Help diagnosing green/solvent/astringent flavor

[JBrady]

Hey guys my last few brews have had a astringent/solvent green apple flavor/smell to them. The majority of the problem is in the aroma where its most noticeable. Three of my last four beers have had the off flavor. Here is some info to help with the troubleshooting.

1. The 3 beers with the off flavors used corn sugar as part of the fermentable sugar. Never more than one pound of corn sugar was used in the brew. This is also the first time I have used a adjunct sugar as part of the grain bill. The fourth beer was a all barley malt beer and it had no off flavor.

2. The 3 off flavor brews were all session strength english style bitters that used thames valley and dry english ale yeast.

3. The off flavor beers used a burton-esque water profile, but not as extreme as the real burton water profile. They were definitely high in sulfate and low in chloride.

4. The off flavor beers all had mashes in the neighborhood of 148-149 degrees.

Is there anything that I've mentioned here that would have caused this wierd flavor to all the sudden start showing up in my brews? thanks for any info.

 

[bourgeoisbee]

From How to Brew:

Acetaldehyde
A flavor of green apples or freshly cut pumpkin; it is an intermediate compound in the formation of alcohol. Some yeast strains produce more than others, but generally it's presence indicates that the beer is too young and needs more time to condition.

Everything you mentioned doesn't seem to be a cause of it. What temperature did you pitch and ferment at? Maybe not enough O2 when pitching too.

 

[bourgeoisbee]

Astringent can be a contamination - bacteria...could be related to the green apple, might not. It could be from your grain too if you sparged lower than 1.010.

 

[JBrady]

From How to Brew:

Acetaldehyde
A flavor of green apples or freshly cut pumpkin; it is an intermediate compound in the formation of alcohol. Some yeast strains produce more than others, but generally it's presence indicates that the beer is too young and needs more time to condition.

Everything you mentioned doesn't seem to be a cause of it. What temperature did you pitch and ferment at? Maybe not enough O2 when pitching too.

pitch at 70, ferment at 64-68 never less or more. I shake the fermenter after transfering the wort for about 3 or 4 minutes to aerate. I just don't not why its occuring all the sudden now. For months my beers were all awesome commercial quality brews but now somethings amiss. thanks.

 

[JBrady]

Astringent can be a contamination - bacteria...could be related to the green apple, might not. It could be from your grain too if you sparged lower than 1.010.

I'm a no sparger, I add my sparge water directly to the mash before draining and then drain all at one time.

 

[bourgeoisbee]

Do you check the gravity of the water toward the end of the drain?
Was the grain mill consistent?

My guess is contamination without tasting/smelling it, since you were making great beer before. Maybe time for a new bucket or racking cane/tubing. Bacteria can hang out in tiny cracks/scratches that are tough to clean/sanitize.

 

[JBrady]

Do you check the gravity of the water toward the end of the drain?
Was the grain mill consistent?

My guess is contamination without tasting/smelling it, since you were making great beer before. Maybe time for a new bucket or racking cane/tubing. Bacteria can hang out in tiny cracks/scratches that are tough to clean/sanitize.

My drain all comes through at the same gravity since I drain the mash and sparge together all at the same time.


It could very well be time for a new autosiphon or bottling bucket. But isn't it tough to get a bacterial infection after fermentation is completed?

 

[bourgeoisbee]

It's definitely harder to get an infection with alcohol present. That's why maybe it's your fermenting vessel. How do you chill and transfer to your fermenter? Something in that process prior to fermentation could be the source.

 

[JBrady]

I chill with a immersion chiller which is introduced to the wort with 30 minutes left in the boil. Once its chilled to about 120 degrees I put the kettle in a ice bath also to help get down to 70. My better bottles have been used for around 2 years but I have 3 bad beers using two different better bottles. Well their not bad beers, they are very drinkable, just not quite right.

 

[bourgeoisbee]

Is there tubing the wort goes through from kettle to better bottle? Maybe take apart and clean the ball valve on your kettle. That seems like the only possibilities to me since it was 2 different better bottles.

 

[JBrady]

Is there tubing the wort goes through from kettle to better bottle? Maybe take apart and clean the ball valve on your kettle. That seems like the only possibilities to me since it was 2 different better bottles.

No I manually pour my kettle into the better bottle using a funnel that lives in a pot of star san for the entire length of the boil.

 

[bourgeoisbee]

Well if it is a contamination issue you've got me stumped. Do you use new star san every time or reuse for a few batches? If you're reusing, that's the only source I see left.

A pound or less of corn sugar shouldn't give you this much of an off flavor, but that seems to be the only thing consistent with the three batches and different than all the other beer you've brewed. Maybe you're really sensitive to it. Do others detect the off flavors?

Were the 3 bad batches the first time you tried to burtonized your water?

 

[Rip]

How long since pitch date and/or bottling?


- M

 

[JBrady]

4 weeks in primary, 2 weeks in bottles. Usually at 2 weeks in the bottle I move the beer into cold storage for the remainder of its life, but with the greenish flavors that these have, they are still at room temperature.

 

[Yooper]

I think solvent/astringent can be related to water chemistry while the apple flavor may be a different issue.

Using a high % of sugar for fermentables can cause the apply flavor- what % of simple sugars did you use?

Did your water chemistry recently change? It sounds like too much sulfate can be an issue, but we'd have to see a recent water profile. I know sometimes in the spring some water suppliers may chlorinate more heavily, or maybe switch to chloramines (which don't boil off).

 

[JBrady]

I think solvent/astringent can be related to water chemistry while the apple flavor may be a different issue.

Using a high % of sugar for fermentables can cause the apply flavor- what % of simple sugars did you use?

Did your water chemistry recently change? It sounds like too much sulfate can be an issue, but we'd have to see a recent water profile. I know sometimes in the spring some water suppliers may chlorinate more heavily, or maybe switch to chloramines (which don't boil off).

I use distilled water + salts and I was high on the sulfates. I don't have my exact numbers in front of me but we may be on to something here. As far as % of sugars it was 1 pound in 3.9-4.2 percent abv beers, again I don't have exact numbers in front of me. thanks.

 

[Yooper]

I use distilled water + salts and I was high on the sulfates. I don't have my exact numbers in front of me but we may be on to something here. As far as % of sugars it was 1 pound in 3.9-4.2 percent abv beers, again I don't have exact numbers in front of me. thanks.

I'd make the same recipe, but revamp the wter chemistry. I'd also consider using a far less % of simple sugar. A pound in a 4% beer would be over 14% sugar in my system.

 

[JBrady]

I'd make the same recipe, but revamp the wter chemistry. I'd also consider using a far less % of simple sugar. A pound in a 4% beer would be over 14% sugar in my system.

One of those two things is more than likely my problem. Will a absence of chlorides make problems worse? I seem to recall when trying to make these drier more chuggable beers that not only was my sulfate high, but my chloride was very low to non existent.

 

[Yooper]

One of those two things is more than likely my problem. Will a absence of chlorides make problems worse? I seem to recall when trying to make these drier more chuggable beers that not only was my sulfate high, but my chloride was very low to non existent.

I've been studying up on water chemistry, but I'm far from an expert! I will say this- chloride/sulfate ratio isn't terribly important and it's mash pH that IS important.

If you're mash pH is too high, and you're using gypsum besides, I can see some harsh astringent flavors resulting.

I'd start over with the water chemisty- using all RO water with maybe a teaspoon of CaCl2 for the next batch. I'd either go with all malt, or cut the sugar by a large margin. I think that will fix any issues. If you have access to a pH meter and can check your mash pH, that would be great. Otherwise, some of those spreadsheets are pretty good at predicting them I understand. Step away from the sulfate, though! If you absolutely positively feel you must use it, then make sure it's a modest amount and only enough to bring up the calcium if needed.

 

[JBrady]

I've been studying up on water chemistry, but I'm far from an expert! I will say this- chloride/sulfate ratio isn't terribly important and it's mash pH that IS important.

If you're mash pH is too high, and you're using gypsum besides, I can see some harsh astringent flavors resulting.

I'd start over with the water chemisty- using all RO water with maybe a teaspoon of CaCl2 for the next batch. I'd either go with all malt, or cut the sugar by a large margin. I think that will fix any issues. If you have access to a pH meter and can check your mash pH, that would be great. Otherwise, some of those spreadsheets are pretty good at predicting them I understand. Step away from the sulfate, though! If you absolutely positively feel you must use it, then make sure it's a modest amount and only enough to bring up the calcium if needed.

I use the ez water spreadsheet thats so popular here to make sure I get the right mash ph for the grain bill. I use those cheap ph test strips and am consistantly hitting 5.0 instead of 5.2 but it doesn't seem to hurt my eff. I think my next beer I will use a CaCl2 oriented water profile, but what about all the nutrients I'll be missing out on by not using epsom salt for magnesium? Is this not as big an issue as I've been led to believe? I do use a generous portion of wyeast yeast nutrient to get things that the distilled water doesn't have like zinc into the beer. Not sure why, but I heard that the brew needs it, lol.

 

[Walker]

I've been studying up on water chemistry, but I'm far from an expert! I will say this- chloride/sulfate ratio isn't terribly important and it's mash pH that IS important.

If you're mash pH is too high, and you're using gypsum besides, I can see some harsh astringent flavors resulting.

I've been doing my studying lately, too, and the chloride:sulfate ratio seems to be fairly important based on what I've read. I'm now doctoring my water to keep that ratio close to 1.00 (balance between malty and hoppy) and might start tweaking and diverging from that to go above or below based on what I am brewing.

But, I'm not downplaying mash pH by any means. I'd doctoring my grain bill with sour malt to get the pH where I want it, too.

 

[Yooper]

I've been doing my studying lately, too, and the chloride:sulfate ratio seems to be fairly important based on what I've read. I'm now doctoring my water to keep that ratio close to 1.00 (balance between malty and hoppy) and might start tweaking and diverging from that to go above or below based on what I am brewing.

But, I'm not downplaying mash pH by any means. I'd doctoring my grain bill with sour malt to get the pH where I want it, too.

I didn't mean it's not something to consider! But I was so worried about adding salts and getting the "right" water profile and neglected concentrating on mash pH. If the mash pH is right, the beer will pretty good even without much in the way of balancing a chloride/sulfate ratio. Malt itself has calcium and other minerals in it, so even a calcium level under 50 ppm isn't that important.

I'm finding that the less I mess with additions, and simply concentrate on the mash pH and bringing down my alkalinity by diluting with RO water, this has helped me more than anything else!