Apple Juice?

[AlexKay]

Summary: I tried to brew an American Pale Ale, and it tastes like apple juice.

It's a 2.5-gallon batch:
5 lbs. Pale Malt (Mecca Grde)
0.5 lb. Vienna Rye (Mecca Grade)
0.25 lb. Light Crystal (Simpson's)
8 g Magnum @ 60 min.
10 g Ahtanum @ 20 min.
10 g Ahtanum @ 0 min.
11 g Safale US-05
BIAB, Mashed at 153
Fermented at 68 F for two weeks

The OG was 1.062 and the FG 1.008. The beer tastes nice and grainy, up until the point the apple juice hits you. Strong, sweet, apple-y flavor.

The internet says acetaldehyde is "green apple" -- what does it mean by "green"? I just taste apple, and it's sweet rather than dry or sour. And if it's acetaldehyde, how did I get it, and what do I do to avoid it again? There should be plenty of healthy yeast, and if two weeks isn't enough for clean-up, how do I know what is?

I haven't used Ahtanum before, but the descriptions all say "citrus." And I didn't think US-05 made fruity esters.

Any thoughts and ideas on how to avoid this in the future would be very much appreciated. It's ruined as beer, and I'd give it to my kid except it's 7% ABV, so I think it's for the drain.

 

[Shawnstve]

Sounds decent, I mean it’s not what your going for I get that, but why not drink it? I’m rather new to brewing so I cannot comment on how to fix that, but That sounds like an easy drinker at 7%? Unless it just tasted similar to apple juice but bad tasting. Haha!

 

[RM-MN]

Acetaldehyde is a normal byproduct of fermentation and given the right conditions the yeast will metabolize it. It is usually caused (I think) by keeping the beer too cool during the tail end of fermentaion. The usual way to eliminate it is to keep the beer cool for the first few days (5 to 7 days) to control the esters and fusel alcohol that the yeast produce when allowed to ferment too warm, then let the beer warm to encourage the yeast to clean up the byproducts of fermentation like the acetaldehyde.

Now with all that, each of us have differing senses and what you taste as apple I may taste as mango. There may be nothing wrong with your beer, it just may not be to your liking. If possible let someone else taste the beer and get their impressions. It may be that you simply do not like the aroma/flavor of Ahtanum hops in which case you simply quit using them.

 

[RPh_Guy]

The internet says acetaldehyde is "green apple" -- what does it mean by "green"?

Kind of sour-ish, like Granny Smith, or unripe apples of other varietals.

And if it's acetaldehyde, how did I get it, and what do I do to avoid it again?

I recommend everything that promotes good yeast health:

• Proper pitch rate (looks like you over-pitched)
• Proper aeration/oxygenation
• Yeast nutrients containing zinc, added direct to fermenter e.g. Wyeast nutrient
• Controlling the actual beer temperature during fermentation (not just ambient), personally I would aim for around 65-66°F with US-05

 

[TenaCJed]

Kind of sour-ish, like Granny Smith, or unripe apples of other varietals.

I recommend everything that promotes good yeast health:

• Proper pitch rate (looks like you over-pitched)
• Proper aeration/oxygenation
• Yeast nutrients containing zinc, added direct to fermenter e.g. Wyeast nutrient
• Controlling the actual beer temperature during fermentation (not just ambient), personally I would aim for around 65-66°F with US-05

I am curious as to the recommendation to add yeast nutrient directly to the fermenter instead of boil kettle. Just asking as I thought it was common to add to the end of the boil. If there are added benefits to doing fermenter in addition to or in replace of boil, I would love to know about them!

 

[RPh_Guy]

I am curious as to the recommendation to add yeast nutrient directly to the fermenter instead of boil kettle. Just asking as I thought it was common to add to the end of the boil. If there are added benefits to doing fermenter in addition to or in replace of boil, I would love to know about them!

I attempt to leave all the trub in the kettle, racking only clear wort to my fermenter. The trub binds to a lot of the nutrients (e.g. zinc), so they would be left behind. By adding nutrients direct to my fermenter I ensure that they are all actually available to the yeast.

 

[TenaCJed]

Did not think of it that way, thank you!!!

 

[AlexKay]

Thanks! This is all very helpful.

Taste is a funny thing. If you told me I was getting a snakebite (half beer, half cider) I might well drink this stuff, but once it's in my mind as an off flavor I can't.

I'm not 100% convinced it's acetaldehyde; I'd been hoping for other ideas. (It's much more of a sweet apple taste than tart or sour.) But the advice all seems like good practice regardless.

I'm probably not going to use Ahtanum again, even if it's not to blame.

 

[AlexKay]

Update:

I'm still not convinced it was acetaldehyde (too sweet), but (1) for a while it was everywhere, and (2) now it's gone.

I had apple taste in the next APA as well, in my pale lager, and in my cream ale. It may well have been in some of my darker beers as well, but it didn't/wouldn't have come through the roastiness.

I tried different grain bills.
I tried different yeasts, liquid and dry.
I tried starting from RO water and adding minerals.
I tried adding yeast nutrient.
I bought an oxygen tank and began oxygenating.

The thing that I think did the trick was sanitation. I took apart both of my brew buckets, boiled the valves and associated parts, scrubbed everything down, and soaked in hot PBW.

But now it's gone. I'm drinking a lovely apple-free american wheat right now, and my next APA comes out of the fermenter tomorrow.

 

[DVCNick]

When I used way too much yeast nutrient one time I got a strong apple flavor but it was under attenuated by a mile. Did you use yeast nutrient and if so what kind and how much?

 

[RM-MN]

I'm still not convinced it was acetaldehyde (too sweet), but (1) for a while it was everywhere, and (2) now it's gone.

This would be a typical ending for acetaldehyde as the yeast will break it down with time. You might be able to avoid it even showing up by ending your fermentation period a little warmer. Keep the temperature controlled for the first 4-5 days, then let it warm to low to mid 70's for the next week. Yeast work faster when it is warmer but we control the temp during the active part of the fermentation to control the off flavors that the yeast create when allowed to work at the temperature they prefer.