pitching too high temperature?

[OldThumper]

Hi all,

My last few batches of beer have been ruined due to an over powering yeast flavour to them occuring very quickly at the end of fermentation. One thing I have identified is that I am impatient and I don't always get the beer down to around 20C before pitching my yeast (SO4 in this case). I usually turn off my immersion chiller when the wort temperature is around 30C - mainly because I am on a water meter and the last bit of cooling seems to take forever....I hate wasting good water!

So, my question is basically, will pitching the yeast in to wort which is somewhere in the region 25C to 30C ruin the final beer? (this problem occured on Nottingham and SO4)

I tasted the beer after about 6 days in to primary and it tasted fine and a bit hoppy (so, very promising). After 11 days in the fermenter all I can taste is a strong yeast flavour (not off flavours) and no hoppyness and little hop aroma - so it has deteriorated a lot, without doubt.

I ferment around 20C (but the initial 24 hours in to primary the wort slowly comes down from say 28C down to 20C)

I know fermenting at too high a temperature can give off flavours but this does not seem like "off" to me. The initial 24 hours will be high so is this short period (during which the yeast is multiplying and forming a head to protect the beer) enough to ruin the beer so quickly?

Thanks for any experiences/help guys!

p.s. I know from experience that the beer will not improve in time, even if it does clear over the coming weeks. The flavour is there to stay.

I am going to brew another batch and I will make sure the wort is around 20C before I pitch my starter, leaving it to the following day if necessary.

[Aleman]

That is one use of my FV Chiller . . . I can go from 31C to 12C (Doing a wheat beer) in less than an hour. There is no issue with pitching at 30C as long as you get it down to fermenting temperatures quickly . ..within an hour if possible.

[Deebee]

Hi all,

My last few batches of beer have been ruined due to an over powering yeast flavour to them occuring very quickly at the end of fermentation. One thing I have identified is that I am impatient and I don't always get the beer down to around 20C before pitching my yeast (SO4 in this case). I usually turn off my immersion chiller when the wort temperature is around 30C - mainly because I am on a water meter and the last bit of cooling seems to take forever....I hate wasting good water!

So, my question is basically, will pitching the yeast in to wort which is somewhere in the region 25C to 30C ruin the final beer? (this problem occured on Nottingham and SO4)

I tasted the beer after about 6 days in to primary and it tasted fine and a bit hoppy (so, very promising). After 11 days in the fermenter all I can taste is a strong yeast flavour (not off flavours) and no hoppyness and little hop aroma - so it has deteriorated a lot, without doubt.

I ferment around 20C (but the initial 24 hours in to primary the wort slowly comes down from say 28C down to 20C)

I know fermenting at too high a temperature can give off flavours but this does not seem like "off" to me. The initial 24 hours will be high so is this short period (during which the yeast is multiplying and forming a head to protect the beer) enough to ruin the beer so quickly?

Thanks for any experiences/help guys!

p.s. I know from experience that the beer will not improve in time, even if it does clear over the coming weeks. The flavour is there to stay.

I am going to brew another batch and I will make sure the wort is around 20C before I pitch my starter, leaving it to the following day if necessary.

Do you stir whilst chilling. It speeds things up drastically i have found.

[fullclaret]

Completely agree with deebee, gentle stirring makes a huge difference. I first noticed it when I touched the exit water and found it to be very cold despite the wort temp being approx 50oC. A quick stir later and it exitted warm.

Depending on the yeast some will die above 25oC, so I would expect the final ferment to be less complete than expected, possibly with some flavour impact. You do need to start around 20oC for most yeasts to avoid a delayed start though.

Another thing to note is that above 25oC / 80oF introducing oxygen will cause some oxidation which could lead to off-flavours developing later on.

Cheers,
FC

[gnorwebthgimi]

"Another thing to note is that above 25oC / 80oF introducing oxygen will cause some oxidation which could lead to off-flavours developing later on."

I assume you are referring to Hot Side Aeration.

I thought I had a Hot Side Aeration issue due to my mash procedure and tried to eliminate this. I altered my mash procedure to eliminate exposure to air thinking host side aeration occurs at hot temperatures like the mash temperature.

I cooled my wort to 28-30'c before aerating and picthing the yeast and it fermented and tasted fine until a week after barrelling when it lost it's body and flavour. I suspect that this has more to do with mash temperature or infection rather than HSA.

I later read that Hot Side Aeration is optimum at about 32'c, which isn't exactly "hot" at all?!

What are your thoughts on this Fullclaret?

[Eric]

You need oxygen in the wort at the beginning of fermentation else your yeast will struggle to grow and multiply.
I wouldn't have thought 30C was too high, a slightly higher temperature is possibly beneficial for good quick start as long as it doesn't stay there.
Yeast taste? Is it? I'll frequently drink beer with yeast in it without great objection and thus wonder if this is your problem. It's a long long time since I've tasted beer from the FV and it amazes me how beer flavours vary day to day during conditioning.

[dave-o]

I have pitched quite far above normal temperature and not had any problems. Perhaps i've been lucky on those occasions.

[Aleman]

You need oxygen in the wort at the beginning of fermentation else your yeast will struggle to grow and multiply.

Actually no. You need oxygen (and a source of sterol eg lipids) for yeast to create a reserve of ergosterol, to allow it to grow new cell wall when they bud . . . however the majority of dried yeasts already have this reserve of Ergosterol when you pitch and will reproduce and ferment well with no further aeration at all (Wet yeasts are a different story) . . . I have concerns about S-04, and in the past it has been known to stop fermenting early unless it is aerated before / during pitching . . . but other strains from DCL don't exhibit that behaviour.

If you are repitching your yeast, in order to build the ergosterol reserve for the next fermentation, then you must aerate before/during pitching otherwise subsequent fermentations will be poor.

However, aerating before fermentation will do no harm . . . and I know some commercial breweries that use air injected into the hot wort 990+C) on the way to the plate chiller to do this. . . . their beer does not show signs of oxidation during it's normal lifetime.

Hot side aeration is a condition that is related to poorly malted barley containing high levels of lipids (generally US 6 Row), that did not eliminate the HSA precursors. UK 2 row barley is significantly lower in these precursors and therefore it is extremely unlikely that any UK brewer will experience it. . . . I've encountered one case in the last 20 years here in the UK

[OldThumper]

Thanks for the input guys. But, has anybody experienced what I am suggesting? What else can cause the beer to go from "nice tasting in 6 days" to "very yeasty and loss of hop flavour in 11 days or so"? I will tip this batch away I think.

I have made many many cracking brews but most have been in the winter months when the wort will have cooled to a much more sensible temperature I think. The only part of the process which I do kind of rush on is the cooling + yeast pitching.

The one way to find out is to get on brew another!

[gnorwebthgimi]

I'm having a similar issue according to time frame, but my beer loses the hop taste and just tastes a bit naff (which I described as sour but like lemons):

viewtopic.php?f=2&t=35444

I think my beer is fermenting all the residual sugar out, either because my mash temp is too low or a wild yeast has got in (called a gusher infection).

Don't chuck the beer, try and get as much information from it as possible first.

Take a sample and degas it then measure the gravity, if it's low could be similar to my issue.

I doubt that fermentation temperature caused this as it shouldn't taste nice then go bad. If anything it should taste bad then get better as the yeast cleans the beer.

Keep us posted.

[techtone]

I''m another who has pitched just on the high side of 25 degrees and no problem at all. Not sure if It has been mentioned but is the beer clearing fully i.e. is getting cold enough (or long enough) after fermentation to cold condition. ( I know you said it starts ok so I'm probably not helping )

[OldThumper]

Yes, it is clearing. I just tasted a few mouth fulls and it is definitely bad. Most odd. I am pretty certain it is not an infection as surely that would be vinegary and you would smell it. This smells neutral to bland and the taste is probably something like eating the sludge from the bottom of the fermenter mixed with beer. It has been sat in the cool garage for the last 4 days so is in a prime conditioning location.

Answering another question - I do stir a little but I certainly don't stand there for 30 mins doing it. I think I will stir more as yes indeed it does make a difference. Putting my thermometer in different spots in the wort gives considerably different temperature readings.

I just took a SG reading and it reads about 1.08, so about normal

I am brewing tomorrow so I will make sure everything is spotlessly sterilised and that I pitch as close to 20C as I can (using SO4 again).

[boingy]

Seems a shame to tip it. Can you not find it in your heart to keg it for a month or two, just to give it one last bite of the cherry?

[Blackjack]

Dried yeast, I think you said S-04, is bottom working and does not leave a protective crust after the ferment finishes so air can get at the finished beer. Also if you pitch on the warm side such a yeast, as aleman suggests, can get cracking quite quickly and is also reasonably temperature tolerant. The prinicpal ferment can be over and done with in as little as 24 hours, but only generally up to 3 days or so.

Allowing a further couple of days for the yeast to tidy up and some conditioning and settling to take place then 6 days total is about the right time to rack it off. Brew on a Sunday and rack the following Saturday for instance, at which time you say it tastes lovely. Leaving it in the FV for 11 days for ordinary 4.5% or so middle of the road british bitter is on the long side.

As aleman suggests, hot side aeration is just a ghost story to frighten children.

I now have my larger FV in a very well insulated enclosure and a I use an immersed digital thermometer probe ( An old Paterson photographic darkroom device which is good to 1/10 degree, they were not expensive, but don't know whether still manufactured. Theyre not needed for digital ) and the yeast while working generates so much heat I have to allow air currents to keep the FV down to about 20C. It is all in a cold barn and when I see the temperature drop away from 20C down to around 15C I know that work has stopped and I give it two more days before I test the gravity and rack it off.

[OldThumper]

I read in John Palmer's "How to Brew" that aerating the wort when it is still warm/hot (above 27C or so) can easily oxidise the beer. If this is the case then I guess you need to be careful stirring the wort to cool it down during the immersion chiller stage?