Does fermentation temperature make a difference

[andydj]

Hi All,

So I'm into my 3rd brew, doing extract & partial mashes, loving it and getting great results so far and was just curious as to whether fermentation temperature makes a difference to flavour?
I understand an ale yeast for example has an operating temperature range say 15-20c and expect temperature will change the rate / speed of fermentation but would you get a different tasting beer if fermented at 15c to one fermented at 20c?

I have a brew fridge with STC temperature control so can set my fermentation temperature to whatever I wish, so given this choice wondered if it made a difference?

many thanks

Andy:

 

[brisboy]

Yes. It makes a big difference. Esters, sulphur, fussel alcohols etc. All affected by temperature.

 

[clibit]

Yes. It's a huge subject. Fermentation is where the art of brewing really lies. Some yeasts are affected more by temperature than others. English ale yeasts will, generally speaking, create very different flavours above 20C than below 20C.

 

[andydj]

So from what I've read over 20c is a bit of a no go area? So I'm guessing the only way to see the difference is to try the same brew at say 16c and again at say 20c?

Is a lower temperature likely to produce a "cleaner" taste and higher temperature something more fruity? for example?

 

[simon12]

So from what I've read over 20c is a bit of a no go area? So I'm guessing the only way to see the difference is to try the same brew at say 16c and again at say 20c?

Is a lower temperature likely to produce a "cleaner" taste and higher temperature something more fruity? for example?

Basically yes at lower temps the yeast ferments cleaner without adding as much flavour from the yeast. Best example is a lager yeast ferments at 10-12C ish and makes a crisp tasting larger.

 

[clibit]

You need to read up on a particular yeast. Above 20 not necessarily a no no.

 

[andydj]

Oh OK... more interesting stuff!
:geek:

 

[clibit]

You're at an early stage, probably best to explore recipes and address yeast nuances more fully later. But do check out a new yeast before you use it.

 

[rodabod]

You need to read up on a particular yeast. Above 20 not necessarily a no no.

This.

In the past, I've mistakenly brewed ale yeasts at 22c and it took months for the esters to subside. For me, I like a cool fermentation, so long as the yeast can handle it.

 

[andydj]

I guess like the other aspects of the recipe i.e. what malts, hop balance, %alc, the yeast plays an equal part in what is created and is down to personal preference.

thanks guys... as usual this place has been most helpful and a wealth of information

 

[TheRedDarren]

Yes, temperature during fermentation is very important to the final product.
It's been said that an kit Brewer with temperature control will turn out better beers than an ag Brewer without.

I'd echo what has been suggested above, at this stage keep things simple. Buy a liquid yeast after doing your research on it, think about: attenuation, esters, phenolics and suitability for the style of beer you're brewing.
Pitch the yeast direct from the packet.
After a few more brews think about yeast harvesting etc...

I've now got three yeasts in the yeast fridge, wlp500 Trappist yeast for Belgian beers. 005 which is for my British beers and 001 for American pa's and ipa's.

Making wort is only a part of making beer, the real money is in the fermentation.


Oh, also, buy 'Yeast' the book.
Indispensable!

 

[clibit]

Yeast plays a more significant role in some beers than others. Very broadly speaking, the American beers that we rave about tend towards more neutrality in terms of yeast, and tend to focus on their highly flavoured hops. English beers are much more determined by flavours created by the yeast, and by our top quality malts. Many strains of English yeast exist, and the best English beers are made by people who really understand the yeast they use. I have barely even started on this. Belgian beers are even more focused on yeast flavours, as well as the malts.The development of hops in America and down under has shifted the emphasis here towards hops, they can provide great flavours with very little yeast and malt profile, but variety is the spice of life. And not everyone likes big hop beer anyway.

 

[ericmark]

I, in error, bought a MH1210A intelligent temperature controller, instead of the STC 1000. Difference is mine will control heating or cooling not heating and cooling. I have a STC 1000 on order. Since in real terms I can only heat for last year the sensor has been wedged between a sponge and the fermentor wall and tests have shown this is within 1ºC of centre of brew temperature.

However also fitted an electronic thermometer to measure fridge air temperature and as it happens garage air temperature to try and work out the point where I will either have to stop brewing or use refrigeration as summer returns. The results were not as expected. Today as I write fridge air 16ºC and fermentor wall at 19.3ºC OK at moment new brew starting, but even at the end I can still get a couple of degrees between the two.

Form of heating has not helped, I use a demo under floor heating tile, which means direct contact heater to fermentor so heat goes into fermentor then heats the air. On a warm day when near ready to bottle fridge air and fermentor are at the same temperature, but at start of brewing or when garage is cold the difference increases.

The STC has not arrived yet so I have no idea as to the difference which can be set between heating and cooling so also have no idea what is required to ensure brew is at temperature required. I had all sorts of theories, but been proved wrong so will admit at the moment I simply don't know how to control. However one of my jobs was pre-heating and stress relief of pipes and I used many heaters, sensors, and controllers to do this mainly cooper heat so I do understand the problems with over shoot so realise and accept the controllers being used are not ideal. Commercial units would slowly alter the mark/space ratio so as it approaches the temperature required it starts switching off and on rather than wait until reached temperature before switching off. By using both heaters and coolers only just big enough we can get around the problem.

However what is does mean is measuring fridge air temperature does not mean the brew temperature is controlled. So it seems the normal way around the problem is to compensate for the error. So for my kit instructions state start temperature 20~25ºC and run temperature 18~24ºC and says an even temperature produces better results. This is for Young's harvest beers. From experience I have found too cool and it stalls and allows wild yeasts to get a hold and too warm gives it off tastes.

So I aim to start at 18ºC and over first 24 hours raise to 19.5ºC I know there is a 0.5ºC difference between fermentor wall and centre of the brew so that means brew is at 20ºC. After around 5 days I will raise to 20ºC on the controller as less heat is being produced by the fermentation and I want it finished in 20 days and ready to bottle. Instructions state between 5~10 days, I think I might get it in 10 days if I raised the temperature to 23ºC at fermentor wall. But I am allowing for temperature difference through the brew so keep to lower side.

If the brew is fermenting then wild yeasts will not get a hold, and once it has started getting too cold may delay bottling day, but will not harm the brew. Getting too hot however produces off tastes some which will reduce in time, but not all. It does not really matter what gauges show be it ºC or ºF or any other unit, since you need to compensate it's more down to keeping to a reading which will allow fermenting, but not too quickly. If my controller was measuring air temperature at the moment it would need to be set a 16ºC but since measuring fermentor wall temperature it is set to 19.5ºC.

It seems according to instructions we have 6ºC to play with, and my reading show about 4ºC between air temperature and fermentor temperature so between 18ºC and 20ºC air temperature will give between 18 ~ 24ºC brew temperature. So measuring air temperature in fridge heater on at 18ºC and fridge on at 20ºC should keep brew within limits set by manufacturers instructions.

But I tell the story as clearly it depends where your sensor is as to what temperature should be set.

 

[tucker1]

I presume some beers can vary?

The Black Roc Whispering Wheat said it was suited to warmer climates and recommended fermentation between 20c and 28c.

I thought that seemed a bit high.

 

[TheRedDarren]

I presume some beers can vary?

The Black Roc Whispering Wheat said it was suited to warmer climates and recommended fermentation between 20c and 28c.

I thought that seemed a bit high.

Many of the yeast strains tolerate different temperatures.
A lot of British style yeasts are happy between 18-20. Some of the Belgian strains like it above 20.
I've never used it but I believe a Mangrove Jack Workhorse is good up 30 ish (I think Myqul uses this so he may confirm).

But that's just the beginning. Any particular yeast will give different flavour profiles at different temperatures.
My Trappist yeast is very 'banana-ery' above 21~22, more spicy and less fruity below 19.
My 005 (ringwood) is full of Apple above 20 but much cleaner at 18.

This is why the advice is to select a strain and get to know it. It won't take you long to figure out if a) you like it and b) how to adapt you useage of it to change it to your requirements.

For me, it's the most fascinating part of brewing.

 

[TheRedDarren]

And another thing I haven't yet experimented with is changing the temperature during the fermentation.
A lot of Belgian brewers raise the temperature right up towards the end.

 

[mike77]

I've never bothered with temp control and have always brewed seasonally. In summer I use yeast that has a higher temperature range such as saison and brett. You get some interesting beers that way. As mentioned mangrove jacks workhorse claims up 30c. If i remember correctly I brewed with it at around 25c and don't recall any issues.

 

[mirsultankhan]

I guess like the other aspects of the recipe i.e. what malts, hop balance, %alc, the yeast plays an equal part in what is created and is down to personal preference.

thanks guys... as usual this place has been most helpful and a wealth of information

I was even reading that some brewers ferment quite cool and gradually increase the temperature near the end of fermentation to try to impart different esters and really make the yeast consume everything.

I see this has been mentioned already, should read the whole thread first, doh!

 

[MyQul]

I've never used it but I believe a Mangrove Jack Workhorse is good up 30 ish (I think Myqul uses this so he may confirm).

.

I've used the Workhorse yeast a couple of times but not when it was particularly warm. Over the summer I used mauribrew 514 English Ale. @the OP - This is a yeast similar to the Workhorse in that it can tolerate temps up to 30C (although the Workhorse claims it can tolerate temps slightly higher of up to 32C). The 514 definatley kicks out a lot of easters at 25C and above. I made a lot of stout over the summer and it has a strong dark fruit aroma - blackberry, dark plums etc and similar flavour but not so strong as the aroma.

 

[mike77]

I made a lot of stout over the summer and it has a strong dark fruit aroma - blackberry, dark plums etc and similar flavour but not so strong as the aroma.

Sounds good. Some people think that these types of flavours are a defect but I think it adds character. I drink ale rather than lager because it has more character.