[quote=“Pietro”][quote=“Beersk”][quote=“Pietro”]Hope this isn’t too off-topic on this thread, but we stressed 34/70 a bit (didn’t rehydrate, pitched 3 or maybe 4 sachets into a 14 gallon bo pils) and it threw off a bunch of red apple, which was really not good. Not green apple/acetaldehyde…but red…like apple juice- Ethyl hexanoate per my research.
However, I was wondering if I brewed a 5G ale/hybrid batch with this yeast, say a cal common, fermented at around 60 degrees, primarily to start growing up a big slug to brew a baltic on the 14 gallon system, would it throw off those ugly esters at that temp?[/quote]
You know, I think I’ve gotten this flavor before but wasn’t sure what to think of it. Not sure if it comes from fermenting too warm or underpitching or what.[/quote]
We scratched our heads like crazy because we thought it was acetaldehyde. It definitely was more ‘apple juice’ than ‘sliced green apple’ so we settled on ethyl hexanoate. My understanding is that it comes from stressed yeast. I think this is what we did because we didn’t rehydrate, which I’ve heard kills about half of the viable cells (I believe it was 3 sachets). No way it was ferment temp in this case, we pitched and held the temp at 50* or so for the first week and half, then raised up into the 60’s for a d-rest for another few weeks.
Next time I’m repitching from slurry, 2nd-gen minimum for any lager.[/quote]
Interesting, so you think this was stressed yeast, eh? I usually rehydrate my yeast. But I’m bad about getting the rehydrated yeast down to pitching temp before pitching it into cold wort.
Last week I bottled a helles bock made with S-189 that turned out great.[/quote]
Been meaning to try that yeast. Wish it were more widely available.[/quote]
The manufacturer is supposed to be making this available in home brew sizes some time soon.
In the meantime Atlantic brew supply repackages from the large bricks and has a USPS shipping option that wouldn’t cost a lot to get 2 or 3 packs.
Last week I bottled a helles bock made with S-189 that turned out great.[/quote]
Been meaning to try that yeast. Wish it were more widely available.[/quote]
The manufacturer is supposed to be making this available in home brew sizes some time soon.
In the meantime Atlantic brew supply repackages from the large bricks and has a USPS shipping option that wouldn’t cost a lot to get 2 or 3 packs.[/quote]
I got on their website to check and the USPS charge for 3 packs was $2.52.
[quote=“Beersk”][quote=“Pietro”][quote=“Pietro”]Hope this isn’t too off-topic on this thread, but we stressed 34/70 a bit (didn’t rehydrate, pitched 3 or maybe 4 sachets into a 14 gallon bo pils) and it threw off a bunch of red apple, which was really not good. Not green apple/acetaldehyde…but red…like apple juice- Ethyl hexanoate per my research.
However, I was wondering if I brewed a 5G ale/hybrid batch with this yeast, say a cal common, fermented at around 60 degrees, primarily to start growing up a big slug to brew a baltic on the 14 gallon system, would it throw off those ugly esters at that temp?[/quote]
We scratched our heads like crazy because we thought it was acetaldehyde. It definitely was more ‘apple juice’ than ‘sliced green apple’ so we settled on ethyl hexanoate. My understanding is that it comes from stressed yeast. I think this is what we did because we didn’t rehydrate, which I’ve heard kills about half of the viable cells (I believe it was 3 sachets). No way it was ferment temp in this case, we pitched and held the temp at 50* or so for the first week and half, then raised up into the 60’s for a d-rest for another few weeks.
Next time I’m repitching from slurry, 2nd-gen minimum for any lager.[/quote]
Interesting, so you think this was stressed yeast, eh? I usually rehydrate my yeast. But I’m bad about getting the rehydrated yeast down to pitching temp before pitching it into cold wort.[/quote]
I have this same flavor and aroma in my vienna lager. Used 34/70, pitched at 48-50, 8 packs not rehydrated in 11 gallons very wel aerated 1.052 wort. No signs of fermentation after 24 hours so let the temp rise one carboy showed krausen at 52 after 72 hours the other at 54 after about 80 hours. I kept at 54 for 4 days then let it rise to 68-70 for a few weeks then lagered 3 weeks at 33 degrees. 1.014 at room temp before racking to keg.
Haven’t checked the second keg yet to see if it has the same issue. Really bummed because I reused the yeast cakes for 11 gallons of pilsner. The cake was very thin and concerned me…should have followed my gut and not used it.
Interesting - seems like this is the alcohol ester of caproic/hexanoic acid. I’m assuming this must be an autolysis product due to the dead yeast from not rehydrating the yeast prior to pitch? Makes sense that the surviving yeast cells would esterize this acid at the start of fermentation.
thats interesting, so maybe this yeast has a thinner cell wall that can rupture more quickly/easily? Most of today’s ale strains are complete animals and even when dormant or dead, do not rupture, at least in my experience.
Could be… I’m just making a complete guess here, but I’m not sure where else you would get the caproic acid. I’m reading that you can get it from the skins of some fruits and seeds, but if it came from malt then I would think it would be a lot more common. It’s strange that the two of you would have a similar experience with the same yeast, unless it is indeed from the yeast itself.
34/70 direct pitched into a pils/wheat base, tropical hops at flameout, brett pitched in secondary, heavy dry hop… hmm…
@Pietro, have you seen this article? Just stumbled across it this morning. The author shows the metabolic pathways for various fermentation products. I don’t know much about organic chemistry, but from some google searches, it appears that hexanoic acid is an intermediate product from certain amino acids, which can be converted into higher alcohols and then into esters. Possibly coming from dead yeast or from trub carried over from the BK?
Took gravity reading on my pils and it was clear, tasted great, no sign of apple aroma or taste, 1.012. Racked to kegs for lagering. The yeast cake was much healthier looking than when I racked off the vienna. If it was autolysis from stressed yeast I suppose they could have released all the apple-y badness ethyl hexanoate or whatever into the vienna then when fermentation started in the pils the healthy yeast cleaned everything up??
Danny, have you ever tried brewing a blending beer? The Vienna with the apple flavor might be a lousy lager, but maybe you could make a hoppy red ale to blend with it to make a nice Amber. Or an extra hoppy IPA, might be great blended with an estery Vienna. I think this is an area where homebrewers really need to explore, as you can make some great beers by blending! Not much to lose…
[quote=“dannyboy58”]I blended it with the fluids in my septic field today.
Needed the kegs to get some more beers on tap.[/quote]
Really sucks to have to dump beer like that. Sorry to hear (read) that. I tried my Munich helles with WLP838 yesterday, still hazy but delicious! I really love that style when done well. Pretty much the only ones I’ve had that have been really really good are ones that a friend and I have both homebrewed. Commercial helles bier don’t really cut it, unless they’re German and on tap. And even those lose a lot of their fresh malt character by the time we get them.
[quote=“porkchop”]@Pietro, have you seen this article? Just stumbled across it this morning. The author shows the metabolic pathways for various fermentation products. I don’t know much about organic chemistry, but from some google searches, it appears that hexanoic acid is an intermediate product from certain amino acids, which can be converted into higher alcohols and then into esters. Possibly coming from dead yeast or from trub carried over from the BK?
Wow, I didn’t even think of trub causing it. We have an inline plate chiller so a good amount of cold break is likely in the fermentor.
I am still hoping it was an underpitch by not rehydrating (or aerating). The pitch of 34/70 I grew up likely also has a good bit of trub/cold break mixed in, so I’m really hoping that isn’t the cause!
[quote=“Pietro”][quote=“porkchop”]@Pietro, have you seen this article? Just stumbled across it this morning. The author shows the metabolic pathways for various fermentation products. I don’t know much about organic chemistry, but from some google searches, it appears that hexanoic acid is an intermediate product from certain amino acids, which can be converted into higher alcohols and then into esters. Possibly coming from dead yeast or from trub carried over from the BK?
Wow, I didn’t even think of trub causing it. We have an inline plate chiller so a good amount of cold break is likely in the fermentor.
I am still hoping it was an underpitch by not rehydrating (or aerating). The pitch of 34/70 I grew up likely also has a good bit of trub/cold break mixed in, so I’m really hoping that isn’t the cause![/quote]
Based on my experience of repitching the same yeast to my pils it wouldn’t appear that trub is the culprit. I just racked the vienna off to kegs and pumped the pils right onto the cakes. So it had 2 batches worth of trub.
I use a plate chiller as well and really don’t spend much time whirlpooling unless I’m doing a FO/whirlpool hops addition.
Drinking the pilsner that got 2nd gen 34/70 after it threw ethyl hexanoate(?) in the vienna. The pils is a nice young pils. Lagered not quite 2 weeks yet. No hint of the apple flavor or aroma.
