Yeast and kit temperature

[Jai]

Hello.

I made my 2nd beer kit yesterday, Festival Landlord. I got the temperatures a bit warm, mainly due to using mineral water which was already room temp and hot water (3l as suggested an more to clean out malt bags). So I waited a while and pitched the yeast (straight in the fv) at about 28 deg.

I was wondering if I did the right thing, is it worse to wait longer or pitch warmer? Will the yeast no ok at that temp?

Thanks

 

[graysalchemy]

You are best to let it cool to about 21c especially now as temps are warming up. Yeast when it starts growing is exothermic so it will produce heat, and if you brew warm ie above 22c especially in the initial phases you can get fusal alcohol production which is reputed to cause hangovers but also a solventy taste to the beer.

Keep your temps down.

However when you do extract or AG brewing and you are transfering from the boiler to the fv I usually stop chilling at about 28c as you lose about 7-8c in dropping it into the FV.

Try keeping it on a cold concrete floor garages are excellent the concrete acts as a heat sink and cools the beer. :thumb:

 

[ScottM]

Pitching a bit warm is fine, as long as the temp is coming down it won't be an issue :)

 

[mikeyjay84]

Its not ideal i guess. I was brewing last night and after leaving FV outside for 30 mins managed to get it down to 27 and pitched as it was midnight and i could not stay up longer.

I pitched at the same temp a few weeks back on a coopers lager. Everything worked out fine, after 24 hours there was some nice foamy frothiness going on so keeping fingers crossed for last nights batch. I should've monitored everything better as i was adding water - but to be honest, so many things were going wrong (can opener failing, lacerated fingers) that i kinda didnt pay attention too well. I've renamed the milestone crusader to the "Bloody Crusader" now in honour of my battered fingers!

I deffo won't be pitching so high next time.


Hope someone more experienced can shed a little light on what could happen if pitching yeast at this temp??

 

[graysalchemy]

Question

Hope someone more experienced can shed a little light on what could happen if pitching yeast at this temp??

Answer

Yeast when it starts growing is exothermic so it will produce heat, and if you brew warm ie above 22c especially in the initial phases you can get fusal alcohol production which is reputed to cause hangovers but also a solventy taste to the beer.

 

[mikeyjay84]

Pitching a bit warm is fine, as long as the temp is coming down it won't be an issue :)

My kitchen seems to be in a permanent 20-21 degree state most of the time. Brew temp usually levels out about there.

 

[mikeyjay84]

Question

Hope someone more experienced can shed a little light on what could happen if pitching yeast at this temp??

Answer

Yeast when it starts growing is exothermic so it will produce heat, and if you brew warm ie above 22c especially in the initial phases you can get fusal alcohol production which is reputed to cause hangovers but also a solventy taste to the beer.

Thanks! :thumb:

 

[ScottM]

Nothing to worry about.

Pitching high isn't an issue (within reason), as long as the temp is coming down and will do over the next couple of hours. Fermenting at high temps is where the dangers lie.

When you pitch the yeast it will start to multiply and colonise. This can take anywhere from hours to days (depending on temp, pitching rate, etc). Your wort is effectively an incubator during this time so being a few degrees high won't do any harm at all.

Once the yeast has multiplied/colonised they will set to work on the sugars. At this point the temp is a lot more important as if it's to warm or too cold they will get unstable and start producing esters etc. It's at this point that you need everything at a steady, controlled temperature.

 

[graysalchemy]

As long as your wort remains at 20-21 then it will be fine however wort temp and air temp are two different things, especially at the begining because of the exothermic nature of fermentation. If you are having dificulty getting temps down standing in a container of cold water and draping a wet towel over the fv will help as well and if things get really bad put a fan on to aid latent heat of evaporation and thus cooling.

Fermenting at high temps is where the dangers lie.

And that is where the problem is pitching at high temps often results in the temp never getting down as the yeast gets going quicker and thus produces its own heat especially in summer time. Trust me been there and had to throw the brew away. :evil: :evil:

:thumb:

 

[mikeyjay84]

Thanks all.

I should be home around 4pm today, will check in on the FV. If its not dropping quickly enough, i will wrap a towel around it and shove it into a sink of cold water. Hopefully that will bring it down a little.

My last brew sat at around 21 degrees for the entire time, although it took about 48 hours to drop to that level.

 

[ScottM]

Fermenting at high temps is where the dangers lie.

And that is where the problem is pitching at high temps often results in the temp never getting down as the yeast gets going quicker and thus produces its own heat especially in summer time. Trust me been there and had to throw the brew away. :evil: :evil:

:thumb:

If the temp doesn't come down then there could be an issue, but pitching at that temp isn't a problem. The exothermic reaction will be there regardless of pitching temp and the stabilised temperature will be based on the outside temp rather than the temp pitched at.

I was focusing on the pitching temp, I do agree that the op will probably have issues with keeping the temps stable though (given the room temp to begin with). Those issues would be there regardless of pitching at 21 degrees or 27 though.

 

[graysalchemy]

My last brew sat at around 21 degrees for the entire time, although it took about 48 hours to drop to that level.

Within 48 hrs your yeast will be multiplying big time and this is the critical time for ester and unfortunately fusel precursor production.

 

[ScottM]

Thanks all.

I should be home around 4pm today, will check in on the FV. If its not dropping quickly enough, i will wrap a towel around it and shove it into a sink of cold water. Hopefully that will bring it down a little.

My last brew sat at around 21 degrees for the entire time, although it took about 48 hours to drop to that level.

I wouldn't leave it that long personally. The first 48 hours is generally within the time the yeast hit their stride and will be doing their thing. If the temp wasn't down within a couple of hours I would be taking measures to lower it.


Edit: Yeah that ^^

 

[Hawks]

The cooler temps are needed in the intitial phases, in an ideal world you would pitch at a slightly lower temperature ( 1 or 2 c lower ) and let it warm slowly to your planned fermentation temperature. Yeast find a 2C change in temp a HUGE change as they are fussy little blighters. Most of the flavour compounds are created in the initial 48 - 72 hours, so this is the vital time to keep the temps right, after that you can turn the temps up slightly to keep the yeast active and help it clear up.

You may well get away with it, but you'd be better off leaving overnight to cool down more than risk pitching at such a high temp.

 

[anthonyUK]

The cooler temps are needed in the intitial phases, in an ideal world you would pitch at a slightly lower temperature ( 1 or 2 c lower ) and let it warm slowly to your planned fermentation temperature. Yeast find a 2C change in temp a HUGE change as they are fussy little blighters. Most of the flavour compounds are created in the initial 48 - 72 hours, so this is the vital time to keep the temps right, after that you can turn the temps up slightly to keep the yeast active and help it clear up.

You may well get away with it, but you'd be better off leaving overnight to cool down more than risk pitching at such a high temp.

There are a lot of assumptions being made about the type of yeast, amount etc.
I have read from a number of sources that pitching at the higher temperature range is fine as long, as ScottM mentioned, the wort is in the process of being cooled.
I'm guessing this is OK IF you are pitching a starter which contains 100% viable cells of the required amount (~200billion).
For dry yeast, rehydrated or not it will be different.

To be on the safe side it would be better to pitch at a temperature within the acceptable fermentation range although Wyeast have this to say:

Lagers: 46°F – 58°F (8°C – 14°C) *Note: Lager fermentations can be started warmer (~60°F, 15.5°C) until signs of fermentation (gravity drop, CO2 production, head formation) are evident. Cool to desired fermentation temperature once signs of fermentation are observed.

So I'm guessing not much flavour compounds are produced during the growth phase or they would be apparent in a Lager or that temperature increase is not enough to matter.
None that are not able to be removed later in the ferment anyway.


BTW - If you want to see how the Aussies discuss yeast have a look here for an 'entertaining' read - http://aussiehomebrewer.com/topic/72453 ... h-in-pack/

Th

 

[mikeyjay84]

The cooler temps are needed in the intitial phases, in an ideal world you would pitch at a slightly lower temperature ( 1 or 2 c lower ) and let it warm slowly to your planned fermentation temperature. Yeast find a 2C change in temp a HUGE change as they are fussy little blighters. Most of the flavour compounds are created in the initial 48 - 72 hours, so this is the vital time to keep the temps right, after that you can turn the temps up slightly to keep the yeast active and help it clear up.

You may well get away with it, but you'd be better off leaving overnight to cool down more than risk pitching at such a high temp.

There are a lot of assumptions being made about the type of yeast, amount etc.
I have read from a number of sources that pitching at the higher temperature range is fine as long, as ScottM mentioned, the wort is in the process of being cooled.
I'm guessing this is OK IF you are pitching a starter which contains 100% viable cells of the required amount (~200billion).
For dry yeast, rehydrated or not it will be different.

To be on the safe side it would be better to pitch at a temperature within the acceptable fermentation range although Wyeast have this to say:

Lagers: 46°F – 58°F (8°C – 14°C) *Note: Lager fermentations can be started warmer (~60°F, 15.5°C) until signs of fermentation (gravity drop, CO2 production, head formation) are evident. Cool to desired fermentation temperature once signs of fermentation are observed.

So I'm guessing not much flavour compounds are produced during the growth phase or they would be apparent in a Lager or that temperature increase is not enough to matter.
None that are not able to be removed later in the ferment anyway.


BTW - If you want to see how the Aussies discuss yeast have a look here for an 'entertaining' read - http://aussiehomebrewer.com/topic/72453 ... h-in-pack/

Th

All good and helpful info. Thanks! I can see how confusions can come about quite easily. Before my first ever brew, i was following coopers instructions - normal right? You get a kit, you follow the instructions. I also did a hell of a lot of research here on THBF and other places. Why would coopers suggest that:

NOTE: The supplied yeast can ferment at 18°C-32°C. However, the yeast will perform at it’s best when the temperature is between 21°C-27°C. If the temperature is allowed to drop too low fermentation activity will stop.

Unless you do a fair amount of background reading, you could potentially pitch around 29-32 degrees and leave your fv at 25 degrees and not know any better. After all you are doing what the guidelines say.

I guess this is why there are so many assumptions right? Thank god for THBF and other sites where we can be enlightened by experienced brewers.

 

[Hawks]

I have made an assumption that it's an ale yeast due to the temps we are discussing ( and the fact that it's a kit which also suggests it will be an ale yeast ). I have also assumed that the correct amount of yeast is being pitched.

Whilst it is OK to pitch slightly higher as long as its cooling, pitching slightly lower ( say 19c ) would be the IDEAL temp to pitch the correct amount of yeast with it slowly coming up to 20c over the next day as fermentation starts. Then maintain this for most of the ferment, as it slows raise the temps up to 21c to compensate for the yeast slowing down and help with the clear up process. Again, this is all based on ale yeasts and is a bit of a generalisation as some ale yeasts can take higher temps ( I have not yet used lager yeasts so not looked into such detail for them ).

The warmer the temps, the faster the growth cycle which leads to increased exothermic activity and also the precursors to flavours and compounds that are not desirable, some of which cannot be cleared up later. Ale yeast will grow at its fastest at just over 30C IIRC, but this is certainly not a temp you want to be fermenting at.

For anyone wanting more detail I recommend the yeast book by Chris White and the man whose name I always forget ( starts with a Z though ) :thumb: It's a bit heavy going in places, but there is a lot of very good and detailed information in there including showing the different compounds created by fermenting at temperatures with just 5c difference.

 

[graysalchemy]

+1 for what hawks says that is sound advice and practice why bother risking it just for the sake of waiting a few hrs.

 

[graysalchemy]

So I'm guessing not much flavour compounds are produced during the growth phase or they would be apparent in a Lager.
None that are not able to be removed later in the ferment anyway.

Oh yes they are all your esters and fusals are produced or at least the precursors are produced during the growth phase it is the most important stage in the development. But this occours in the higher end of fermentation temps fusels 20 -21c and fusels 22-23c+.

So you won't get them in lagers and also why scottish ales are traditionally brewed at below 19c to avoid esters.

 

[Jai]

Impressive amount of discussion in such a short time! Good stuff.

So basically whilst it's not ideal it should turn out ok. I did it last night and this morning it was 22deg, so not too high.