First time brewer with a temperature question!

[ForzaAlbion]

Hi, my name's Neil and I put my first brew on yesterday; a Coopers Aussie Pale Ale. It looks to be fermenting fine, but my kit says not to let it get below 21 degrees. I got home from work today and the thermometer read 18-20 degrees. How will this affect the beer and fermentation?

Any help greatly appreciated!

 

[graysalchemy]

18 - 20 is fine Above 21 you will get off flavours and 23+ you will get fusal alcohols which will taste solventy and give you a hangover.

 

[ForzaAlbion]

Cheers, thanks very much! :)

 

[anthonyUK]

The Aussie pale ale kit uses a mixture of Coopers Ale + Lager yeast so is very tolerant of both low and high temps.
You should have no probs at all in that temp range and I don't agree at all with GA's opinion with regards to the kit yeast but would agree if you were using recovered yeast from their own pale ale which is probably more of a lager strain.

Coopers kit yeasts - http://www.coopers.com.au/the-brewers-g ... sts&t=1803

 

[ForzaAlbion]

Chose a good one for my first brew then! It looks like it's fermenting really well, got lots of froth on the stop and starting to get a brown ring round the top. Seems to have stabilised around 18-20. Cheers for the replies guys, I'm sure I'll have a few more questions as the week goes on - can't wait to bottle it!

 

[Pearlfisher]

the kits I've made up three batches of recommend fermenting at around 28 degrees C .

 

[graysalchemy]

Go ahead and brew at high temps but you will be making fusal alcohols and off flavours to boot. But hey I won't be drinking it. :thunb:

 

[anthonyUK]

Are you speaking from personal experience GA?

 

[graysalchemy]

Oh Yes. It is a simple scientific fact that high temperatures encourage the production of fusel alcohols - heavier alcohols that can have harsh solvent-like flavors. Many of these fusels esterify during secondary fermentation, but in large amounts these esters can dominate the beer's flavor. Excessively banana-tasting beers are one example of high esters due to high temperature fermentation.

Why do you think we go to the extreme of fermentation fridges to control temps.

 

[graysalchemy]

I don't agree at all with GA's opinion with regards to the kit yeast but would agree if you were using recovered yeast from their own pale ale which is probably more of a lager strain.

Since when did you use a lager yeast in a pale ale? Most larger kits in actual fact actually use an ale yeast because they are easier to ferment with out having to cool. This however doesn't mean excessive temps.

 

[anthonyUK]

Sorry but there are a lot of ifs and cans. Have you experienced this issue or not and provide details.


Coopers use a mix of lager and ale yeast in their pale ale kit hence the reason I mentioned it.
This in turn leads to a very forgiving yeast temp range which from a manufactures point of view is easily understandable given the kit is Australian.

 

[oldstout]

Sorry but there are a lot of ifs and cans. Have you experienced this issue or not and provide details.

It is lager BTW

Coopers use a mix of lager and ale yeast in their pale ale kit hence the reason I mentioned it.
This in turn leads to a very forgiving yeast temp range which from a manufactures point of view is easily understandable given the kit is Australian.

GA is right

I totally ruined 40 pints of Coopers European lager over Christmas brewing too hot at around 24'c or above

Disgusting result which I still kegged and then had to chuck down the drain after three weeks. :sick: :sick: :sick:

The great thing about this forum is there are people who really know their stuff - listen (read) and learn

:

 

[anthonyUK]

Oldstout - the Coopers Euro lager uses a lager yeast so 24' would've been too high

A little bit of knowledge is a dangerous thing.

The great thing about this forum is there are people who really know their stuff - listen (read) and learn

I agree but sorting the wheat from the chaff is necessary as with any public forum.

 

[Pearlfisher]

Go ahead and brew at high temps but you will be making fusal alcohols and off flavours to boot. But hey I won't be drinking it. :thunb:

From the instructions -

"The fermenting temperature needs to be higher than with a normal kit and this can be achieved with a simple heat mat .Pitching the yeast at 30C and placing the fermenter straight on a heat mat will ensure a temperature of 28C is maintained .This attention to temperature control will produce a lower finishing gravity and give a cleaner taste."

They're his best selling kits and also the most expensive I've come across.

 

[graysalchemy]

Anthonyuk and all of you who believe you can brew at *bove 24c safely perhaps should read Chris White and Jamil Zainasheff's excellent book 'Yeast- The practical guide to beer fermentation'. One startling thing it points out is that beer fermented at 18c will have an acetaldehyde leval of 7.98 ppm, this rises to 152.19 ppm at 24c . Now since it is detectable on the palate at 10ppm I know what temp I want to brew my beer at.

This site does have a great deal of knowledge and experience all of which freely given to anyone willing to ask. I think someone who doesn't know what the optimum temp for fermenting a lager yeast or what type of yeast is used in a pale ale should be taken with a pinch of salt, because he clearly doesn't know what he is talking about.

And yeast a little bit of knowledge is dangerous but no knowledge is worse.

 

[anthonyUK]

GA - I haven't said it was safe to brew at those temps. In general I agree with you. You just need to add some caveats to your sweeping generalisations rather than scare the guy off.
Yes fusel alcohols are produced but they are always produced. The issue is whether it is detectable and fitting to the style.
These by-products are also produced early in the brewing process so not so relevant in this instance.
I don't know where you are going with the lager yeast tangent but I suggest you re-read the thread before throwing accusations around.

 

[Laurin]

That is what it says on the official Coopers website about the pale ale in the instructions section:

STEP 2: BREW
Ale yeast strains are generally the most reliable, fermenting quickly and effectively. The yeast supplied with this kit will give good results while fermenting with the commercial yeast culture will result in a beer even closer to intended style!

Although Ale yeast can ferment at very high temperatures (as high as 40°C), the closer the brew is to 21°C the cleaner the flavour and aroma.

ORIGINAL HERE


And this is what you find in the guide in how to harvest the yeast from Coopers beer bottles:

Coopers, encourage home brewers to use the yeast from naturally conditioned Coopers ales. The same ale strain is used across the range - Mild Ale, Pale Ale, Dark Ale, Sparkling Ale, Best Extra Stout and Extra Strong Vintage Ale.

ORIGINAL HERE


Hope this brings a bit of clarity into the discussion.

 

[graysalchemy]

Yes fusel alcohols are produced but they are always produced. The issue is whether it is detectable and fitting to the style.

Since when has fusal alcohols been fitting to a style? Fusal alcohols are recognised as an off or bad flavour in beer due to high temperatures, read any brewing literature on the subject and it will say that.

but would agree if you were using recovered yeast from their own pale ale which is probably more of a lager strain.

Since when has a larger yeast been used in a pale ale?

These by-products are also produced early in the brewing process so not so relevant in this instance.

Why is it not relevent? They don't get metabolised in the later stages of fermentation unlike diacetyls. The first 72 hrs of brewing is temperature critical as it is at this time that the yeast will metabolise unwanted by products. raising the temp to 21 - 22 can be a good thing after the main fermentation has finished in order to metabolise Diacetyls .

I can't see how my first reply was going to put the guy off, I was giving him facts that in actually what he was doing was correct.

 

[anthonyUK]

OK. A quick search found this from homebrew digest.
'Some of the higher esters (formed from fusel alcohols) have fruity traits which *are* desirable in many ale styles.' if not correct I bow to your experience.

Apparently Coopers use an lager yeast in their commercial pale ale which is why I mentioned it.

This is no longer constructive so I'll leave it there.

 

[graysalchemy]

Yes a fruity ester is desirable but not hot peppery fusal alcohols. The point about high temps is that the fusal alcohols don't get converted into anything else in the metabolism where as at lower temps any fusal formed do or can. Esters and fusal alcohols are not the same thing.

Finally acetaldehyde is a harmful by product causing organ damage and it is also a known carcinogen and as I cited increases significantly in high temperature fermentation.

If you hadn't jumped on my case demanding proof of my experience I may not have been so forked tongued with my responses.