# Crap loads of acetylaldehyde in red ale with WLP004



## Mozz (29/5/16)

I'm making a red Ale using WLP004. First go with a liquid yeast.
Made a big healthy starter and according to calcs should have pitched around 0.75 million cells per oPlato. 
You can see pic below. No chill wort 60L and the starters.

Starters made on DME & yeast nutrient.





I gave the wort a good shake and mix with the Barmix to aerate and pitched the decanted yeast at 18C. 
Wort has good Ca levels and yeast nutrient.

After 24 hours it was raging and I had to fit a blow off. 


At 4 days it's at 1020 and I had a taste. Holy crapola. The acetylaldehyde blows your head off.
Is this normal and will the yeast be able to clean up so much? I can't remember tasting so much before.
I know I can just wait and see but I'm too impatient.


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## manticle (29/5/16)

Firstly time is your friend. Acetaldehyde is a natural part of fermentation and in a normal, healthy ferment, should be turned to ethanol.
Secondly, if it persists, another healthy active starter/krausening can help reduce/remove.

Thirdly - how sure are you it's acetaldehyde? Green apple, pumpkin skin and synthetic paint emulsion are how I experience it. Pumpkin and paint are quite specific but green apple can easily be confused with red apple caused by an ester (ethyl hexoanate). In my experience, a couple of yeasts are prone to high production in early stages but its presence diminishes/integrates with some conditioning and yeast settling time.

So yeah - patience. My cake hasn't cooked.
Well leave it in the oven longer.


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## Mozz (29/5/16)

Just assuming it's acetylaldehyde. Got a second opinion (had to force my wife to taste it for me). Not a fan of green beer for some reason.
Definitely apple (possibly red) and even some nashi pear but no pumpkin or paint. It's just so strong you can't taste anything else over it.


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## manticle (29/5/16)

Any anise/aniseed?


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## manticle (29/5/16)

1020 and acetaldehyde is no surprise by the way.


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## Mozz (29/5/16)

No anise/aniseed.

Just querying the amount.
I've been using US05 and this WLP004 is just behaving completely different. 
Hopefully my yeast is healthy enough to clean it all up. Seems a big job.


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## drsmurto (29/5/16)

A dose of potassium metabisulfite will remove acetaldehyde if the yeast doesn't clean it up.


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## Mozz (29/5/16)

Sounds interesting Dr Smurto. I know I'm a long way from needing to do something like this. Just interested in the chemistry.


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## Mozz (19/6/16)

So beer kegged and gassed. It is truly bizarre. 
No head what so ever and tastes more like sasaparilla than beer. No gross off infected flavours and crashed beer and yeast cake looked good to me.

Where did it go wrong?


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## TheWiggman (19/6/16)

Possibly still an infection. I've never had spider webs and huge bubbles before but I've definitely had 'infections', as the beers developed very unusual flavours that worsened over time. You may have something foreign in there as well.


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## GalBrew (19/6/16)

If it tastes like sarsaparilla I would go with infection.


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## Mozz (19/6/16)

Grrrr.. Actually you could get used to the taste. Only 60 L to go.


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## chaositic (19/6/16)

What smurto suggested can be achieved with a campden tablet. You don't have to break into your neighbours meth lab to use their equipment or anything its pretty easy.

Oh and don't try to use a garlic crusher to crush the tablet. It busted the arse out of mine and made the missus rather cranky.


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## GalBrew (19/6/16)

You can get potassium metabisulfite from most homebrew shops. It's not a big deal.


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## Adr_0 (19/6/16)

100% agree with the above - in terms of aging the beer - but I'll throw high temperature in there too. Sure it didn't get a few degrees too warm for a stretch? I've even had it in beers that had no trace, then it came up in bottle conditioning due to high temperature storage (28-35C). So the amount that is produced goes up with temperature - that is, more than what is always produced anyway.


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## Mozz (19/6/16)

I'll give it a go. Will have to wait a few weeks while I'm away. It will be interesting to see what difference it makes. I'm sure Reinheitsgebot was barley malt, hops, water and campden tablets or something like that.


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## Mozz (19/6/16)

Just reading your post Adr_0. Pitched at 18 and had the temp probe fixed to the side of the fermenter. At 1020 I bumped the temp up to 24 C but it already had heaps of what I put down to acetaldehyde?? I'll leave it another few weeks and taste again then give the campden a shot on one of the kegs to see the difference.
Just disappointing because I hit the numbers spot on through the mash etc, took great care with the water chem and through stepping up the yeast. However something didn't go right.


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## /// (19/6/16)

Red apple (ethyl hex) is and indicator of a raced ferment, but stopping at 20 is an unhealthy ferment low in oxygen. Google and you will find enough references to the causes


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## Mozz (19/6/16)

It didn't stop at 1020. That's just when I bumped up the temp (aka Brulosophy method). It finished at 1014 as expected.
The ferment definitely raced along- it went nuts.
Could it be that even with the probe on the side of the fermenter the internal temp of the brew got too high?
(Even taped on with insulation it mostly reads the fridge air temp)
A red apple taste is probably more accurate than green. 
If so what to do next time. Go lower than 18C to slow it up a bit?
Also what's the opinion on gassing with oxygen. Will that limit ethyl hex type production?
Cheers


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## TheWiggman (19/6/16)

Check the SG now, see if it's still 1.014. If it's dropped a bit then you can pretty much confirm a foreign nasty has ruined your day. I think if you fermented at 18°C there should be no need to drop the temp further. If it was >25 then yeah, but 18 works for everyone else and taping the probe on the side makes minimal difference. 
Has a fellow brewer had a sample?


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## Mozz (20/6/16)

The Gravity has not dropped.
The aroma reminds me of my old mans wine cellar. True wog wine maker. Relied completely on the wild yeasts on the grapes for the ferment. He made some rough ones and a couple of decent ones over the years.


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## MHB (20/6/16)

Personally I suspect its an infection - lots of bugs out there that like living in beer.
Other main causes are related to yeast, mainly yeast health, pitch rate and wort aeration.
One thing you could try is adding some more fresh wort, even a bit of D/LME in water to kick the ferment off again. Yeast can metabolise Aldehydes very effectively while it reproducing and will often reduce the total Aldehyde content very effectively.
Mark


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## TheWiggman (20/6/16)

Mark raises a good point about the yeast (as he does), I've noticed you've got 2 x demijohns which I assume are 5l filled to about 4l. How did you go about starting them? Single vial into each at 1.040? Or two vials? Or did you step them up incrementally? The stepping up process is often the source of confusion/fault and easy enough to do wrongly.


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## Mozz (20/6/16)

Yeast was 1 vial into 2L and grown using Shaking method. Cold crashed then stepped up to 2 x 3L and similarly grown out in 1040 LME. Should have given me a good pitch rate. 
Was pretty careful with transfers etc (used to work as a microbiologist so my aseptic technique should be OK) but certainly doesn't mean I didn't get an infection at some point.

Mark I've already cold crashed and kegged. So not sure if what your saying is still an option?

Anyway the concensus seems to be an infection rather than a process problem. 

I'll leave it age another 3 weeks and look back in on it.


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## kaiserben (21/6/16)

On Saturday I pitched a 1.2L active starter of WLP004 into 1.048 wort at 18C. I had to move it out of the fridge 12 hours later and put it in an insulated cupboard, where the air temp was 22C on Sunday night. Air temp now steady at 21C. 

So a fairly similar scenario to the OP. 

My gravity has gone down to 1.013 (so far). It tastes good and I don't detect any acetylaldehyde. Maybe the slightest whiff of juicy fruit/bubblegum, but I don't get that when tasting, just some nice fruity esters. Plenty of yeast in suspension in the sample. It should still drop another couple of points and will clear up quite a bit before I package it up. 

Sounds like OP just got unlucky with an infection.


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## Mozz (6/7/16)

Well may have my answer. Travelling through Scotland as I write and making it my mission to try as many cask ales as possible. In the village of Applecross I had a red ale from the Isle of Skye Brewery and no shit it tastes pretty much exactly like my brew, with what I call a sasaparilla like flavour. 
Not the flavour I was expecting but maybe that's just what it is. My wife likes it so I let her know there's at least another 50 L to get through at home.
The Skye Red won "Champion bitter of Scotland in 2013"


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