Smokey Wheaty off taste

[mitcht]

Hey Folks I have a problem thats been ongoing for a while now I cant resolve.

It seems that about 80% of the time I make a keg of beer I am getting smokey wheaty off tastes.
Sometimes I dont get it at all and other times I do. Doesn't seem to matter the recipe, or the fermenter I use.

Im using a Grainfather 220V
Ive taken everything including the pump and all seals out/apart and cleaned.

I spray everything down with star san before and after brewing including all seals.
I use Powdered Brewery wash throughout the grainfather and chiller after making beer followed by a rinse then a rinse of star san through everything which I drain out and let dry.

The beer tastes good going into the fermenter but after fermenting I get these off tastes before kegging. (Although sometimes not at all and is 100% perfect)

An example one one of my brews:
3kg of pilsner malt
200g honey malt
100g dex
24g of cascade
Kevik Yeast (fresh from the pack)

Water is coming from the well, which has no off tastes or smells and when tested years ago was perfect.

Anyone have any suggestions?

 

[mashpaddled]

I know you said the water is fine but sometimes there are compounds in the water you don't taste/smell and don't test for, but fermentation changes them into something you taste. You can rule this out as a factor by brewing with a different water source.

 

[MikeScott]

Do you normally use Kviek yeast? Which strain is it that you're using? What are the differences between this beer and the last beer that tasted fine? Do either of the flavors go away after some time?

It sounds like your sanitization procedures are in good shape, I'm leaning towards yeast / fermentation, but Kviek likes it hot, or maybe you're picking up some air in your auto siphon (look for bubbles in the line coming in at the connections). I'm wondering if it's oxidation or acetaldeyhde. Most people describe it as green apple flavor, but it doesn't taste like that to me.

I would suggest leaving the keg out at room temp for a week or so, and then try it again and see if the flavor has gone away or subsided, and on the next batch take a look at the auto siphon, plus, purge the keg before you rack into it.

@mashpaddled has some good advice too. Maybe even try a batch with RO water?

 

[mitcht]

I know you said the water is fine but sometimes there are compounds in the water you don't taste/smell and don't test for, but fermentation changes them into something you taste. You can rule this out as a factor by brewing with a different water source.

Ill give that a try. What specifically in the water could cause this?

 

[mitcht]

Do you normally use Kviek yeast? Which strain is it that you're using? What are the differences between this beer and the last beer that tasted fine? Do either of the flavors go away after some time?

It sounds like your sanitization procedures are in good shape, I'm leaning towards yeast / fermentation, but Kviek likes it hot, or maybe you're picking up some air in your auto siphon (look for bubbles in the line coming in at the connections). I'm wondering if it's oxidation or acetaldeyhde. Most people describe it as green apple flavor, but it doesn't taste like that to me.

I would suggest leaving the keg out at room temp for a week or so, and then try it again and see if the flavor has gone away or subsided, and on the next batch take a look at the auto siphon, plus, purge the keg before you rack into it.

@mashpaddled has some good advice too. Maybe even try a batch with RO water?

Hey Mike
I'm using Mangrove jacks yeast, same brand ive always used previously. Other beers with different yeast do the same thing.

When you say picking up some air in your auto siphon can you describe more what that means? Do you mean when pumping the beer from the grainfather into my SS fermenter? Wouldn't it just having the lid off the fermenter while this happens expose it to air?

The flavor doesn't seem to change once it goes in the keg, even if left out at room temp.

 

[mitcht]

Do you normally use Kviek yeast? Which strain is it that you're using? What are the differences between this beer and the last beer that tasted fine? Do either of the flavors go away after some time?

It sounds like your sanitization procedures are in good shape, I'm leaning towards yeast / fermentation, but Kviek likes it hot, or maybe you're picking up some air in your auto siphon (look for bubbles in the line coming in at the connections). I'm wondering if it's oxidation or acetaldeyhde. Most people describe it as green apple flavor, but it doesn't taste like that to me.

I would suggest leaving the keg out at room temp for a week or so, and then try it again and see if the flavor has gone away or subsided, and on the next batch take a look at the auto siphon, plus, purge the keg before you rack into it.

@mashpaddled has some good advice too. Maybe even try a batch with RO water?

As per the "what is different" - nothing I am aware of.

One thought I did have is I have wirlfloc I use thats about 1 year old, but looks, smells and feels fine. I would typically use this in every beer.. but possible I forgot time to time. I dont know if the times I forgot match with the times its good.. but just throwing that out there.

 

[mitcht]

One other thought.. could fermenting Kviek too cold cause this? I typically ferment on the low range, closer to 20c but it says 20-40 is fine, but optimal is 30+

 

[MikeScott]

Hey Mike
I'm using Mangrove jacks yeast, same brand ive always used previously. Other beers with different yeast do the same thing.

When you say picking up some air in your auto siphon can you describe more what that means? Do you mean when pumping the beer from the grainfather into my SS fermenter? Wouldn't it just having the lid off the fermenter while this happens expose it to air?

The flavor doesn't seem to change once it goes in the keg, even if left out at room temp.

I meant air in the auto siphon when you're going from fermenter to keg. How do you get it from the SS fermenter to the keg?
If you look at the flow from the tubing, make sure you're not getting air bubbles in the flow. If so, take a close look at the beer as it passes by where tubing connects to the autosiphon, if it's not connected really well, it can pull in air as the beer flows past. You'll see bubbles appearing after the joint.

When I asked about which Kviek, I meant more along the lines of what strain, like Hornindal, Voss, etc. I'm not real familiar with Mangrove Jack's offerings. If the off flavor is across multiple yeasts, then that's probably not it, and if the flavor doesn't go away, then it's not likely acetaldeyhde.

I would think that 20C would be just fine, if you're in the range recommended, then you should be good. It wouldn't hurt to try it dead center of the range though, just to see. If it were me, if there's no air in the auto siphon or if you transfer some other way into vented kegs, then I would try using RO water.

 

[mitcht]

I meant air in the auto siphon when you're going from fermenter to keg. How do you get it from the SS fermenter to the keg?
If you look at the flow from the tubing, make sure you're not getting air bubbles in the flow. If so, take a close look at the beer as it passes by where tubing connects to the autosiphon, if it's not connected really well, it can pull in air as the beer flows past. You'll see bubbles appearing after the joint.

When I asked about which Kviek, I meant more along the lines of what strain, like Hornindal, Voss, etc. I'm not real familiar with Mangrove Jack's offerings. If the off flavor is across multiple yeasts, then that's probably not it, and if the flavor doesn't go away, then it's not likely acetaldeyhde.

I would think that 20C would be just fine, if you're in the range recommended, then you should be good. It wouldn't hurt to try it dead center of the range though, just to see. If it were me, if there's no air in the auto siphon or if you transfer some other way into vented kegs, then I would try using RO water.

I gotcha! I'm actually getting the off tastes before I even keg it. If I take a sample from the fermenter it's already there.

 

[MikeScott]

I gotcha! I'm actually getting the off tastes before I even keg it. If I take a sample from the fermenter it's already there.

That's right, sorry, I forgot you mentioned that. I would go with the water.

 

[mitcht]

That's right, sorry, I forgot you mentioned that. I would go with the water.

We'll give that a try. Thanks for the help!