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Green apple in Winter Warmer?

I brewed up my second batch of NB’s Winter Warmer recipe and I’m noticing the same hint of “green apple” with this batch as my first batch. I’ve been told that green apple flavor is the sign of a young beer but I’ve never had this issue with any other recipe/style of beer I’ve brewed. Is this hint of green apple common with, say, recipes that run heavy on marris otter or is it common to this particular style of beer if it’s fairly young?

I’d assume I had a brewing flaw, but this has only happened to me twice and it was with this same recipe.

Any thoughts?

P.S. I want to add that this batch was fermented at 66F and properly pitched with yeast starter. The beer is not undrinkable. In fact, I don’t think the average joe would even pick up on the hint of green apple so I doubt it’s an infection.

It’s just got me thinking so I’d be interested in any thoughts.

You may or may not be familiar with the following information but I will run it all down for you.
1.You had what seems like the correct temp for this strain as a lower temp is not advised.
2.You pitched from what I gathered to be a “correct” yeast starter (IE: w/o stir plate and shook at least initially real well to oxygenate boiled-cooled starter wort /Or injected with O2 1 recently dated wyeast pouch would call for a 2L starter for an OG: 1.069 and optimally shook every couple of hours etc… you would end up with 250 billions cells created from 80-100 b)

Great, at this point you fermented the beer to completion and in the process the yeast create ethanol along with a host of other “byproducts” of the ferment as listed: (NOTE- the levels included are for white labs WLP028 which is same/ similar to Wyeast 1728)
Flavor compounds:

Esters:

Ethyl Acetate: Fruity with solvent undertones when above the flavor threshold. Considered an off flavor in beer when in high concentrations. (Detection Limits=10-100mg/l, Typical Level in Beer=10-50mg/l, Flavor Threshold=30-50mg/l, Tested levels=26.45ppm basically equal to mg/l will shorthand the rest.)

Isoamyl Acetate: Can produce banana and pear-like flavors when above the flavor threshold.
(DT=1-10mg/l, TLIB=0.5-3.0mg/l, FT=1-2mg/l, TL=0.24ppm)
Fusel Alcohols:

n-Propanol: Because the typical level in beer is below the flavor threshold, this compound generally does not affect flavor.
(DT=1-1000mg/l, TLIB=3-16mg/l, FT=600-800mg/l, TL=35.09ppm)

Isoamyl Alcohol: Can produce wine-like or solvent-like flavors when over the flavor threshold.
(DT=10-100mg/l, TLIB=50, FT=70mg/l, TL=129.83ppm)
Others:

Diacetyl: Butter like aroma at moderate to high levels.
(DT=0.05-0.80mg/l, TLIB=0.01-0.60mg/l, FT=0.08mg/l, TL=32.33ppb=.003233mg/l)

2,3-Pentanedione: Produces honey like aroma at higher levels.
DT= Approx 0.1mg/l, TLIB= N/A, FT= N/A, TL=6.32ppb=.00632mg/l)

Acetaldehyde: Grassy odors, bruised apples, cidery notes. Immediate precursor to ethanol.
(DT=10mg/l Lagers and 25mg/l ales TLIB=N/A, FT= N/A, TL=9.88ppm)

1.0 mg/l = 1.001 ppm 1.0 mg/l = 1.0ppb/1000

When the ferment ends the yeast now also cleanup some of these compounds so levels after week 1-2 will be greatly reduced if left in contact with a good portion of the yeast for a period of time usually 1-4 weeks depending on many factors sometimes months as is the case with lagers such as bocks, Marzen etc…as you then add other compounds such as SO2 depending on lager yeast strain.

You have hints of what is typically symptomatic of Acetaldehyde which typically “ages” or “conditions” out as a function as described above. This is one large reason in which you should not rush a ferment into the serving vessel until flavor trials indicate the beer is ready to consume and at it prime. (IE: no young characters.)

Ok, so that is the full story. I will though go on to mention one other thing that needs mention regarding fusel or higher alcohols usually the rate of fusels depends on temp, pitch count, oxygen or the lack of the following three but here is one other thing----- I made a good number of Sam Smiths Winter Warmer clones for a number of years that came out fine although a slight too much percentage of fusels in some of the ferments and the one thing I finally understood is that at any OG/ Recipe over 1.065 I typically now use a percentage of Sugar, Invert, Candi sugars etc… the reason why is you have far too many amino acids and FAN so the yeast are basically forced to create the higher alcohols. Whereas by using the sugar in percentage you cut the amino acids and FAN down so they are not forced into hyper drive. I’am obviously glossing over this quite a bit, but it was an AHHA moment when I read this about British and Belgian brewers using this practice to create BIG OG beers but with low fusels and in the end you get a more rounded brew. I tend to ramble sometimes. But I hope this was just good follow up info in the same vein of topics.

Acetaldehyde boils at about 68 or 70 F. You might just want to warm up the beer for a few days while it is still in the fermenter, or you could pressurize and off-gas if it’s kegged. If bottled, you might be stuck with it.

Thanks guys. It’s currently kegged and I doubt very much that the beer got above 66F throughout the fermentation, racking process (my basement is cold). I think I’ll take the keg upstairs and let it warm up and try to off-gas. I think it’s te only solution at this point.

Thanks again.

I just recently fought and lost a battle with an acetaldehyde bomb in a pilsner I brewed. I tried warming up. I tried repitching. But in the end, the solution was clear. I dumped it. If, as you mention, your beer is drinkable, I would dispose of it by drinking and enjoying it. But in my case, the flaw was just too prevalent, and the beer was not salvageable. YMMV.

I know exactly what caused it in my batch. I got antsy. I had company coming in town and so I rushed my fermentation. I racked the beer too soon and learned my lesson.

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