oxidation at dough in?

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slugsly

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I've noticed what I think is oxidation in my beers. I'm going to send one into a competition to get an expert opinion, but I'm pretty sure that's what it is.

I do biab. I've been transfering to secondary (if I do one) and to the serving keg with co2 so I'm pretty sure its happening in my brewing process. It seems to me when I initially put the grain in I really have to mix to get all the dough balls out. Is there a way to minimise all the air that gets in in this initial stir? I try to only gently mix once or twice during my typical 60 minute mash. I also have been boiling very vigorously, but I figure if this oxidizes the wort other people would have trouble too.

I maybe over do it moving my immersion chiller around trying to speed up cooling. I move it around once in a while and sometimes gently stir the wort to speed up cooling.

The beers aren't undrinkable. I think its pretty slight but I want to do better :)
 
Are u adjusting your pH? What water are you using? If your purging your secondary and keg I agree its not oxidizing there. Stirring mash wouldnt give you much hot side aeration. Normally hot side aeration occurs when you have liquids flowing from vessel to vessel splashing into the liquid. Stirring your wort while cooling shouldn't hurt either.

I would look into your water and mash pH
 
Highly unlikely oxidation would occur at dough in .. I like what emyers suggests about looking at water and PH. Just curious - are you full volume mashing with BIAB? I can't think of ever having an issue with dough balls when using FVM.
 
It's unlikely to be during your dough-in. When you boil it removes a lot of free oxygen from the liquid. I had a similar issue once and it turns out the grain I was using was past its prime, but the beer tasted oxidized. Your other processes listed sound fine.
 
I do full volume mash. PH last mash was 5.5. Due to my water not being great I do 90% RO, 10% filter tap water and some salt additions(gypsum, calcium chloride, and Epsom salts).

Maybe the flavor im bothered by isnt oxidation.
 
It tastes what I imagine wet paper tastes like but I've never tasted wet paper. Is the taste of oxidation really like wet paper?

I can't see what I'm doing differently than any other BIABer. I thought maybe it could be stale grain but I've tried a few different sources of grain with the same results.
 
The fact that it's pre-boil makes me doubt it's the dough-in stirring. Boiling removes a LOT of oxygen.

Is there anything happening on the way to the fermenter?

How about the kegs? Are you purging out oxyggen before you carbonate, and before you bottle?
 
I've been fermenting in kegs and pushing to secondary or serving keg with co2. I try to purge the keg of air with co2. The last thing I made I never moved out of primary and tasted some after a 2 weeks. There's no way it was exposed to air and I still taste the off flavor. This was an ipa. This off flavor seems to really blunt hops. Is that a symptom of oxidation?

I make a starter using DME and don't decant. Is it possible somehow I'm making a messed up starter that's adding off flavors? My last starter was 2 litres into 5 gallons of wort.
 
Don't know if this is your issue but 2 L in 5 gal is a lot. Have you ever tasted starter wort? Nasty. I would decant. For reference, in Yeast they recommend decanting if the starter is > 5% of your batch size (you're over 10%).

Edit: regarding the other part of your question, it's not that you're messing up with the starter. They are little batches that are continually oxygenated, fermented fast with a huge pitch rate and without temp control - they always taste nasty.
 
You cannot oxidize a beer pre-fermentation, you actually want to add oxygen to the wort prior to pitching the yeast, so that they ferment cleanly/quickly. Many people use air stones and oxygen tanks to do this.
 
I oxygenate with an oxygen tank. I get that the yeast need it.

In a lot of basic brewing how to's I see warnings to avoid agitation because of hot side aeration. Has this been debunked more or less?

I hadn't decanted my starter because many people say they don't bother but I haven't tasted their beers :) I'm definitely going to try another batch next weekend and decant.
 
I oxygenate with an oxygen tank. I get that the yeast need it.

In a lot of basic brewing how to's I see warnings to avoid agitation because of hot side aeration. Has this been debunked more or less?

I hadn't decanted my starter because many people say they don't bother but I haven't tasted their beers :) I'm definitely going to try another batch next weekend and decant.

Hot side aeration is one of those topics that will probably be debated for an eternity.

My personal experience and observation leads me to believe that if it does exist it has no impact on the flavor of my beer. You see, I dump everything hot, straight from my kettle into the fermenting bucket. I pour it from a few feet up to splash it around as much as possible.

Other reference points are all those folks who do the no chill method with those cube type containers. They dump it in hot, put the lid on and give it a really good shake to sterilize the inside of the container.

My two cents. Someone might chime in and say I'm full of bunk, but I'll happily keep doing it this way unless I find an even quicker, hassle free method.
 
In a lot of basic brewing how to's I see warnings to avoid agitation because of hot side aeration. Has this been debunked more or less?

Here's my favorite hsa exbeeriment He basically concludes that it has no effect.

Since we're not sure that you are actually tasting oxidation it's hard to be certain, but cold crashing the starter is probably the best idea I've seen on this thread.
 
Still had the off flavor after decanting/cold crashing the starter. It is kind of a grainy after taste.

I ferment at 60F in my basement. I used 1332 last time. Is it possible fermentation isn't finishing up at this lower temp?
 
Still had the off flavor after decanting/cold crashing the starter. It is kind of a grainy after taste.

I ferment at 60F in my basement. I used 1332 last time. Is it possible fermentation isn't finishing up at this lower temp?

I'd say it is quite possible. Try a week in the low 70's and see if you notice a different taste or a lower FG. If so, that's your answer.

I usually start my ferments in the low 60's and after a week let them warm to the 70's for another 2 or more weeks.
 
Still had the off flavor after decanting/cold crashing the starter. It is kind of a grainy after taste.

I ferment at 60F in my basement. I used 1332 last time. Is it possible fermentation isn't finishing up at this lower temp?

Do you do any measurements of your mash PH? or do you know the PH of your base water to be able to estimate?

Grainy makes me think maybe the mash PH is off and your extracting tannins from the hulls. Which is why it would be this universal batch to batch off flavor but not seem to be a fermentation flaw.

Not finishing I think would be overly sweet.
 
Don't know if this is your issue but 2 L in 5 gal is a lot. Have you ever tasted starter wort? Nasty. I would decant. For reference, in Yeast they recommend decanting if the starter is > 5% of your batch size (you're over 10%).

Edit: regarding the other part of your question, it's not that you're messing up with the starter. They are little batches that are continually oxygenated, fermented fast with a huge pitch rate and without temp control - they always taste nasty.

This is what I would suspect. Especially if you are making the starter "properly" by trying to areate it and/or using a stir plate.

Its going to funk up your brew. Heck, I cold crash it 24hrs in advance and I decant ALL of the starter (okay, there might be a few ml left). I take my sanitized 1/2 cup meaure that I am using for gravity readings (to fill my graduated cylinder) and I dump a half cup of wort once it is cooled, before transfering it to swirl around in the flank to get all of the yeast in to suspension and then pour it in to my wort.

I don't need any of that nasty starter getting in to my finished beer.
 
On my current beer using wyeast 1332 with a decanted starter fermentation slowed down significantly after 3 days. OG was 1.063. I let it go 2 weeks in my basement at 62F. At this point I was getting maybe a bubble every 30 seconds in my blow off tube. This one I fermented in a bucket and moved it to a keg being careful not to splash around. FG was 1.022. I could taste the off flavor at this point but it was very mild and not really unpleasant. Hop character was strong. I put this keg upstairs where it is 70F and after a day found it was pressurizing due to maybe fermentation taking off again? I let it sit a week. FG dropped more to 1.015. Tasted it and found it to be significantly worse. The off flavor was much stronger, hop character was okay but not as sharp. Overall it's drinkable but dull. My thoughts are that maybe I need to ferment at 64F for a few days then bump it up to 70 and let it sit for a 2-3 weeks? But I'd like to hear people thoughts on how I am messing up :)
 
Two thoughts on off flavors....

1 Be sure you are nailing down the easy stuff before worrying about things like HSA which may be a myth at our scale.

2 The easy stuff is making sure you are getting a decent mash PH and that you are really controlling your fermentation temps.

It honestly sounds like you have nailed down your transfer process to eliminate oxygenation there. One thought would be to eliminate the move to secondary. it is just one more opportunity to introduce O2.

My other thought would be trying to control your fermentation temps better. 62 ambient in your basement is good, but if you have a strong ferment, you could go quite a bit higher in the bucket. I try to keep my ferm chamber in the high 50's for the first 72 hours when I want a fermentation in the low 60's. after that I let it free rise to actual ambient to let the yeast finish up. Helps produce a clean yeast profile.

Also, check your water PH. I had weird flavors before I started using Brun water to predict my PH. It isn't exact without a PH meter to verify but the quality has definitely improved. It could help you too.
 
I measured a ph 5.8 at the end of my last mash. I don't trust my ph meter all the much and I'd guess it's += 0.1. I'll shoot for lower next time.
 
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