adventures in craft beer in Perth and beyond

Beer Interpretation #5: Oxidation // Part One

Beer Interpretation is an irregular series of posts where I try to decipher the sometimes strange and always wonderful world of beer jargon, phrases and catch cries by drilling into the basics and interpreting the lingo. In short I’m going to try and translate the nerdy beer stuff …


In every glass of beer there’s an incredible amount of passion, hard work and science that has come together to create it. The journey that takes a bag of grains and other ingredients and turns them into beer is simple yet complicated. Getting the finished the beer to you, the happy person drinking it, is equally simple yet complicated. It’s such a long trip from the making of a beer to the drinking of a beer and occasionally something can go wrong, the result is a beer that doesn’t taste the way the brewer intended – a beer with a fault and one example of a fault is oxidation.

To tackle the complicated topic of oxidation I needed to bring in a couple of big guns from the local brewing scene and so I got in touch with Paul Wyman and Steve Blaine.

Paul Wyman at GABS Melbourne earlier this year

Paul is the head brewer at Colonial Brewing Co, Margaret River and Steve is the Craft Beer Ambassador for Lion Nathan in WA, he also recently became a Certified Cicerone. Over a couple of beers at Petition Beer Corner we chatted about oxidation, ate some chips and had a few laughs too.

You can follow both Paul @6foot6brewer and Steve @the_wa_beer_runner on Instagram

Steve Blaine at GABS Sydney earlier this year // Photo Credit: The Beer Pilgrim

Let’s kick this off and dive into part one of a two part post …

“oxidation”

What is it exactly?

Draft Magazine defines oxidation as “an off flavour that transpires when beer is exposed to oxygen or high temperatures, or is otherwise past its prime.”

Basically it’s beer that is stale and old or one that’s been hit with heat or oxygen snuck in where it wasn’t supposed to.

“Heat is the enemy. All chemistry speeds up as the temperature rises.”

Tasting Beer by Randy Mosher

How does it happen?

A great read on oxidation can be found at Professor Beer, an American website written by George de Piro who is the brewmaster at Druthers Brewing Company and a Master Judge in the Beer Judge Certification Program.

“Oxidative reactions are always occurring in beer, regardless of how it is stored,”

Professor Beer

Yep, that’s right, you heard the man, so it’s not surprising to then realise that time itself will bring about oxidation.

Time …

“Every beer will oxidise eventually,” Paul says. “Even beers that are supposed to be aged like barley wines and imperial stouts eventually will get that papery, cardboard character given enough time,” continues Steve.

We seem to forget that beer is a consumable, it’s not supposed to last forever. Sure, there’s pasteurisation that extends beer shelf life – a post for another day I suspect – but this doesn’t magically turn beer into some kind of heat resistant super liquid.

One of the best ways I’ve seen the importance of time communicated is in Stone Brewing (US) Enjoy By series of IPAs. Each release features the date in huge print on the front and it’s the date that the brewers want you to drink the beer by and it’s about five weeks from the date the beer is bottled.

Screenshot (22)

Heat …

“Temperature is an absolute critical component to oxidation, the hotter the beer the quicker it happens,” says Steve. “Yeah, you’re just speeding up the reaction,” confirms Paul.

Steve uses a basic rule of thumb taught to him by Russ Gosling, head brewer at Little Creatures in Fremantle, “A beer will be ‘brewery fresh’ for three days if it’s stored at 30 degrees, thirty days if it’s stored at 20 degrees and 300 days if stored at ten degrees.”

This is why you hear some beer lovers talk adoringly about their favourite brewery that cold stores and cold transports their beers. Keeping beer cold is all about keeping oxidation at bay.

Feral Brewing puts its well, “treat like milk” they say and it’s a great way to think about your beer though probably not something to add to your breakfast routine. A significant difference between milk and beer, in the context of freshness, is that whilst bad milk will make you feel ill, bad beer won’t. “It is this durability that leads people to believe that beer can withstand all sorts of abuse,” Professor Beer writes.

What does oxidised beer taste like?

Sometimes you’ll hear someone describe a beer as being “tired”, “old” or “stale” and that’s oxidation at work. Remember, time is not a friend to many beer styles. There’s a reason that many craft breweries talk about drinking beer fresh.

Obviously “tired” is a bit of an obscure descriptor, well how about “flabby”? That’s one way that Steve describes tired and oxidised beer. “It just falls to the side of your palate,” Steve describes, “and that for me is the biggest indicator of oxidation. You drink it and it just becomes astringent, like you just sucked on a teabag.”

Often oxidised beers are described as tasting papery, like wet-cardboard, or even having a sherry or cheesiness to them. You might notice that these descriptors are pretty varied and that’s because it depends on how badly or in what way the beer is oxidised. It’s also improtant to remember that we don’t all taste beer the same way.

We are all beautiful and unique snowflakes …

Everyone perceives flavours differently, tasting beer is completely subjective. What one person tastes as corn might taste like tomato to someone else, what is green apples to you is pumpkin to the person beside you. The trick is to figure out what oxidised beer tastes like to you, not to anyone else and this takes some time, a little education and, of course, some beer drinking.

Understanding oxidation isn’t easy …

“I’ve only really understood oxidation well in the last six to nine months,”

Steve Blaine, Certified Cicerone & Craft Beer Ambassador

Steve had the benefit of the expertise at Little Creatures Brewing (part of his employer’s, Lion Nathan, portfolio) whose brewers who took him through what he describes as an “intensive session” on how to detect oxidised beers. It involved comparing a nine month old bottle of Little Creatures Pale Ale, their flagship American style pale ale, that had been kept at warm even hot temperatures to a fresh pale ale.

If you want to get your science on, this is absolutely something you can do at home if you don’t mind deliberately harming your beer. Pick something local, something fresh – have a look at the dates on the bottle or can – and leave it in the sun for a few hours and/or up to a day and then put it back in the fridge. Be sure to mark it so you know it’s the beer you have messed with. Give it a few more weeks and then taste it against the same fresh beer and see what the differences are.

To step the science up a notch you can look online for a beer sensory kit that provides you with liquid capsules containing the flavour fault which you then put into a beer.

Once you start to get the idea of what oxidised beer is and tastes like it’s generally agreed that it won’t leave you, you’ll get better and better at knowing when it’s there. “As soon as your brain is switched on to it you can’t switch it off which is a great thing,” says Steve.


Part two of this post will be up soon, continuing with oxidation and looking at where it can happen and how we as drinkers can avoid it.

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