w34/70 fruity?

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fletcher

bibo ergo sum
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hey guys.

i've not made many beers with this yeast, but decided to try lagers a few months back and have given one in particular a good 8 weeks in the bottle to hopefully allow it time to condition. a few points:

1. it's a simple beer with pilsner malt, and wakatu hops to 23ibu
2. pitched 2 x packs at 16c, while it was on its way to 11c
3. fermented at 11c and got close to FG in about 5 days
4. bumped up to 20c for a d-rest (here is where i think the issue is)
5. cold crashed and bottled 4-5 days later
6. it's been sitting in the bottle "lagering" at 3c for about 3ish months.

it has a very fruity yeasty character for my tastes. not fruity as in hop fruity (even though wakatu is a hallertau variant, i wouldn't call it fruity) but as a very uneducated guess, it is as though the d-rest has caused the yeast to give off a distinct fruity ester.

have any others had this? can anyone shine any light on it? i'd have thought that the ferment at 11c for 5 days would have meant it had no/minimal ester.
 
I've done a few pilsners using a similar fermentation schedule, albeit with Saaz hops and Wy2001 yeast, 10C ferment for 5-6 days, 18C D-rest til day 14, and CC'd for 2 weeks before bottling/kegging. These were consumed well before 3 months as well. No esters whatsoever. Have yet to try this new schedule of mine with W34/70.

I had brewed some lagers with Hallertau a couple of years back with W34/70, using my old fermentation schedule. These were raised to about 16C after the bulk of fermentation had been completed (fermented at 11.5C), cold crashed in the FV for 5 weeks and these didn't present with any fruity estery type flavours either. Only real difference here is the temp of the D-rest and the length of time sitting at 0 in the FV before they were bottled.

All these batches were pitched with large yeast starters, that be another point of difference.
 
Hey Fletcher. I use that yeast and I don't get that flavour you talk of. Can you explain more why you think the D rest would do that? 11-20 is a fair jump for a D rest, you really only need a 15-16 degrees rest when the beer hits approx 1.020. Having said that after 5-6 days of a ferment and close to FG you should not have a problem. I have not used Wakatu hops so can't comment there.
 
Rocker1986 said:
I've done a few pilsners using a similar fermentation schedule, albeit with Saaz hops and Wy2001 yeast, 10C ferment for 5-6 days, 18C D-rest til day 14, and CC'd for 2 weeks before bottling/kegging. These were consumed well before 3 months as well. No esters whatsoever. Have yet to try this new schedule of mine with W34/70.

I had brewed some lagers with Hallertau a couple of years back with W34/70, using my old fermentation schedule. These were raised to about 16C after the bulk of fermentation had been completed (fermented at 11.5C), cold crashed in the FV for 5 weeks and these didn't present with any fruity estery type flavours either. Only real difference here is the temp of the D-rest and the length of time sitting at 0 in the FV before they were bottled.

All these batches were pitched with large yeast starters, that be another point of difference.
yeah i think the difference is my d-rest temp. i have no idea why i pushed it so high. can i ask with your hallertau brews, were they quite clean? i was after a super clean bland lager - not too hoppy like a pilsner.

razz said:
Hey Fletcher. I use that yeast and I don't get that flavour you talk of. Can you explain more why you think the D rest would do that? 11-20 is a fair jump for a D rest, you really only need a 15-16 degrees rest when the beer hits approx 1.020. Having said that after 5-6 days of a ferment and close to FG you should not have a problem. I have not used Wakatu hops so can't comment there.
yeah i think the d-rest might have been the reason but have no idea really why, i'm just guessing which is why i asked on here. i read one other comment on ahb with a member who actually said once he d-rested too high it got fruity and i wondered if that's the issue i have. i would have thought after the bulk of ferment that there wouldn't be any other flavour contributors, but i wasn't sure about esters. the beer is completely clean flavour-wise, but has an over-riding ester which i just don't like with lagers. way too fruity :(

were your lagers really squeeky clean with it? no esters or yeast flavours to speak of?
 
fletcher said:
yeah i think the difference is my d-rest temp. i have no idea why i pushed it so high. can i ask with your hallertau brews, were they quite clean? i was after a super clean bland lager - not too hoppy like a pilsner.
They were clean yeah. I wouldn't say bland, but definitely clean. I based my recipe on the Munich Helles style, although I hopped it up a little more to suit my taste but not as far as a pilsner. In any case, no yeasty flavours or esters to be found. I really enjoyed those beers... will see how much Hallertau I have left, might have to do another one after my next pilsner.
 
What was you're OG, FG & what was you'e reading when you raised for the D rest
 
manticle said:
What fruit?
pear. very estery, as soon as the bottle opens you can smell it. not in a pleasant way as it stands out way too much and certainly wasn't what i was after. i'd never thought to actually check what kind of fruit til you just asked :)

edit: typos

rude said:
What was you're OG, FG & what was you'e reading when you raised for the D rest
OG - 1.045
FG - 1.005
i d-rested when it got to 1.007 as it fermented so fast. took only 5 days at 11C to reach 1.007 and i'd expected a much longer initial ferment so was shocked as that was my first reading post-pitch. was meant to ramp it to d-rest once it had reached about 50% attenuation.
 
How long did it take to get from 16C to 11C after pitching? Yeasts can throw esters in the growth phase when pitched too warm.

I haven't had that direct experience with 34/70 but Mangrove Jack's BoPils yeast definitely needs to be pitched at fermentation temp.
 
Pear usually means ethyl acetate, which tastes like ripe apples or pears at lower levels. Under pitching, under oxygenating, higher fermentation temp in the early stages and possibly carry over of fatty lipids from the kettle if you transferred too much cold break are the usual causes. The D rest temp is unlikely to be the issue as esters and their precursors are mainly produced in the growth phase.

I'd suspect it's a mixture of under oxygenation / aeration (only because you don't seem to mention it), possibly a slight under pitch (depending on who you read viable cells per gram of dried yeast is somewhere between 10bn and 20bn cells per gram) and pitching at 16C.

The good news is that it generally dissipates over time, the bad news is that it can take a fair few months or longer depending on intensity of flavour.
 
Can't imagine d rest at 1007 would cause it.
My guess is the warmer pitch temp. Was the yeast fresh and well cared for?

Also oxygenation as mentioned above.
 
I'm just wondering if it could be acetaldehyde which most people perceive as green apple but you may pick it up differently.

I don't think pitching temp would be the problem. I know plenty of people ferment higher with that yeast and still report clean lager characteristics.

As said above I generally only have sulphur issues with this yeast although I don't use it regularly.
 
I doubt you'd mistake acetaldehyde (fresh green apples) for ethyl acetate (ripe pear/fruit drops in low concentrations), but it is possible as we all seem to perceive flavour differently and have widely differing taste thresholds. At the past vicbrew one judge described my way too young Pilsner as laden with acetaldehyde, whilst another suggested it was esters typical of a too warm ferment. I just tasted it as crisp but very young and in need of a few more weeks lagering.
 
One thing I've never got my head around is bottle conditioning lagers. By the time I bottle a lager I've dropped out as much in suspension as possible, so the yeast quantity in the bottle is minimal. It then goes through secondary fermentation and having such a low cell count, will surely stress the remaining yeast. So you can either -

1. Condition/ferment at 3°C where the yeast will be stressed further. Likely diacetyl.
2. Leave at 12°C while conditioning
3. Leave at ambient. Less stress on the yeast but will produce more esters and probably fruitiness as a result

I've tried 1 and 3 with poor results. Diacetyl when left cool, undesirable esters when left warm. Perhaps bottling is the main problem here? I've only ever had success when kegging lagers. I've never tried to bottle a full brew, only bottle what's left over after kegging.
 
Can't say I've had that issue with lagers that I've bottled, even after they've been lagering for 5 or 6 weeks prior to being bottled. :unsure:
 
first of all. thank you all so much for your help and ideas for causes. i'm sure one of the things you've mentioned, maybe more, are to blame and i really really appreciate your help.:)


Barge said:
How long did it take to get from 16C to 11C after pitching? Yeasts can throw esters in the growth phase when pitched too warm.

I haven't had that direct experience with 34/70 but Mangrove Jack's BoPils yeast definitely needs to be pitched at fermentation temp.
i can't recall exactly and sadly nor did i write it down, but from memory, about 3-4 hours.

Blind Dog said:
Pear usually means ethyl acetate, which tastes like ripe apples or pears at lower levels. Under pitching, under oxygenating, higher fermentation temp in the early stages and possibly carry over of fatty lipids from the kettle if you transferred too much cold break are the usual causes. The D rest temp is unlikely to be the issue as esters and their precursors are mainly produced in the growth phase.

I'd suspect it's a mixture of under oxygenation / aeration (only because you don't seem to mention it), possibly a slight under pitch (depending on who you read viable cells per gram of dried yeast is somewhere between 10bn and 20bn cells per gram) and pitching at 16C.

The good news is that it generally dissipates over time, the bad news is that it can take a fair few months or longer depending on intensity of flavour.
all i did for oxygenation was splash the wort and rock the fermenter back and forth as it was chilled going from the grainfather. usually i splash it as much as possible and from the chiller, it pours from a height, splashing into my fermenter which has been great for ales, but perhaps not enough for lagers?

i pitched 2 packs of fresh yeast. both packs hydrated in water and then poured into fermenter at 16c - which from memory was there for about 3-4 hours on the way down to 11c.

the smell is pretty intense. quite a strong ester which to me is off-putting but fingers crossed this dissipates.

manticle said:
Can't imagine d rest at 1007 would cause it.
My guess is the warmer pitch temp. Was the yeast fresh and well cared for?

Also oxygenation as mentioned above.
yeast was fresh and cared for, yes.

Parks said:
I'm just wondering if it could be acetaldehyde which most people perceive as green apple but you may pick it up differently.

I don't think pitching temp would be the problem. I know plenty of people ferment higher with that yeast and still report clean lager characteristics.

As said above I generally only have sulphur issues with this yeast although I don't use it regularly.
definitely wasn't the green apple flavour i pick up from young beers. i'm no judge but i really try and pinpoint my smells and am getting much better at picking them. it's definitely pear to my senses. i'd be completely happy though if it was just young and improved soon :)

TheWiggman said:
One thing I've never got my head around is bottle conditioning lagers. By the time I bottle a lager I've dropped out as much in suspension as possible, so the yeast quantity in the bottle is minimal. It then goes through secondary fermentation and having such a low cell count, will surely stress the remaining yeast. So you can either -

1. Condition/ferment at 3°C where the yeast will be stressed further. Likely diacetyl.
2. Leave at 12°C while conditioning
3. Leave at ambient. Less stress on the yeast but will produce more esters and probably fruitiness as a result

I've tried 1 and 3 with poor results. Diacetyl when left cool, undesirable esters when left warm. Perhaps bottling is the main problem here? I've only ever had success when kegging lagers. I've never tried to bottle a full brew, only bottle what's left over after kegging.
i will say that they bottle conditioned a bit warm and i hadn't even thought of that. it was the middle of sydney summer and my apartment can be a sweat box apart from the kegerator and ferment fridge. so they could have been as hot as 25-27C.

------------------------
eek. looks like it could be a combo of or one of:

- 16c pitch temp and the 3-4ish hours to get to 11c
- under-oxygenation
- bottle conditioning temp

good thing is i have another lager with the same yeast and similar temps for pitching, ferment and d-rest, in the keg. haven't sampled it yet, but if it's better in the keg, it could rule out the bottle conditioning factor. i'll taste it tomorrow and see how it goes - it's been kegged at 2-3C for 6 weeks.

thanks again everyone. you're all amazing. really appreciate it.
 
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