Help me figure out why all my beers seem to have acetaldehyde

[h22lude]

I have been having a problem with what I think is acetaldehyde in my beers. To me it tastes just like fake green apple, almost candy-ish. Every single beer has had it lately. I can't figure out why and it is getting really frustrating almost to the point of me wanting to stop brewing.

I BIAB with a Brew Boss system. Everything is cleaned well after each batch. I was using my tap water but recently just bought a RO system and used Bru'n water to get my mineral additions. I bought a glass carboy instead of using my plastic buckets. I started racking to my kegs using a closed transfer with CO2. All my batches I let ferment for 2 weeks and carb at 12psi for 2 weeks. Most batches I can smell it at racking to keg but some I can't until it has been carbed in my keg.

I can't think that it would be my process. I clean and sanitize well. Mash temps are spot on with Brew Boss. Fermentation temp is spot on with STC-1000 and a fridge.

Could using old yeast cause this? I noticed the last yeast I just used from my lhbs was packed on 2/24/16 and best by 8/22/16. I brewed on 7/28/16. I did make a starter. I'm wondering if the yeast I am getting from my lhbs is slightly older. I have used all different yeasts which makes me think it isn't the yeast.

I can't think of anything else as to why I am always getting this aroma and flavor. The batch I just brewed on 7/28/16 had it right from the fermentor. I bottled half and kegged half to see if it was my kegging system. I also put some in a bottle and didn't carb it. I just tasted that bottle and that aroma and flavor comes through a lot. I could leave it to ferment for 3 weeks but it should be done at 2 weeks especially since it always gets down to my FG.

 

[FirstAidBrewing]

Are you pitching enough yeast for your brews? Underpitching can produce those compounds.

What about aeration of wort prior to pitching? I didn't see a mention of your practices there.

 

[55x11]

I have been having a problem with what I think is acetaldehyde in my beers. To me it tastes just like fake green apple, almost candy-ish. Every single beer has had it lately. I can't figure out why and it is getting really frustrating almost to the point of me wanting to stop brewing.

I BIAB with a Brew Boss system. Everything is cleaned well after each batch. I was using my tap water but recently just bought a RO system and used Bru'n water to get my mineral additions. I bought a glass carboy instead of using my plastic buckets. I started racking to my kegs using a closed transfer with CO2. All my batches I let ferment for 2 weeks and carb at 12psi for 2 weeks. Most batches I can smell it at racking to keg but some I can't until it has been carbed in my keg.

I can't think that it would be my process. I clean and sanitize well. Mash temps are spot on with Brew Boss. Fermentation temp is spot on with STC-1000 and a fridge.

Could using old yeast cause this? I noticed the last yeast I just used from my lhbs was packed on 2/24/16 and best by 8/22/16. I brewed on 7/28/16. I did make a starter. I'm wondering if the yeast I am getting from my lhbs is slightly older. I have used all different yeasts which makes me think it isn't the yeast.

I can't think of anything else as to why I am always getting this aroma and flavor. The batch I just brewed on 7/28/16 had it right from the fermentor. I bottled half and kegged half to see if it was my kegging system. I also put some in a bottle and didn't carb it. I just tasted that bottle and that aroma and flavor comes through a lot. I could leave it to ferment for 3 weeks but it should be done at 2 weeks especially since it always gets down to my FG.

hard to say why but usually reasons for acetaldehyde are:
1. poor sanitation (seems to be NOT your problem)
2. inadequate pitching rate
3. taking beer off the yeast too soon
4. oxidation

How big are your batches and your starter? How long do you let it go before pitching? Do you decant?

Do you oxygenate your wort prior to pitching?

Maybe leaving the beer on the yeast for another week is not a bad test. 2 weeks should be enough assuming you have sufficient amount of healthy yeast.

I would ramp up the temperature in the final few days/week to let yeast cleanup after itself. Acetaldehyde is produced in every fermentation process, it's yeast' job to clean it up below observable levels.

 

[jekeane]

I think you need to get a sample in the hands of some judges or people with trained palates. To me acetaldehyde is like a granny smith apple not like jolly rancher green apple. Maybe go buy one and try it along side your beer.

 

[h22lude]

Are you pitching enough yeast for your brews? Underpitching can produce those compounds.

What about aeration of wort prior to pitching? I didn't see a mention of your practices there.

I use a calculator to determine my yeast count so underpitch is most likely not the issue.

Aeration could actually be something i look at. I do shake to aerate but maybe not enough. I tend to shake for a minute or two.

 

[h22lude]

hard to say why but usually reasons for acetaldehyde are:
1. poor sanitation (seems to be NOT your problem)
2. inadequate pitching rate
3. taking beer off the yeast too soon
4. oxidation

How big are your batches and your starter? How long do you let it go before pitching? Do you decant?

Do you oxygenate your wort prior to pitching?

Maybe leaving the beer on the yeast for another week is not a bad test. 2 weeks should be enough assuming you have sufficient amount of healthy yeast.

I would ramp up the temperature in the final few days/week to let yeast cleanup after itself. Acetaldehyde is produced in every fermentation process, it's yeast' job to clean it up below observable levels.

5.5 gallon batches. I use Mr malty for my yeast count. Usually 1 to 2 liter starters. I let it go for 24 hours then crash for 24 hours and decent most of the wort. I let the rest sit out to warm up and swish it around to get all the yeast.

Aeration might be an issue. I shake for a minute or two which I figured was enough time but may not be. I shake it really hard for the couple minutes.

My temps are usually mid 60s. This last batch i started low but brought it up to 68 for the final week.

 

[55x11]

5.5 gallon batches. I use Mr malty for my yeast count. Usually 1 to 2 liter starters. I let it go for 24 hours then crash for 24 hours and decent most of the wort. I let the rest sit out to warm up and swish it around to get all the yeast.

Aeration might be an issue. I shake for a minute or two which I figured was enough time but may not be. I shake it really hard for the couple minutes.

My temps are usually mid 60s. This last batch i started low but brought it up to 68 for the final week.

so you probably also take into account possible decrease in yeast viability (date of "birth" for yeast)?

Beats me. Your system/approach seems right on the money - similar to what mine used to be, but now I oxygenate with pure O2 and a stone, and my starters are usually around 4L (but I save some yeast for later use).

I would say:
1. pitch on the larger side, just to be safe (I believe over-pitching is not as problematic as under-pitching), maybe make 3L starter next time and pitch the whole thing.
2. Aerate a little longer (but it sounds to be reasonable enough)
3. Leave on the yeast cake until green apple taste disappears?

 

[jcav]

Don't give up! Sometimes it can be related to pitching rate, oxygen and nutrients. Did you use a yeast nutrient when you made your starter and also in your boil kettle? Did you aerate your wort? I use oxygen from a disposable tank and always make a starter with yeast nutrient and put nutrient in the boil kettle also.

My fermentations always take off quickly and I don't rush it and let the yeast clean up after final gravity is reached. I have read that over pitching will cause Acetaldehyde production, and some yeast strains by their nature just produce more of it. If your having problems with a certain yeast strain you may have to select a different strain for your fermenting conditions. Reducing head pressure during fermentation and using a blow off tube will also help blow off the aldehydes as they are easily volatilized, according to what I read. Hope this helps a little....

John

 

[h22lude]

so you probably also take into account possible decrease in yeast viability (date of "birth" for yeast)?

Beats me. Your system/approach seems right on the money - similar to what mine used to be, but now I oxygenate with pure O2 and a stone, and my starters are usually around 4L (but I save some yeast for later use).

I would say:
1. pitch on the larger side, just to be safe (I believe over-pitching is not as problematic as under-pitching), maybe make 3L starter next time and pitch the whole thing.
2. Aerate a little longer (but it sounds to be reasonable enough)
3. Leave on the yeast cake until green apple taste disappears?

Yeah I do enter production date when using Mr malty.

I think my next batch I'll be using us-05 and pitch 2 of them. I may get pure o2 too and leave it for 3 weeks.

 

[jcav]

I would try that also. Get some yeast nutrient for your boil kettle. Fresh yeast, 2 packs for 5 gallons (I would make a starter) Oxygen with a stone for a 60 to 75 seconds. Then let it ride for three weeks. It can't hurt and see if it goes away. At least you'll know what steps you took if it does. I bet it does go away!

John

 

[RM-MN]

Temperature can make a difference in the acetaldehyde. Try warming one of your kegged beers up to the mid 70's for a few days and then chill it again. Sometimes yeast has difficulty breaking down acetaldehyde if it is too cool. For a beer that you are fermenting, use your fermentation chamber to control the temp for about 5 days (varies with OG) and then let the beer warm to low 70's for another 5 to 10 days.

 

[h22lude]

i love me some bud light bitch

Ok I'm trying to quote jcav and this is what I keep getting lol not sure what's happening here.

Anyway, now that you mention it I was using nutrients awhile ago but ran out and never bought more. I can't remember this flavor when I was using it. I think my next batch I'll use nutrients and buy pure o2, which I have been meaning to buy anyway.

 

[h22lude]

I would try that also. Get some yeast nutrient for your boil kettle. Fresh yeast, 2 packs for 5 gallons (I would make a starter) Oxygen with a stone for a 60 to 75 seconds. Then let it ride for three weeks. It can't hurt and see if it goes away. At least you'll know what steps you took if it does. I bet it does go away!

John

Well this quote worked lol it was your first post that didnt.

I may try nutrients and pure o2 and still let it sit for 2 weeks. I want to see if it is time or my aeration. 2 weeks should be plenty of time. if that doesn't work then I'll go to 3 weeks.

 

[h22lude]

Temperature can make a difference in the acetaldehyde. Try warming one of your kegged beers up to the mid 70's for a few days and then chill it again. Sometimes yeast has difficulty breaking down acetaldehyde if it is too cool. For a beer that you are fermenting, use your fermentation chamber to control the temp for about 5 days (varies with OG) and then let the beer warm to low 70's for another 5 to 10 days.

The beer I just brewed I did this. I let it ferment at 63 then slowly brought it up to 68. I typically keg and put it in my keezer to carb. This time I kegged and I'm letting it carb outside my keezer. Hopefully that will help.

I'm going to try all these for my next batch. Using yeast nutrients, pure o2, let it warm up after high fermentation and carb outside my keezer.

Sorry for quotes in different posts. I'm on my phone. It is a pain to copy and paste all into one post.

 

[brewgar]

Have you tried serving your beer at a higher temperature?

 

[h22lude]

Have you tried serving your beer at a higher temperature?

My temp controller is set to 42 right now. Not sure how higher I want to go.

 

[brewgar]

No, no. Try SERVING at higher temp.

 

[h22lude]

No, no. Try SERVING at higher temp.

Like higher 40s? My keezer is what is set to 42 for serving. I like my IPA'S on the colder side. I would think warmer serving temp would bring out the flavor more, no?

 

[ParanoidAndroid]

People are mentioning yeast nutrients, but be aware of which one you purchase.

I know a lack of zinc in the wort can cause acetaldehyde problems. Reverse osmosis and distilled water are devoid of just about everything. Tap water has some zinc in it.

The only yeast nutrient that contains zinc is Wyeast Nutrient. The kind you buy at the LHBS is probably just dead yeast cells, urea, and some other stuff. I'd try some of that also.

 

[h22lude]

People are mentioning yeast nutrients, but be aware of which one you purchase.

I know a lack of zinc in the wort can cause acetaldehyde problems. Reverse osmosis and distilled water are devoid of just about everything. Tap water has some zinc in it.

The only yeast nutrient that contains zinc is Wyeast Nutrient. The kind you buy at the LHBS is probably just dead yeast cells, urea, and some other stuff. I'd try some of that also.

I was using the yeast nutrients from wyeast and plan on buying more. Just checked and it does have zinc.

 

[ParanoidAndroid]

I was using the yeast nutrients from wyeast and plan on buying more. Just checked and it does have zinc.

From Yeast Biotechnology: Diversity and Applications:

"Regarding fermentation, zinc is well known as an essential ion for alcohol dehydrogenase (ADH) (Magonet et al., 1992), which facilitates the conversion of acetaldehyde into ethanol at the end of fermentation."

The way I understand it is that everything you read says to allow the beer to stay on the yeast longer to "clean up" acetaldehyde (amongst other items). Acetaldehyde is converted to ethanol towards the end of fermentation, hence the quote above. However its only converted to desirable amounts if zinc is present.

 

[h22lude]

From Yeast Biotechnology: Diversity and Applications:

"Regarding fermentation, zinc is well known as an essential ion for alcohol dehydrogenase (ADH) (Magonet et al., 1992), which facilitates the conversion of acetaldehyde into ethanol at the end of fermentation."

The way I understand it is that everything you read says to allow the beer to stay on the yeast longer to "clean up" acetaldehyde (amongst other items). Acetaldehyde is converted to ethanol towards the end of fermentation, hence the quote above. However its only converted to desirable amounts if zinc is present.

This may be a big part of my problem. I think with pure o2, letting it warm up after high fermentation and using wyeast yeast nutrient, my problem should be fixed.

 

[ViciousFishes]

If it's Acetaldehyde, good chance ramping temps to allow yeast to clean up after themselves should do the trick. But this also comes to mind:
http://brulosophy.com/2014/11/13/problem-identification-or-helping-a-buddy-stay-in-the-hobby/

When was the last time you tore down and cleaned your ball valves?

 

[h22lude]

If it's Acetaldehyde, good chance ramping temps to allow yeast to clean up after themselves should do the trick. But this also comes to mind:
http://brulosophy.com/2014/11/13/problem-identification-or-helping-a-buddy-stay-in-the-hobby/

When was the last time you tore down and cleaned your ball valves?

Funny you post that because one day about 6 months ago I decided to take it all apart and found a small amount of black gunk. Cleaned it and have been taking my 3 piece ball valve and pump head apart after each brew. That didn't fix the issue. I do have a little valve on my pump that I may need to look at. I'll check that out.

I have my old set up. Pot with no valves and cooler for mash tun. I may brew on that to see if I get the same off flavor. Ever since I found that gunk I have been cleaning it well. Wash out BK. Run pbw through system. Empty BK and rinse it with water. Run water through system. Take apart ball valve and pump. Only thing I'm not sure about is inside CFC but it gets pbw and rinse water so I'd think it would be fine.

I'm feeling similar to wes. I feel like I have done everything to fix the problem but it keeps coming back. This batch I'll be able to tell if it is my kegging system because I bottled half. I'm 99% sure it isnt. I'm hoping it has something to do with yeast, yeast nutrients and aeration. After that, I'm not sure what else to check. I'll need to start testing everything.

 

[jcav]

Wyeast yeast nutrient is the only one I use, so good to know that others say this one has the zinc content needed. Good luck, I hope you get this figured out!

John

 

[h22lude]

At this point the only thing I think I can change is better aeration, ramping up temp and using yeast nutrients. Maybe leave it for 3 weeks but 2 weeks should be plenty of time especially ramping up the temp. I'll report back after my next brew which should be next week.

 

[h22lude]

When does everyone ramp temps? I brewed a stout yesterday. May not be the best to test for off flavors but I wanted to brew it now so it will be conditioned for the start of fall.

Brewed with RO water, used mineral additions, hit 5.5 ph, used wyeast nutrients, used pure o2 and a packet of rehydrated s-04. If this still has the off flavor, I'm not sure what I can change. I am going to take my kettle completely apart including temp probe fitting and sight gauge.

 

[ParanoidAndroid]

When does everyone ramp temps? I brewed a stout yesterday. May not be the best to test for off flavors but I wanted to brew it now so it will be conditioned for the start of fall.

Brewed with RO water, used mineral additions, hit 5.5 ph, used wyeast nutrients, used pure o2 and a packet of rehydrated s-04. If this still has the off flavor, I'm not sure what I can change. I am going to take my kettle completely apart including temp probe fitting and sight gauge.

One thing to note is that the S-04 is an English strain, so fruity characteristics will be present, but that is within the parameters of the yeast. Don't confuse the fruity aspects of the yeast with acetaldehyde off flavor.

If this brew doesn't go well, try these out:

-Change to a very clean/neutral yeast. Maybe 1056 for every brew. This would help take out any yeast flavors and remove a variable.

-Take the starter out of the equation by pitching two packs of 1056. No chance of a starter infection by simply direct pitching.

-Try smaller batches (1-3 gallons). Its not as frustrating, or as expensive, when something goes wrong. Quicker turnaround so more styles to brew.

-If you do 5 gallon batches Get a couple of 2 gallon fermenter buckets. Split the batch after brewing and pitch two different yeasts. That might help get an idea of what the yeasts accomplish.

-Watch oxygen intake all throughout the process. Lot of talk recently on dissolved oxygen levels from the beginning (strike water) to the end (packaging). Minimize splashing whenever possible....like opening distilled water bottles and pouring them into the pot, splashing like hell. Some yeast and dextrose in the strike water for 30 minutes removes a lot of oxygen.

 

[ThirstyPawsHB]

I would recommend brewing a SMaSh Pale Ale, lighter with less ingredients, then use 1 package of US05 (plenty of GOOD yeast for this beer!). Ensure the air/water is around 62-63 for a couple days AFTER activity is noticed. Raise to 65 on day 3 then room temp for remaining time. Do a check of the beer around day 7 (I'm not a fan of doing this normally but will do when troubleshooting issues) then see what you have.

Make sure your pitching at a good temp, <80F maximum, and not killing off yeast.

After cooling and transferring to bucket, I'll (all sanitized mind you!) transfer between containers a couple times to aerate, get a nice rolling foam before pitching.
Good Luck!

 

[ThirstyPawsHB]

are you pitching enough yeast for your brews? Underpitching can produce those compounds.

What about aeration of wort prior to pitching? I didn't see a mention of your practices there.

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