cleaning regime, carried out to the highest standards by thoroughly trained staff or entrust the role to professional service providers.
By the way, leaving chemicals in your lines for longer won’t help. Always follow the manufacturer’s instructions!
Ensure you have a regular and thorough line cleaning regime, carried out to the highest standards
4. Oxidisation, AKA ‘oxidation’ or known by the scientific term trans-2 nonenal – staling caused by exposure to oxygen
Tell-tale signs of oxidisation
Humans can’t live without it, but oxygen is one of beer’s biggest enemies. Put simply, when air gets to beer, it starts to go stale.
If a beer tastes like cardboard or reminds you of licking an envelope, then it’s oxidised. If it’s heavily oxidised, it can start to taste leathery or even like sherry!
when air gets to beer, it starts to go stale.
What causes oxidisation?
With draught beer, the main cause is from kegs that have been broached and left on sale for too long.
The sometimes-intermittent nature of the trade makes this far more of a common fault. It can also happen at the keg-filling stage, but this is far rarer.
How to fix this taint?
Avoid the problem by aiming to always sell a keg within 5 days.
Ensure line connectors fit properly and keg changing procedures are carried out quickly and efficiently.
If you receive complaints about papery, ‘cardboardy’ beer, take the offending keg off sale and review how quickly that beer is selling compared to your other draught products.
Ensure line connectors fit properly and keg changing procedures are carried out quickly and efficiently.
You may find you can’t justify the number of beers you have on sale in these challenging times and perhaps need to consider temporarily reducing your range.
We believe that knowledge is power. We hope our guide empowers you to understand the causes of bad-tasting beer, helps you raise the bar on beer quality and serve the tastiest beer possible!
Avani Beer Quality Technicians are experts at solving problems with taints. Get in touch to learn more about Avani SOS and how we can help your team raise the bar on beer quality.
