Why does my AG beer taste so bad??

A few more thoughts;

My recent Craft Beer & Brewing magazine had a section off flavours and one is a solvent type taste. the main cause is fermenting too hot (at 21c you are at the top end of WLP005) or leaching from plastics (you do say you have a cheap cool box mash tun and I wonder if this could be part of the problem).

I would be inclined to go with a dried yeast such as S04 next time, and maybe give leaf hops a try rather than pellets.


Edit.. Having re-read your original post I notice the first AG was OK. Assuming you are using the same equipment then this may point to the ingredients, especially as you have used the same for the 3 bad brews.
I would therefore be inclined to source a fresh set of ingredients from a different supplier (although I have used The Home Brew Shop for years without any problems) for your next brew. The use of leaf hops will stop any sludge carry over.

Dads_Ale said:

A few more thoughts;

My recent Craft Beer & Brewing magazine had a section off flavours and one is a solvent type taste. the main cause is fermenting too hot (at 21c you are at the top end of WLP005) or leaching from plastics (you do say you have a cheap cool box mash tun and I wonder if this could be part of the problem).

I would be inclined to go with a dried yeast such as S04 next time, and maybe give leaf hops a try rather than pellets.


Edit.. Having re-read your original post I notice the first AG was OK. Assuming you are using the same equipment then this may point to the ingredients, especially as you have used the same for the 3 bad brews.
I would therefore be inclined to source a fresh set of ingredients from a different supplier (although I have used The Home Brew Shop for years without any problems) for your next brew. The use of leaf hops will stop any sludge carry over.

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Thanks for the tip about the fermentation temp. I don't have the recipe to hand but I think the temperature was the one recommended in the recipe.

I was beginning to suspect the ingredients too although I felt like I was 'blaming the tools'! I have ordered leaf hops this time so that, as you say, the hop sludge won't get carried into the fermenter/bottles.

I have had some very high fermentation temps mostly accidentally and never had anything near a chemical taste. Could you possible be mashing at the wrong temp? Have you taken a hydrometer reading before you boil? I would check my thermometer is accurate and try some stove top brews so you can isolate whats causing it. If your grains smell good am sure that's not the problem either though
If your still considering it could be your steriliser clean the equipment as normal and top up with water and taste it. If its not rank you can rule that out as well.

Could you try tasting your wort before you ferment it to see if the taste is present before fermentation?

Even though the water may be a red herring, I found out all I needed from the water company's website, and gave very detailed analysis of hardness and other contaminants. Easier than calling them up. - To find your area (Scottish water), and Hardness data.

I made a pale ale last August soon after I started using a 25 litre boiler and I had EXACTLY the same result as is described in this thread.

I have blamed all kinds of things and I still don't know how it happened.


Posssibilities are :

- I used VWP at the time, and although I thought I was rinsing thoroughly, I can't guarantee I did it perfectly.
- Producing tannins by sparging in too hot water. (I am now careful to make sure it is never above 75C)
- I had no cooler back then and the wort took about 20 hours to cool down. This could have brought out undesirable flavours from hops and certainly affected the hop utilisation.
- I have avoided the hops I used in that brew ever since. They were Admiral (@60 and Aurora @ 0.

The taste is a sort of nasty TCP flavour. It has moderated a bit over the six months I've kept it, but it is still undrinkable. I need to chuck it and thoroughly clean the plastic barrel it has been in.

I have to say on the steriliser, I use Starsan HB, it truly is wonderful stuff. You can make a batch up and reuse it almost endlessly, as long as the PH remains at 1 or 2 (I test it with litmus paper every time) so although it seems expensive, it sits in a spare FV and gets used for a good few brews before I replace it.

It's a no rinse steriliser, so there's no risk of introducing bacteria during rinsing (Hot tap water is especially bad for this) and will never leave odd tastes, I heard you can actually drink the stuff (Don't!)

One other thing, how are you cooling the beer? As far as I understand it, the primary reason for chilling the beer quickly is that sitting at warm temps (During cooldown) increases the chance of bacteria growth, and if cooling is not done quickly it should not be left open to the elements.

Basically the main reason you want a fast start to fermentation is because the quicker you start making alcohol, the less chance there is for bacteria to survive.

You never kill all bacteria, it's in the air, and you can't work in a vacuum! But you can kill most of it and ensure that the small microbes left can't multiply enough to become a problem before the environment becomes too inhospitable for them.

Or at least, that's my understanding (Preparing to be shot down!)

If you don't have a wort chiller there's a guy on ebay sells them for about £35, and they're really nicely made.

Is there anything metallic in the mash tun etc that is corroding? What is the valve made of?

Clutching at straws here!

I agree, Starsan does sound like more of a 'worry-free' option. I use a coiled copper pipe chiller that I made myself to cool the wort after the boil.

Materials in the mash tun:
Ball valve, barb and nipple: stainless steel
Manifold: copper

I made the manifold from 15mm copper pipe and copper push fittings. I do dismantle and rinse through the manifold after using it although it can leave some copper coloured residue at the bottom of the mash tun (which I clean away) if left in there whilst still wet.

I would put the VWP as your prime suspect for this type of flavour in beer, back in my kit brewing days I had a few bottles that developed this sort of problem and I was using VWP to sanitise the bottles. At the time I wasnt aware it could affect taste and was not as fastidious about rinsing as I should have been. Starsan nowadays = No worries!

For anyone who's interested - I tasted a bottle of my latest AG (it's only been bottled for just over two weeks but I just couldn't wait!) and it tastes awesome :thumb:. Not a trace of the chemical taste. So it must have been down to me not washing the VWP out properly when sterlising. Thanks to everyone who helped me troubleshoot this :

Glad you've sorted the problem out as AG beer is awesome.
I had a couple of pints of beer down the pub last night, a beer I've always thought was pretty good (Felinfoel double dragon) and it tasted like p**s compared to my own stuff.

Yep great job, a minor blip but hey ho now you have awesome beer.. forever :)

I come to this late, but my money would have been on VWP also. Bad rinsing of VWP being the cause of one of only 2 failures I have ever suffered over many years.

I add to the calls to change cleaner and sanitiser. For me, Oxi Clean & Starsan. I love starsan as i) it's near instant sanitising and rinse free, and ii) you can consider it pretty much free given the extremely tiny amount you need to make up some solution. These things should be a side issue of no concern; let's concentrate on making great beer.

Aaaaargh! my beer has gone bad again. It only took a few more days after tasting the the first (which was great) to being overpowered by a harsh bitter taste and almost chemically smell. I'm fairly certain I've found the source of all my woes now and I'm embarrassed to say I've broken the cardinal rule of not keeping my equipment clean... the syphon tube was infected and smelly .

I've been so convinced that the problem was due to the mash/boil stages that I overlooked the obvious and took for granted that there was nothing amiss with the rest of the brewing process. On close inspection of the syphon tube I could see stuff growing in it that was probably not washed properly after the first AG (the honey ale) that I attempted. I do wash the tube clean before and after use and leave it in the sanitiser for 10 - 20 minutes. I guess this stuff was firmly stuck on inside though and I didn't think to look closely enough. It smelled like cheesy feet :sick:. So the tube has been promptly chucked and replaced with a new one so I can bottle my next brew at the weekend.

And yes I do feel like the number one idiot in all of homebrew land!

At least it looks like you have found the cause :)

I always used to use VWP but found over time a brown residue started to form in the boiler. When I had a Grainfather on trial I bought some PBW and decided to try and clean the boiler. What a difference, all of the brown scum came off and it looked as good as new.
I now clean everything with PBW and sanitise on brew day with StarSan.

Dads_Ale said:

At least it looks like you have found the cause :)

I always used to use VWP but found over time a brown residue started to form in the boiler. When I had a Grainfather on trial I bought some PBW and decided to try and clean the boiler. What a difference, all of the brown scum came off and it looked as good as new.
I now clean everything with PBW and sanitise on brew day with StarSan.

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Thanks for the tip. I plan to get some StarSan for my next brew so will grab some PBW too.

Well rather embarrassing as earlier in the thread i claimed to not had anything near a chemical taste. I will now be ditching 3 brews as soon as i get time as they have an unpleasant solvent taste. Rather gutted as one of them would of been lovely. http://howtobrew.com/book/section-4/is-my-beer-ruined/common-off-flavors

BeerCat said:

Well rather embarrassing as earlier in the thread i claimed to not had anything near a chemical taste. I will now be ditching 3 brews as soon as i get time as they have an unpleasant solvent taste. Rather gutted as one of them would of been lovely. http://howtobrew.com/book/section-4/is-my-beer-ruined/common-off-flavors

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Have you identified the possible cause?

BeerCat said:

Well rather embarrassing as earlier in the thread i claimed to not had anything near a chemical taste. I will now be ditching 3 brews as soon as i get time as they have an unpleasant solvent taste. Rather gutted as one of them would of been lovely. http://howtobrew.com/book/section-4/is-my-beer-ruined/common-off-flavors

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Sorry to hear that mate.. 3 brews absolutey gut wrenching!!

what do you suspect? high temps? possibly sanitiser?

I've also recently discovered that I have a slight infection issue going on.

I've discovered a recess inside the sample tap of my fermenters that didn't get cleaned in my normal routine and yeast residue buildup has been left behind. I can only assume producing a minor bacterial infection leaving a yeast twang to my last few brews.

Needless to say the sample tap now gets stripped down at the clean stage after every ferment. So it's not only good sanitising but also meticulous cleaning that needs attention.


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