8 brewing blunders that make home brew beer taste bad

So, you've taken the plunge into the world of homebrewing. You did your homework, wrestled through a few batches, and now you're ready to savour the fruits of your labour. You reach into your stash, toss a couple of bottles in the fridge, and get ready for a taste test. If that first sip is pure brewing perfection, well, hats off to you – you're a natural-born homebrewing legend!

But let's face it, the path to homebrew glory can be a bit rocky at times. And sometimes your beer just doesn’t taste right. Maybe it tastes more like vinegar, is a bit sweet, has a metallic tang or is just plain bad. We’ve all been there. 

To help you uncover why your homebrew tastes bad we've compiled a list of the eight most common hiccups that we get asked about in our homebrew stores.  We'll spill the beans on these brewing bloopers -  what causes them, and how to banish them from your beer-brewing future.

1. Infection

Ah, the sour surprise! Infection happens when your brewing gear isn't squeaky clean. This can turn your beer into a vinegar-flavoured concoction or something that rotting fruit or worse, baby vomit. 

Infection occurs when your equipment is not cleaned and sanitised properly. Dirty gear = dirty beer 🤮

The solution? Follow the cardinal rule of brewing and make sure you clean and sanitise everything – and we mean everything – with proper brewing cleaning agents like sodium percarbonate orAtomic 15 ABC. 

And then give everything a good rinse and sanitise with a no-rinse sanitiser like Atomic 15 Foaming Sanitiser..

It’s a two step process - you can’t sanitise something that isn’t clean 

2. Oxidation

Oxidation can give your beer a cardboard-like taste - not what you are after. Another tell-tale sign that your beer is oxidised is the colour will be significantly darker then when you bottled it.

Oxygen in your wort (unfermented beer) is a good thing!  It helps the yeast ramp their numbers before getting stuck into their job, to make you delicious beer!  

However, after fermentation, oxygen is a no-go. 

To avoid oxidation in your beer:

• Avoid splashing your brew when moving your fermenter after fermentation
•  Use bottling wands when bottling to minimise splashing.  Try not to shake the bottles.
• Use transfer hoses when racking, don’t just tip your beer from one fermenter to another.  Syphons can help here too
• Like bottling, use a transfer hose if kegging to minimise splashing

3. Under-attenuation

That’s a big word. Basically it means that the yeast hasn’t fully fermented all the sugars in the wort. 

Sometimes, your yeast gets tired before the party's over and it leaves your beer with an unwanted sweetness.  Maybe the yeast wasn’t the right choice for your brew or it could also have been old (and lost its spunk)

Getting the right attenuations is all about matching your yeast's abilities to your brew. Different yeast strains have different alcohol tolerances. So get to know the different yeast types and use the right one for the beer that you are brewing and the batch size. 

Also, remember to keep your yeast fresh by storing it in the fridge – just in case your yeast decides to take a nap when you need it most. And keep a few spares in the fridge, just in case.

4. Over-carbonation

Too much priming sugar, and your beer becomes a fizzy disaster (or worst case scenario, exploding bottles)

It’s pretty easy to avoid:

• Check that your beer is done fermenting with a hydrometer (most beers will finish somewhere between 1.007-1.012 SG)
• Use the right amount of priming sugar, for ease, use carbonation drops.  If you are using priming sugar - a 3-way scoop is handy to measure the right amount, make sure you mix it before bottling.

5. Acetaldehyde

This green apple-flavoured intruder happens when yeast is rushed or the fermentation temperature is too low. 

Basically, the yeast hasn’t quite finished doing its job. 

After the yeast has consumed all of the available sugars in the wort, it goes searching for other, less desirable foods, including Acetaldehyde, before going into hibernation. Make sure you give your yeast time to ‘clean up after itself’.  Once you reach your final gravity, give the yeast another day or two   at a slightly elevated temperature (no higher than 22°C should be required).

6. Diacetyl

Diacetyl gives your beer a buttery, butterscotch-like taste or aroma. It can also produce a ‘slickness’ on the tongue.

Like Acetaldehyde it's a sign that your yeast needs some extra time to tidy up. 

Try a Diacetyl Rest, especially for lagers. Raise the temperature (usually to 20-24℃) towards the end of fermentation, hold it there for 2 - 3 days, and let the magic happen.

7. Phenolics

Phenols can make your beer taste like medicine or a band-aid, and they usually sneak in through wild yeast or chlorine in your water. 

Ensure your water is chlorine-free or filtered and keep everything squeaky clean to keep those pesky phenols at bay.

8. Fusel Alcohols

These little troublemakers create a harsh, solvent-like flavour and can lead to epic hangovers. Fusel alcohols can be produced during fermentation when the yeast is under stress or when the temperature of fermentation is too high.

Keep your yeast happy with proper nutrients, oxygen, and temperature control during fermentation.

So, there you have it, your crash course in common homebrew hiccups and avoiding funky flavours in your beers. 

Remember, brewing is as much art as science, and even the legends started somewhere. We are all learning, if you’ve got questions  ask, we are here to help. Or join our brew club and come to one of our bring a brew along events to get feedback from other brewers on the flavours of your beers. 

Cheers to your brewing adventures!