First Lager Balls Up Diacetyl After Rest

[Charst]

Thought id brew a lager to appease my mega swill mates and serve at my birthday on the 26th. munich helles from brewing classic styles.
OG was 1050 (should be 1048) finished 1012. bittering addition only.

After 10 days ferment it was Diacetyl city so i raised it to 18 to do a D-rest and after about 4-5 days it certainly had dropped off but at that point and tasting temp i wasn't sure if what was left with was a malt/low attenuation sweetness or a honey buttery sweetness of diacetyl. (probably both)

So stupidly i hit the go button and have been layering for two weeks at .3.
Taste tonight and i still get the taste, its diacetyl, I'm sure (I've drunk grand ridge)

so what can I do?

Im thinking of getting a starter going in a 500ml flask. get it to high krausen on the stir plate.
Raise the beer to 18 and dump the active starter in to clean up the beer.

Other option i dry hopping with amarillo and be done,

thoughts from experienced lager brewers?

 

[dougsbrew]

do you have enough time to make an ale, hard to please a megaswiller..

 

[Dazza88]

I am not an expert but just read if you add actively fermenting wort tothe main brew at say 18 it may reduce it. I think diacetyl is reduced by yeast not so much by lagering.

Out of interest what temp did you start ferment at? What yeast? Munich?

 

[Charst]

no time to knock out an ale, ferment with Wyyeast 2308 at 12 degrees.yes i know lagering doesn't clear diacetyl, i just made a dumb decision to lager earlier than i should have

 

[manticle]

Adding yeast and raising temp, if the diacetyl isn't due to other causes (eg infecyion), is your best bet.

 

[Charst]

Nothing Looks/Tastes like infection so I'm firing the starter up now. Cheers

 

[seemax]

Brew a wit ... 4 days at 22C with 3068 ... straight to keg :unsure:

 

[Charst]

Brew a wit ... 4 days at 22C with 3068 ... straight to keg :unsure:

yeah original post did state i was brewing a lager for my megaswilling mates. I wit aint going to cut the mustard

 

[Maxt]

Unless you have filtered there will be enough yeast to get the job done in the keg/fermentor. I have done this (too often) to get rid of diacteyl in lagers. I pull the keg out of the fridge, sit it on the shed floor, purge all gas, give it a shake. Leave purge 30 mins later . Every morning purge then quick roll/shake. Diacetyl will be gone in a week. Adding more yesat increases risk of infection and oxidisation.

 

[Dazza88]

nice, thats good too know Maxt. I watch this thread as i prepare to do my first lager run this winter - gonna run lager yeasts at 9~10C for ferment.

Is diacetyl caused by higher temps at start of ferment?

The only 2308 lager i ever tasted was butterscotch city. Turned me off using it. I have bought hella bock, it mentions a diacetyl rest is recommended.

 

[donburke]

nice, thats good too know Maxt. I watch this thread as i prepare to do my first lager run this winter - gonna run lager yeasts at 9~10C for ferment.

Is diacetyl caused by higher temps at start of ferment?

The only 2308 lager i ever tasted was butterscotch city. Turned me off using it. I have bought hella bock, it mentions a diacetyl rest is recommended.

pitchimng warm then cooling tends to stress yeast, which can produce excessive diacetyl

so too can underpitching

pitch big and pitch at your ferment temp and you should be able to avoid or at very least minimise it

i recently pitched onto a whole yeastcake at 3 or 4 degrees and fermented it at 7.5 degrees and dare i say its a very clean lager, all done within 2 weeks

 

[MHB]

I have been reading brewers comments on making Lager with increasing alarm; It appears that some very fundamental problems are coming up again and again.
Basically to make Lager successfully you need three things: -
Lots of healthy yeast
Good temperature control
Patience
Yeast makes Diacetyl then eats it as part of the fermentation process, arguably if you still have significant amounts of Diacetyl you havent finished primary fermentation and are not ready to chill the beer to Lagering temperatures. I dont think most home brewers get their heads around the size of pitches (or the quality of the yeast) used in commercial brewing, or the effect that this has on their brewing.
There was a discussion recently about the performance of WY 2000 Budvar yeast; in a quote by the head brewer he said they use 5 L of heavy slurry / 100L of wort, call it 1L/25L of wort.
Looking at the Wyeast website they estimate heavy slurry as having 1.2 Billion cells/mL, so 1 L of heavy is 1000 x 1.2x10^9 or 1.2x10^12, a fresh smack pack claims 100x10^9 so the equivalent of 12 fresh Wyeast packs.
Im going to leave it to others to work out how big a starter Mr Malty thinks you need but you arent getting anywhere near close in a 2 L Erlenmeyer flask on a magnetic stirrer.
Given the amount and health of commercial pitches, Kunze has several profiles for Lager fermentation here is the one that most closely resembles what most home brewers can achieve (these are designed for CCVs), you can see from the black arrows where yeast is removed, of particular note is the lighter solid line showing Diacetyl, it is the measure of the Diacetyl content that tells the brewer its ok to crash chill.
I strongly suspect that it is the yeast collected between the 7-10 days that is used for repitching.
View attachment 54336
Left hand scale %=^oP dashed line (SG = (^oP *4)/1000 + 1) and ^oC is temperature, dark solid line.

Please note that there is no ramping the temperature up at the end, it is neither necessary nor desirable if the yeast can do the job without it.
Realistically few home brewers will ever achieve commercial quality yeast pitches. To make lager successfully you need the biggest healthiest yeast pitch you can manage and then you need to wait until fermentation is complete.
What is of major concern is not just the amount of yeast but the health of that yeast. Reading a lot of the comments here on making starters and propagating yeast I believe there is very good reason to be seriously concerned about the health of a lot of the yeast being used.

Yes I find it rather daunting and dont really have an answer, on a personal level I hope to be able to propagate much larger healthier pitches soon, but I do think its time for us to revisit yeast propagation in a more rational and constructive way.
Mark

 

[Charst]

Thanks to all I think i should have posted a few more stats in the Original post.

pitched approx 350 billion cells of Wyeast 2308 (calculated with yeast calc.com and stepped up on stir plate 3 times between 2 and 3 litre erylen meyer flasks
to archive total, using DME and Wyeast nutrient) into 20 litres of Munich Helles in willow cube at 11 degrees (temp controlled fridge). Wort only shaken to aerate but shaken for about 10 minutes,
partially unscrewing cap and sucking fresh air in every 2 minutes or so.

Mark you make a point about the quality of the yeast but this is the best method i believe i can achieve of pitching healthy yeast in.
Otherwise should i slightly over pitch in future to accommodate for possible poor yeast health?
that sounds like my aiming left to compensate for my slice in golf. A big no no.

OG 1051
IBU 18 Spalt bittering only.


Fermented at 11 degrees for 8 days. taste. Diacetyl,
leave at 11 for 4 days, 12 total, taste, Diacetyl.
Raise to 17 degrees, leave for 4 Days, Way less still a bit there.
Leave for 2 more days, no change.

*have a massive brain fade and hit the crash chill button.

Lagered for 2 weeks so far and thought i do a taste. Subtle honey butterscothy still there..

I don't currently have any kegging gear (i will by my birthday ) to purge and shake as suggested. Im hesitant to shake any fermented wort at all.

Last night built 1 litre starter of coopers dry ale yeast on stir plate and intent on pitching it into the cube while still active at 18 degrees
(about 19 litres left after all the samples)

Intend of a gently stirring into the beer no shaking. leave for 4 days and taste.

Thoughts?

 

[Dazza88]

In reference to MHB's post, and dons . .

maybe it would work to build a 2L starter, brew 10L batch, collect a lot of the slurry, do a 21 L batch?

 

[MHB]

In reference to MHB's post, and dons . .

maybe it would work to build a 2L starter, brew 10L batch, collect a lot of the slurry, do a 21 L batch?

That may in fact be the only way.
A big part of the problem as I see it is I dont believe people are getting the yeast counts they think they are, at a bare minimum we need constant aeration to achieve anything like the number of doublings that the literature suggests are possible, those are maximums, people write as if they are what they are getting.
As soon as yeast runs out of O2 it stops reproducing, switching it back and forward between aerobic and anaerobic conditions (i.e. intermittent shaking) isnt going to be doing its health any good at all and I believe will do serious harm. Allowing the yeast to progress through its full life cycle at least allows it to be fully prepared for the next generation.
In a well aerated wort (lacking constant aeration) you should see a 6-8 fold increase in the population in each fermentation cycle, given a wort that supplies all the nutrients the yeast needs and low stray bug counts I am coming to the conclusion that fermenting out the culture (and acid washing at need) before repitching may be the best approach.
If we are using Wyeast, I would discount the 100 Billion starting number; there are plenty of references on how much.
Im far from confidant that I have all the answers but the number of threads about unsatisfactory or incomplete fermentations points to a large number of brewers having problems with their yeast pitch, health or both and makes this a good time to ask some serious questions.
Mark

 

[donburke]

In reference to MHB's post, and dons . .

maybe it would work to build a 2L starter, brew 10L batch, collect a lot of the slurry, do a 21 L batch?

yes, and then when the 21 litres is done, pitch 40 litres onto that yeast cake

 

[Maxt]

pitchimng warm then cooling tends to stress yeast, which can produce excessive diacetyl

so too can underpitching

pitch big and pitch at your ferment temp and you should be able to avoid or at very least minimise it

i recently pitched onto a whole yeastcake at 3 or 4 degrees and fermented it at 7.5 degrees and dare i say its a very clean lager, all done within 2 weeks

From Wyeast web site:
"For lagers, we recommend inoculating the wort at warm temperatures (68-70F/ 20-21C), waiting for signs of fermentation, and then adjusting to the desired temperature."

The other things to consider is when you do your D rest. If you wait too long the yeast are spent and can't clean it all up. I try and aim for 1.020 (depending on O.G) to do my rests.

I have also moved from 2-3.5L starters, and as soon as I can get a bigger container I will be going with 4.5L for lagers.

 

[Renzo]

For lagers now I only use S-189. Used to use wyeast etc and never had the same success rate I've had with 189. Pitch 2 packs @10-12c, wait 10-12 days then lager for another 10 then filter >keg (i.e.) the Ross method) Never had any diacetyl, sulphur and brew a crisp clean, bready, doughy helles everytime.

 

[Dazza88]

I have 2278 and 2487 for a lager run. I have 2 x 2l erlynmeyers so i thinkk i wll do this.

Make 1.4l starters of each. Still deciding on temps for starter , have stir plate. Have a small wine fridge to maintain temps 8 to 18.

Ferment main batches at 8 to start then raise to 10.

First batch - 20l of boh pils, split into two, brew a yeast into each 10l batch.

Then use the cakes for bigger batches.

2278 boh and german pils. 20l.
2487, helles, doppelbock etc. Mabye 15l for doppels higher og.


Hopefully keezer will b rdpaired for lagering. Otherwise just do one yeast at a time.

Any improvements suggested?

Dont have a 40l fermenter don.

Sorry to hijack charst. Is the butterscotch improving?

 

[Goose]

This sounds a little like my last experience debated here:

http://www.aussiehomebrewer.com/forum/inde...showtopic=64082

One of the conclusions I drew from this is that oxygen during transfer/racking can set off an aerobic finish to what might be an almost complete fermentation. In my case I could detect no diacetyl throughout fermentation right to when I thought it was complete. Because of that I never did any diacetyl rest because I'd incorrecly presumed that the yeast had done its job. It only showed up gradually after I'd racked and commenced lagering. To correct it, I had to raise the temperature to 19 deg C for a week and even then I could still detect it, but it was much improved but to me its still not right.

I put down the diacetyl formation to O2 during transfer to secondary that kicked off maybe a tad of fermentation that was incomplete, though the FG did not suggest such. My starter was a healthy 4 litre using a stir plate grown from a single Wyeast smack pack, this is pretty much in line with the Mr Malty calculator for a 12 gallon batch. I accept that it is possible, as suggested in this thread that the viability of the yeast may not have been up to scratch because I left the fermnet 3 weeks before racking, and I repeat it tasted simply awesome immediately prior to racking, so much so I thought i was on a winner. You can imagine my disappointment after sampling it a week later.

For my most current batch I had to make do with what I had, which was two Saflager dry packs, which I hydrated before pitching to 10 gallons of 12 deg C wort. Mr Malty would prefer me to use 4 packs, but it nonetheless merrily fermented out in two weeks. I'm currently letting the temperature drift up to 19 deg C for a few days for a rest after which I will crash cool to 2 or 3 deg C and then rack. My racking this time will be 100% closed system into CO2 purged kegs to minimise air contact.