Oxidation When Dry Hopping, I Think

[FruityHops]

[Sigh]

I've brewed two batches of home brew now, and last night I confirmed my second batch is suffering the same fate as the first.

I'm beginning to think oxidation might be my problem because both batches have been fine for the first few days to a week in the fermenter, but then they have a green apple flavor after I remove my dry hop bag.

I boil water with the hop bag and some marbles for weight and a string for retrieval, covered for 10 minutes and then let them cool while covered. Then I put the hops in the bag, take the lid off my fermenting bucket, take a sample with a sanitized glass thief, put the hop bag in, and replace the lid.

When I pry the lid off I can see airlock fluid (and air?) getting sucked into the bucket and I have the lid completely off so I can reach in to take the sample. Maybe these two things are the main problems? This second batch is 3 gallons in a 6.5 gallon bucket, so there is a lot of head space.

Anyway, the sample on the day when I add the dry hops has been fine both times. The second batch was really good actually. Then when I remove the hop bag and take another sample just four days later there is a noticeable off flavor that I can best describe as green apple. Yesterday I took another sample from the second batch and confirmed that the green apple flavor is clearly still there (2 days after removing hop bag) and in both cases the hop aroma from dry hopping has not been what I would expect.

I read that green apple flavor is from acetaldehyde and the yeast might clean it up so I left the first batch in the fermenter for a total of 5 weeks. It never cleaned up and even after two weeks bottle conditioning and another month in the bottles it still tastes like green apple crap.

I'm so bummed the second batch has suffered the same fate. First batch was extract with steeping grains and dry yeast. Second batch is all grain BIAB with liquid yeast and starter, in a temp controlled chest freezer using a thermowell.

The fact that both batches are so different and went bad only after adding dry hops makes it clear to me that my next batch needs to be done without any dry hopping, and I'm not going to take any samples either. I'm simply going to let it ferment without touching it at all and then only take a sample when bottling.

If that comes out better then I'll probably try dry hopping in a keg and purging with CO2. I don't own kegging equipment yet though, and I'll only buy that if I can make sure I can brew decent beer first.

Anyone have any input that might help me?

 

[FruityHops]

It also might be worth noting that, even though I used more marbles the second time, both times the hop bag sank when I put it into the fermenter but was floating when I took it out four days later.

 

[Build]

It doesn't sound like oxidation. You'd have to shake the beer up to oxidize it much. You're right, green apple is usually acetaldehyde, many times from young beer. I've had hops that were fine in a boil and flameout, but had grassy flavors when dry hopped. Maybe it's a fresh veg/grass flavor? How are you oxygenating the wort pre fermentation? Under pitched yeast or lack of oxygen can give strong green apple.

 

[FruityHops]

I'm just pouring the wort out of the kettle and letting it splash into the fermenting bucket for aeration/oxygenation, nothing else.

I drink a lot of dry hopped commercial beers and I'm only dry hopping four days, I don't think it is vegetal or grass flavor from the hops.

Supposedly acetaldehyde can come from oxidation so that is my best guess as of now : https://www.homebrewtalk.com/wiki/index.php/Acetaldehyde

 

[agrazela]

What kind of yeast, and what kind of fermentation temperature control do you use?

 

[FruityHops]

The first batch was US-05 with no temp control in 64 degrees ambient.

For the second batch I used Wyeast 1318, London Ale III and an Inkbird dual stage controller with the probe in a thermowell that is submerged in the beer. A chest freezer provides the cooling and a small ceramic heater provides the heat. I set the temp to 66 for two days, 67 for one day, 68 for five days (one day before dry hopping and then the four days of dry hopping). It is now set to 69 and has been there for three days. The three piece airlock stopped bubbling around day three, when temp was at 67.

 

[urg8rb8]

Give the beer more time to age out. Many of my beers would taste good at first then start tasting funky.. then a few weeks later taste awesome!! Give it some time!

 

[Build]

I'm just pouring the wort out of the kettle and letting it splash into the fermenting bucket for aeration/oxygenation, nothing else.
]

I think you need more oxygen. When I aerate without a pump I will vigorously shake the wort for 3-5 minutes.

I agree with urg8rb8, more time will help a lot of beers. If yours is oxidized it will taste worst as time goes by. Are you getting any damp cardboard flavor/smell?

 

[JJ900]

What kind of hops were you dry-hopping with? Any chance they are a flavor you don't like?
And for safety's sake you may not want to ferment with so much head space.

 

[shortyz]

Give the beer more time to age out. Many of my beers would taste good at first then start tasting funky.. then a few weeks later taste awesome!! Give it some time!

^^^^ this.

 

[FruityHops]

Give the beer more time to age out. Many of my beers would taste good at first then start tasting funky.. then a few weeks later taste awesome!! Give it some time!

I hope that is all that is going on, unwarranted newbie worries. Only time will tell.

I gave this second batch less time (2 weeks) in primary since 5 weeks didn't seem to help the first batch. I will give the new batch at least 3 weeks of bottle conditioning at 70F to see if that helps. The first batch had 2 weeks of bottle conditioning before I put them in the fridge and they still tasted off at that time. Now that I've taken the first batch out of the fridge (2 months later) and given them 2 more weeks at room temp the green apple flavor seems to have subsided.

I wish I could find a way to prevent the green apple flavor and have a quicker turn around since these hoppy pale ales and IPA's are better fresh. Maybe in the end I'll be dry hopping later on, just before bottling or kegging.

I'm still thinking I'll try my next fermentation with no dry hopping and leave it untouched for 3 weeks to see what that is like. Probably going to wait and see how this turns out before I brew again though.

 

[FruityHops]

I think you need more oxygen. When I aerate without a pump I will vigorously shake the wort for 3-5 minutes.

I agree with urg8rb8, more time will help a lot of beers. If yours is oxidized it will taste worst as time goes by. Are you getting any damp cardboard flavor/smell?

I'm also going to make sure I at least aerate the next batch very well, or maybe even buy an O2 setup. It can't hurt and it certainly could be part of the problem.

I'm not getting and damp cardboard flavor or smell, even from the first batch that is over 2 months old now. So it is probably either young beer or a lack of early oxygenation, rather than oxidation when dry hopping.

 

[FruityHops]

What kind of hops were you dry-hopping with? Any chance they are a flavor you don't like?
And for safety's sake you may not want to ferment with so much head space.

The first batch was citra and amarillo. The second batch was citra and mosaic. I'm pretty sure they're hops that I like, but this is all pretty new to me.

 

[thedon986]

What was the quantity of hops in the boil? and dry hops? Also, what water are you using? Straight from the tap? I had a similar off flavor for all my IPAs and narrowed it down to my water source. I switched to RO with mineral additions and no more off-tasting IPAs.

Check this out: http://www.beeradvocate.com/community/threads/off-flavor-in-ipas.125055/

 

[FruityHops]

First extract batch was tap water. Second BIAB batch was 5 gallons distilled water with 5.5g CaCl and 5g gypsum added to get about 140ppm each of Ca, Cl, and SO4.

Second batch had 10g magnum @60 min, .5oz citra @ 5 min, .5oz mosaic @ 5 min, 3oz citra whirlpool, 3oz mosaic whirlpool. Dry hopped with 1.5oz citra and 1.5oz mosaic on day 4 for a length of 4 days. This was a 3 gallon batch.

 

[kh54s10]

First extract batch was tap water. Second BIAB batch was 5 gallons distilled water with 5.5g CaCl and 5g gypsum added to get about 140ppm each of Ca, Cl, and SO4.

Second batch had 10g magnum @60 min, .5oz citra @ 5 min, .5oz mosaic @ 5 min, 3oz citra whirlpool, 3oz mosaic whirlpool. Dry hopped with 1.5oz citra and 1.5oz mosaic on day 4 for a length of 4 days. This was a 3 gallon batch.

Seems like a huge amount of hops in the whirlpool. Especially for a 3 gallon batch. Try cutting that addition in half or even less.

 

[yeahfairly]

[Sigh]

I've brewed two batches of home brew now, and last night I confirmed my second batch is suffering the same fate as the first.

I'm beginning to think oxidation might be my problem because both batches have been fine for the first few days to a week in the fermenter, but then they have a green apple flavor after I remove my dry hop bag.

Are you dry Hopping during primary fermentation..... or are you waiting until you get to FG and then adding them? Sorry for asking but I can't tell from your post.

 

[FruityHops]

Seems like a huge amount of hops in the whirlpool. Especially for a 3 gallon batch. Try cutting that addition in half or even less.

Yup, it was a lot. What might the problem be with using that much hops in the whirlpool?

 

[FruityHops]

Are you dry Hopping during primary fermentation..... or are you waiting until you get to FG and then adding them? Sorry for asking but I can't tell from your post.

It was during active fermentation, in the primary (only) vessel. OG was 1.054, gravity when I dry hopped on day four was 1.018. Gravity after four days of dry hopping was 1.015, which was also the final gravity.

 

[kh54s10]

Yup, it was a lot. What might the problem be with using that much hops in the whirlpool?

I don't know if there is anything wrong.

It just seems like a huge amount to me. I don't use that much in my 5 gallon batches.

 

[JJ900]

there may not be anything wrong with that large amount of dry hops but since you are trying to eliminate variables it might make sense to brew a batch from a decent looking kit using it like a baseline recipe, then you can see how that tastes. Because it sounds like you are going with hopping rates that are more aggressive and you might benefit from just a good normal IPA recipe, get that to come out right, then ramp back up to more aggressive dry hopping on future batches. Also, maybe your fermentation length before bottling e.g. on batch # 2 was a little quick, let it go up to two weeks, just to make sure that's not the problem.