Butterscotch Lager - DOH!

[Tricky Micky]

Just after a bit of feedback here.

My latest Lager - a really simple recipe has got a distinct butterscotch taste to it at the 3 week point of its secondary fermentation in the bottle. I've done this one before now and never had this issue before.

Coopers OS Lager Kit 1.7kg

Coopers Liquid Malt   1.5kg

300grams Dextrose

150g Maltodextrin

Dubbya Dry Yeast 15 grams

According to my notes Ferment temp was @ 12 degrees, Diacetyl rest after FG established for 2 days @18 degrees C - and CC for 5 days @ 1 deg C.

All previous lager batches using Dubbya I've pitched 11grams of the dry yeast with the wort @ 20 degrees. In the past I've then placed the FV in the temp controlled fridge and set the temp for 12 degrees C.

All previous batches (Lager) have had the 2 day diacetyl rest @ 18 degrees.

What I did do differently to all my other Lagers with this latest batch was to initially set the temperature for the FV in the Temp controlled fridge @ 18 degrees C and held that constant for the first 24 hours before reducing the temp to 12 degreesC. All the other batches were fermented from the outset @ 12 degrees C.

 

Could this be the reason I have diacetyl in the beer and if so Will aging improve the taste? 

Edited July 19, 2021 by Mickep

[iBooz2]

2 hours ago, Mickep said:

All previous lager batches using Dubbya I've pitched 11grams of the dry yeast with the wort @ 20 degrees. In the past I've then placed the FV in the temp controlled fridge and set the temp for 12 degrees C.

What I did do differently to all my other Lagers with this latest batch was to initially set the temperature for the FV in the Temp controlled fridge @ 18 degrees C and held that constant for the first 24 hours before reducing the temp to 12 degreesC. All the other batches were fermented from the outset @ 12 degrees C.

Could this be the reason I have diacetyl in the beer and if so Will aging improve the taste? 

G'day Mick, I reckon two things (or combination of both) may have been the cause of the issue.  1. Only one 11.5 g pack of yeast is not enough.  It may be ok for a standard gravity 10 - 11 L batch but I always pitch 2 x 11.5 g sachets for 23 L ones if using the dry yeast.  If using reclaimed trub I tend to over do it with that too.  2.  Cooked too warm too quick, I always pitch mine low to start off say around 10 C then bring it up to 12 C for about 7 days then up the temp for the D-Rest.  I have a chart on my other PC will post up of my W-34/70 temp profile later for you.

I think you may have just over stressed your yeast a bit much (not enough + too warm) so you have ended up with these flavours.  Can also be an infection too but I reckon best guess is my #1 or #2.  How did the bottling process go?  Did not introduce too much O2 in the bottling process did you?

Edited July 19, 2021 by iBooz2

[Tricky Micky]

Just now, iBooz2 said:

G'day Mick, I reckon two things (or combination of both) may have been the cause of the issue.  1. Only one 11.5 g pack of yeast is not enough.  It may be ok for a standard gravity 10 - 11 L batch but I always pitch 2 x 11.5 g sachets for 23 L ones if using the dry yeast.

Thanks for the feedback mate, just to be clear all my other lagers have been pitched with 11grams of dubbya and have not had the off flavor. It may improve slightly with age in the bottles I guess

This latest batch, the one in question I used 15grams of Dubbya (Dry Yeast sprinkled). Hadn't used reclaimed trub yet in any of my brews.

I don't know where I'd read or saw the info on pitching at that temp and holding it for the first 24 hours but this is the only time I've done that. I should've also mentioned that the volume was @23litres.

I don't think it's an infection there was no indication at least to my eye that the batch was infected with anything - looked and smelled normal while in the FV. But I'm no expert.

Thanks again for the feedback Boozer.

[iBooz2]

2 minutes ago, Mickep said:

Thanks for the feedback mate, just to be clear all my other lagers have been pitched with 11grams of dubbya and have not had the off flavor. It may improve slightly with age in the bottles I guess

I don't know where I'd read or saw the info on pitching at that temp and holding it for the first 24 hours but this is the only time I've done that. I should've also mentioned that the volume was @23litres.

Probably unlikely to improve.  Is it cloudy?  You could throw in some brett yeast and let it eat the problem and create some sour beers.

Yes Dubbya will work at the higher ale temps, that why I think it may have gone nuts too quick and ended up a hurried ferment.  I always pitch em low and slow, seem to taste much cleaner that way.  Our friend @Graubart is a bit Dubbya fan so he will have an opinion on his pitching rates and temps that may help for your next lager

[Journeyman]

Maybe you were lucky on the other brews? Butterscotch being diacetyl flavour, I thought the normal 'rest' was just a few degrees above ferment - could 6° higher be too much and the yeast didn't clean up properly?

Fermentis say 10° - 15° for 34/70 (which I presume is 'dubbya?) so maybe holding it high for that time stressed it and it didn't really recover enough to deal with diacetyl?

[Pickles Jones]

3 hours ago, Mickep said:

What I did do differently to all my other Lagers with this latest batch was to initially set the temperature for the FV in the Temp controlled fridge @ 18 degrees C and held that constant for the first 24 hours before reducing the temp to 12 degreesC. All the other batches were fermented from the outset @ 12 degrees C.

The W-34/70 packet says a fermentation temperature: 19-22C ideally 12-15C . There is a school of thought that considers that the 22C is to high for this yeast but this of course is not what Fermentus would say!

I think that holding the temperature at 18C for 24hrs at the beginning then bringing down may have contributed to the problem at hand. As the brew would have been around 18C for more that 24Hrs

For what it's worth, I do similar to you. I put the FV in the fridge at around 18C (only because that's temperature I end up with, not mixed to that temp)

which is set at 12C. This will bring the temperature down to 12C overnight and it stays there until it's time for D/Rest.

I don't think there is much that done with your brew other than leaving it for a while and see what happens.

 

 

[Tricky Micky]

2 hours ago, iBooz2 said:

Probably unlikely to improve.  Is it cloudy?  You could throw in some brett yeast and let it eat the problem and create some sour beers.

Yes Dubbya will work at the higher ale temps, that why I think it may have gone nuts too quick and ended up a hurried ferment.  I always pitch em low and slow, seem to taste much cleaner that way.  Our friend @Graubart is a bit Dubbya fan so he will have an opinion on his pitching rates and temps that may help for your next lager

Nup, clean as. Looks great, has a good head just the butterscotch taste - Doh!

I don't know why I changed anything really just read somewhere here (I think)  to start warmer and then reduce down to ferment temps.... Live an learn hey

[Tricky Micky]

2 hours ago, Journeyman said:

Maybe you were lucky on the other brews? Butterscotch being diacetyl flavour, I thought the normal 'rest' was just a few degrees above ferment - could 6° higher be too much and the yeast didn't clean up properly?

Fermentis say 10° - 15° for 34/70 (which I presume is 'dubbya?) so maybe holding it high for that time stressed it and it didn't really recover enough to deal with diacetyl?

All the other brews and there's a heap of them were brewed the at the same temp. The only difference with this one is I held the temp control at 18 degrees initially  for 24 hours before dropping to 12 degrees.  I also used 4 grams more yeast in this batch (15g instead of 11g in the brew)

I think you and Boozer might be onto it  - I may have stressed the yeast at the beginning and it didn't behave in the same way at the end of the ferment when doing the D - Rest.

Hoping a bit of time in the bottle might help. Thanks for the feedback JM.

 

[Tricky Micky]

46 minutes ago, Pickles Jones said:

The W-34/70 packet says a fermentation temperature: 19-22C ideally 12-15C . There is a school of thought that considers that the 22C is to high for this yeast but this of course is not what Fermentus would say!

I think that holding the temperature at 18C for 24hrs at the beginning then bringing down may have contributed to the problem at hand. As the brew would have been around 18C for more that 24Hrs

For what it's worth, I do similar to you. I put the FV in the fridge at around 18C (only because that's temperature I end up with, not mixed to that temp)

which is set at 12C. This will bring the temperature down to 12C overnight and it stays there until it's time for D/Rest.

I don't think there is much that done with your brew other than leaving it for a while and see what happens.

 

 

 

"I think that holding the temperature at 18C for 24hrs at the beginning then bringing down may have contributed to the problem at hand. As the brew would have been around 18C for more that 24Hrs"

PJ thanks for the feedback mate, I do think that you are correct.  I won't be doing this again!

[RDT2]

35 minutes ago, Mickep said:

 

"I think that holding the temperature at 18C for 24hrs at the beginning then bringing down may have contributed to the problem at hand. As the brew would have been around 18C for more that 24Hrs"

PJ thanks for the feedback mate, I do think that you are correct.  I won't be doing this again!

I’ve done a few pilsners with one packet of W34/70 using the technique of holding at 18 for the first 24hrs then lowering the temp to 12 after yeast has cranked up with no noticeable ill effects. I did have one that was a bit sulphurous but that disappeared after couple of weeks and turned out to be a great beer. Whilst using this technique I never had a starting gravity over 1048

  though, not sure what yours would be probably more. I now make starters though but have only done that with S189 so far nice beer but have one in the fermenter now cold crashing with W34/70 be interesting to see the difference???

[jamiek86]

from my experience the sulphur smell.amd taste doesn't go away until over 3 months or conditioning and sometimes not at all. ever since started using carbon filter and actually didn't rinse after stellar San I have noticed it's gone away. I was also pitching at 18 degrees and dropping down but now pitch cold. along with filtered water I have done 2 in row with out the sulphur smell and taste. it could how ever be random and none of this a cause at all. sorry can't offer anything conclusive but maby just adjust a few things yourself and see if this comes good.

[iBooz2]

@Mickep  Just went through all my brew notes for my lagers over last two year and all but two were started low (the first two) but I did not make any tasting notes back then so unsure if any difference to a high temp yeast start but I certainly would have noticed if butterscotch and I don't remember any and would have made a big texta note on my brew sheet if there was any.

Because I brew low and slow with my lagers I also do not notice too much sulfur smell with Dubbya.  I did one batch with S23 and my wife would not believe me that it was not me farting in the brewery.

On all my Dubbya batches always did the D-Rest up at 18 C.  See my own adopted W-34/70 fermentation temperature profile over on the yeast thread which is what I use religiously now for this yeast.  Note the absolut max / mins and ideal fermentation temps on the chart.

I work on a 21 day cycle for my lagers.  Am still working on a profile for Diamond Lager Yeast and Copenhagen Lager Yeasts and will work out what works for me and post up when I am happy with the several brews that I have made this lager season.  So far the pitch low and slow and 21 days is working on those yeasts as well going by the current drinking and taste of the Cals Pils  - very happy.  

My yeast packs have the temp ranges as per pic below.

Edited July 19, 2021 by iBooz2

[jamiek86]

@iBooz2 is that 21 days in fermenter or between pitch to keg and gas? I'm finding I'm doing ddocel rest in less than week if going by gravity. 3 days if using repitched slurry that takes off like rocket. maby I need to slow it down a bit. still only brewing at 12 degrees but chomps through gravity fast.

In comparison I have some brews with fresh pack of US05 take off and get to gravity slower at 18 degrees.

Edited July 19, 2021 by jamiek86

[Tone boy]

Hey @Mickep sorry to hear about your troubles. I reckon @ChristinaS1 Christina is another one who will be able to answer your questions as she is very knowledgeable on this subject. 

I have never had butterscotch in my lagers but from what I understand it is diacetyl which is the culprit here. I have a similar process to you with lagers, where I pitch the dry yeast or yeast slurry of 34/70 at 18 degrees. However I don’t hold that temp - I stick it in the brew fridge where is slowly cools down to 12 degrees. At the end of fermentation I bring it back up to about 18 degrees for 3 days before CC - which I just do quickly, not slowly like some do. 

How fresh was the yeast package? If you used 15g was it 11g from 1 pack and 4g from somewhere else? Just wondering if the yeast was stressed or out of date at the start…sometimes it may be kept warm at a couriers warehouse over a weekend…Perhaps it is not the process that is to blame here - not sure…

Maybe a longer D rest? But then again it has worked for you in the past…

[Tricky Micky]

41 minutes ago, Tone boy said:

Hey @Mickep sorry to hear about your troubles. I reckon @ChristinaS1 Christina is another one who will be able to answer your questions as she is very knowledgeable on this subject. 

I have never had butterscotch in my lagers but from what I understand it is diacetyl which is the culprit here. I have a similar process to you with lagers, where I pitch the dry yeast or yeast slurry of 34/70 at 18 degrees. However I don’t hold that temp - I stick it in the brew fridge where is slowly cools down to 12 degrees. At the end of fermentation I bring it back up to about 18 degrees for 3 days before CC - which I just do quickly, not slowly like some do. 

How fresh was the yeast package? If you used 15g was it 11g from 1 pack and 4g from somewhere else? Just wondering if the yeast was stressed or out of date at the start…sometimes it may be kept warm at a couriers warehouse over a weekend…Perhaps it is not the process that is to blame here - not sure…

Maybe a longer D rest? But then again it has worked for you in the past…

Cheers TB,

 

19 hours ago, iBooz2 said:

 

 

[Tricky Micky]

19 hours ago, iBooz2 said:

@MickepJust went through all my brew notes for my lagers over last two year and all but two were started low (the first two) but I did not make any tasting notes back then so unsure if any difference to a high temp yeast start but I certainly would have noticed if butterscotch and I don't remember any and would have made a big texta note on my brew sheet if there was any.

Because I brew low and slow with my lagers I also do not notice too much sulfur smell with Dubbya.  I did one batch with S23 and my wife would not believe me that it was not me farting in the brewery.

On all my Dubbya batches always did the D-Rest up at 18 C.  See my own adopted W-34/70 fermentation temperature profile over on the yeast thread which is what I use religiously now for this yeast.  Note the absolut max / mins and ideal fermentation temps on the chart.

I work on a 21 day cycle for my lagers.  Am still working on a profile for Diamond Lager Yeast and Copenhagen Lager Yeasts and will work out what works for me and post up when I am happy with the several brews that I have made this lager season.  So far the pitch low and slow and 21 days is working on those yeasts as well going by the current drinking and taste of the Cals Pils  - very happy.  

My yeast packs have the temp ranges as per pic below.

 

Thanks Boozer,

I'll go back to my original lager process and take a few tips from here as well. I think the D rest I've been doing so far marries well with all the material on the subject so I'm comfortable with that end of things. I definitely will pitch cooler from now on and certainly will not be fermenting high ever again for the first day or so as I've done with this latest brew.

I've been fermenting @ 12 degrees and this has worked for me in the past. The more I think about it the more it's likely that the off flavour was caused from the initial ferment temp of 18 degrees C.   Anyway onward and sideways 

[Otto Von Blotto]

In my experience pitching a heap of yeast at or below ferment temp produces a better result than pitching less yeast at a warmer temp then bringing it down after 12/24 hours or whatever. I have pitched lagers warmer and dropped them straight away but it's not my preferred method.

The problem sounds like diacetyl, the temperature of the rest is fine at 18, but it may not have been long enough. I do all mine at 18 but they sit there for about a week before I begin the drop to lagering temps, just to make sure it's done properly. 

[Tricky Micky]

1 hour ago, Otto Von Blotto said:

In my experience pitching a heap of yeast at or below ferment temp produces a better result than pitching less yeast at a warmer temp then bringing it down after 12/24 hours or whatever. I have pitched lagers warmer and dropped them straight away but it's not my preferred method.

The problem sounds like diacetyl, the temperature of the rest is fine at 18, but it may not have been long enough. I do all mine at 18 but they sit there for about a week before I begin the drop to lagering temps, just to make sure it's done properly. 

Thanks OVB - I've been doing a 3 day D rest for my lagers but maybe the warm start to the ferment for the first time influenced the D rest at the end. I don' t know.  I'll pitch cooler, D_rest for a bit longer and see how that goes.. Thanks heaps for the feedback mate.

[Tricky Micky]

2 hours ago, Mickep said:

3 hours ago, Tone boy said:

Hey @Mickep sorry to hear about your troubles. I reckon @ChristinaS1 Christina is another one who will be able to answer your questions as she is very knowledgeable on this subject. 

I have never had butterscotch in my lagers but from what I understand it is diacetyl which is the culprit here. I have a similar process to you with lagers, where I pitch the dry yeast or yeast slurry of 34/70 at 18 degrees. However I don’t hold that temp - I stick it in the brew fridge where is slowly cools down to 12 degrees. At the end of fermentation I bring it back up to about 18 degrees for 3 days before CC - which I just do quickly, not slowly like some do. 

How fresh was the yeast package? If you used 15g was it 11g from 1 pack and 4g from somewhere else? Just wondering if the yeast was stressed or out of date at the start…sometimes it may be kept warm at a couriers warehouse over a weekend…Perhaps it is not the process that is to blame here - not sure…

Maybe a longer D rest? But then again it has worked for you in the past…

Don't know what happened to my previous response mate but it was shortened to just Thanks TB, 

The yeast was fresh, I used 3 packs of 10grams split between two FV's at volume 23 liters. I think as OVB said a longer D rest, and I'll pitch much cooler in future. I might also go for the cooler ferment temp as well - 10 degrees.

 

[ChristinaS1]

@Mickep I agree with Kelsey's diagnosis of diacetyl and that it would be a good idea to leave it at D-rest temp for a week. AFAIK a two day D-rest is a minimum, not a maximum. 

If you are going to use one package of dry yeast and pitch warm, to get your cell count up, you have to be sure you see signs of fermentation before decreasing the temp. The time it takes may vary from one batch to the next; you can't just look at the clock and say, "Well it has been 24 hours since pitching, time to reduce the temp."

In my experience yeast will show signs of fermentation a lot sooner pitched at 20C than at 18C. Probably get a cleaner beer if started at 18C (instead of 20C,) but I am not sure I could tell the difference. YMMV.

Most yeast won't produce many new cells below 18C. 

Cheers,

Christina.

Edited July 20, 2021 by ChristinaS1

[iBooz2]

34 minutes ago, ChristinaS1 said:

Most yeast won't produce many new cells below 18C. 

Hold your horses Christina.  We are talking lager yeasts here.

Under normal fermentation (not including pressure ferments) most of those lager yeast strains we are talking about here would spend their entire lives below 18 C including their huge growth phase.

[ChristinaS1]

6 hours ago, iBooz2 said:

Hold your horses Christina.  We are talking lager yeasts here.

Under normal fermentation (not including pressure ferments) most of those lager yeast strains we are talking about here would spend their entire lives below 18 C including their huge growth phase.

You could be right. I always thought that the reason lagers call for much higher pitching vs ales is because metabolic processes are slower at lager fermentation temps, so higher pitching rates compensate for that. But I may be mistaken.

But lager yeast don't spend their entire lives below 18C: starters are fermented at room temps; I think that may be where I got the idea they did not reproduce well at cold temps....The D-rest is also done above 18C. 

Ah, here is an article that talks about it. https://braukaiser.com/wiki/index.php/Fermenting_Lagers

Cheers,

Christina.

Edited July 20, 2021 by ChristinaS1

[Tricky Micky]

12 hours ago, ChristinaS1 said:

@Mickep I agree with Kelsey's diagnosis of diacetyl and that it would be a good idea to leave it at D-rest temp for a week. AFAIK a two day D-rest is a minimum, not a maximum. 

If you are going to use one package of dry yeast and pitch warm, to get your cell count up, you have to be sure you see signs of fermentation before decreasing the temp. The time it takes may vary from one batch to the next; you can't just look at the clock and say, "Well it has been 24 hours since pitching, time to reduce the temp."

In my experience yeast will show signs of fermentation a lot sooner pitched at 20C than at 18C. Probably get a cleaner beer if started at 18C (instead of 20C,) but I am not sure I could tell the difference. YMMV.

Most yeast won't produce many new cells below 18C. 

Cheers,

Christina.

Many thanks @ChristinaS1 I'm pretty sure there was activity at the 24 hour mark after pitching before I reduced the temp but I will be more vigilant in future should I ever try that method again.

There seems to be a consensus here about a longer duration of a D-rest with a lager brew. I had been doing 3 days but as JM eluded to maybe I've just been lucky . I'll def take that on board in future. Thanks Christina for the feedback much appreciated.

[Tricky Micky]

4 hours ago, Pale Man said:

Been there and worked it out.  Enough has been said. Ferment as per lager yeast recommendation.  And ramp up to around 18 degrees when gravity is at 1.015ish. Just to clean up. For whatever ( 2 days ) bottle. Keg. Some lager yeast taste different need more conditioning. If you're like me it doesnt matter.  Gone in 60 seconds.

PM, with ya' brother. Up until now all my lagers have tasted beautiful. The only change in the process really had been the holding the FV at 18 degrees for around the first 24 hours - that's about all and got the dreaded Butterscotch flavour.  Apart from pitching a slightly greater amount of yeast  there's been no other change. It won't stop me making lagers though - luv 'em to bits.

[Pezzza]

7 hours ago, Mickep said:

PM, with ya' brother. Up until now all my lagers have tasted beautiful. The only change in the process really had been the holding the FV at 18 degrees for around the first 24 hours - that's about all and got the dreaded Butterscotch flavour.  Apart from pitching a slightly greater amount of yeast  there's been no other change. It won't stop me making lagers though - luv 'em to bits.

Hey there Mick

Sad to hear of your troubles mate but will be good to nail it

I dunno whether holding at 18 for 24 is that bad... I reckon you could brew a Lager/Helles w Dubbya at 18 for the whole ferment with DiA at 23... 

Have you tried brewing a Lager w Dubbya at 18 for the whole ferment with a patch warmer for DiA?

Was it a crappy batch of yeast?

Of course it is DiA

I am surprised as I have done all sorts of "bad" non-standard things to Dubbya Lager Brews and they have been just fine

I guess I subscribe to the general team consensus - more time for DiA Rest was probably warranted

And I say up to 21-22 and even 23 is fine for a DiA Rest... and hold it there for a bit... I think @ChristinaS1 and @Otto Von Blotto Kelsey might have mentioned more time for the DiA-Rest...

The other thing is what I learned from @Otto Von Blotto Kelsey - and Palmer - is the Yeast Cleanup - so don't Crash it - take it down 2 deg or say per day over whatever time it takes from 20 deg down to 3.... to give the yeast time to cleanup... the DiA rest shoulda nailed the butterscotch in the warmer phase... but I reckon that the slow cool down Yeast Clean-up phase is important for Lager/Pils yeast cleanup too...  just a thought

The ol' Dubbya is such a good yeast usually.... hey @MitchBastard Mitchie ; )  Any thoughts from you award winning brewer?  ; )

Good luck with it mate @Mickep Mick... I think over time it may dissipated anyway?

Edited July 21, 2021 by Graubart