Off flavor issue... HELP!

[robmartin113]

I've been having an issue with some kind of phenolic off flavor and after completely assuring that I did everything by the book this go around, I have no idea where it is coming from.

Background: 4 different brews. All hop forward IPAs have developed different levels of the off flavor. My most recent (by the book) batch has a very faint off taste at the end of a sip. I have brewed other styles and the off taste hasn't been there. Those were a hefeweizen, spiced ale, and a pumpkin ale. I suspect the ester and spice profiles mask off flavors more than an ipa.

I brew all grain. 10 gallon home depot cooler, 8 gallon brew pot, counterclockwise chiller. Sanitation is fine, fermentation Temps all held steady in the mid 60s. All beers brewed with US05.

The only thing that is a little different this time was the use of a yeast starter on a stir plate for 24 hours. I built up the yeast count and then split it between this latest batch in question and a black ipa that is still fermenting (jury still out on that one). And the fact that I used Poland Spring bottled water to rule out the water at my house being the issue.

Anyone have the slightest idea?

 

[phyllobeddo]

I get some sort of spicy flavor from US-05 fermented around 67F. 64F and below I get some sort of peach flavor. I quit using it altogether because of those two reasons. I'm about to brew a few pales with WLP001. We'll see what we get!

 

[DonGavlar]

Hmm well if we were to narrow it down, the first culprit would probably be chlorine. Are you taking measures to remove chlorines before brewing?

Second I would add would be yeast health, are you pitching adequate amounts of yeast, I see you’re using dry yeast, some higher gravity beers may actually require you to pitch a couple satchets of the stuff, are you rehydrating too? Also are you pitching into a nicely aerated evnviroment and at your desired fermentation tempature or below? Perhaps on your next brew use a simple grain bill like a standard pale ale and then use a liquid yeast like wlp001 that isnt known for giving off phenols, make an adequate yeast starter as recommended by mr.malty or some other software and keep tempature under control, see if after that the beer still gives you the off flavour. Atleast that way you can eliminate the yeast as the culprit. Are you fermenting under temp control or just an ambient temp that is in the mid 60’s? I was actually fermenting in a room that is around 66/67F and it wasn’t till a couple batches down the line I realised the actual wort temp was nearer 71/72 during peak fermentation on some brews.

Lastly are you mashing and sparging at the right temps, too high temps can cause these off flavours.

Apart from that, if your sanitation is good, ferm temps low, im not too sure what could be causing it seeing as you’re not using a high phenol producing yeast.

I hope someone else can chime in and help narrow the cause down.

 

[robmartin113]

Hmm well if we were to narrow it down, the first culprit would probably be chlorine. Are you taking measures to remove chlorines before brewing?

Second I would add would be yeast health, are you pitching adequate amounts of yeast, I see you’re using dry yeast, some higher gravity beers may actually require you to pitch a couple satchets of the stuff, are you rehydrating too? Also are you pitching into a nicely aerated evnviroment and at your desired fermentation tempature or below? Perhaps on your next brew use a simple grain bill like a standard pale ale and then use a liquid yeast like wlp001 that isnt known for giving off phenols, make an adequate yeast starter as recommended by mr.malty or some other software and keep tempature under control, see if after that the beer still gives you the off flavour. Atleast that way you can eliminate the yeast as the culprit. Are you fermenting under temp control or just an ambient temp that is in the mid 60’s? I was actually fermenting in a room that is around 66/67F and it wasn’t till a couple batches down the line I realised the actual wort temp was nearer 71/72 during peak fermentation on some brews.

Lastly are you mashing and sparging at the right temps, too high temps can cause these off flavours.

Apart from that, if your sanitation is good, ferm temps low, im not too sure what could be causing it seeing as you’re not using a high phenol producing yeast.

I hope someone else can chime in and help narrow the cause down.

I can't tell for sure that the fermentation temp was in the low to mid 60s. I had them fermenting in my garage which has held at 35 degrees. I have a thermometer taped to the buckets.

The yeast is always rehydrated. On this particular beer, I may have underpitched Bc I split a starter. But I doubt it.

I thought chlorine at first, but this time I used bottled water so that's out.

Mash Temps good. Never go above 170 on sparge/mash out.

I aerate by shaking and the venturi Effect with a temp probe in the out tubing on my chiller. so maybe I didn't do aerate enough. But fermentation started writing 12 hours. For what it's worth. I also pitched at 60 and let it go while monitoring temp as described as above.

 

[robmartin113]

Update.

Ruled out:

Water. Used only bottled Poland spring for an all grain and an extract kit. Both exhibit the off phenols.

Grain crush/mash issue. I heard Improperly milled grain can cause polyphenols in the mash. The off flavor is in the extract kit as well and that did not require milling of grains.

Chiller Infection. I use a homemade counterflow chiller. It's not infected as I had friends share the chiller when I brewed these infected beers and they don't have any issues.

Still in play:

Yeast health. Could be bad batch. Could be poor pitch count. Currently have a starter going on a packet of US 05 of the same yeast batch as the previous.

Fermentation vessel infection. I don't think it is this because I have brewed beers and a cider in the same vessels with US04 that turned out fine. I gave everything a cleaning and soak last night as a good precaution.

I'm leaning toward the yeast. Be it pitch rate or a bad batch. Fwiw, I ordered the 3 pack of 05 and 04 from Amazon so Idk how it was stored, but I have kept it in my fridge. Again, US04 fermented beers and ciders have been fine.

I'll update as I get further into it. If anyone has any other suggestions or has seen posts of similar issues, please let me know.

 

[kh54s10]

Making a starter with dry yeast may be part of the problem. Dry yeasts are not meant to be used by making a starter. Some say that putting the yeast in a wort directly will kill as much as 50% of them right off. So if you made a starter you are killing off yeast cells then producing new cells. You might be back where you started from.

Did your extract recipe include steeping grains? If so were they crushed. If it had some and they were not crushed, they added very little to the beer. They do need to be crushed. I don't know if it would have caused your off flavors.

There was also a thread recently about people who just don't like US05. I use a lot of it. I don't have a very refined taste palate so slight off flavors I wouldn't even notice.

 

[robmartin113]

I've used 05 almost exclusively for my 5 years of brewing.

The most recent 2 patches are the first time I ever made a starter. (new stir plate toy). I usually pitch directly. Sometimes I rehydrate, sometimes not. I've had the phenol issues doing it each way.

The extract kit had steeping grains. I asked for them to be premilled and they were.

And note, this isn't a slight off flavor. It is completely overwhelming.

 

[flars]

I can't tell for sure that the fermentation temp was in the low to mid 60s. I had them fermenting in my garage which has held at 35 degrees. I have a thermometer taped to the buckets.
When I fermented with US-05 in the low 60°F range a peach ester was noticeable in some beer styles.

The yeast is always rehydrated. On this particular beer, I may have underpitched Bc I split a starter. But I doubt it.
Did you rehydrate the dry yeast before adding to a starter wort? 15 minutes hydration on 85°F water then 15 minutes stirred in. Pitching to the starter wort within 30 minutes from the end of the second 15 minute period. Not rehydrating dry yeast for a starter will potentially kill half the yeast cells. Same as pitching the dry yeast into the fermentor.

How many packets of yeast did you use in the starter for the 10 gallons of beer?

I thought chlorine at first, but this time I used bottled water so that's out.

Mash Temps good. Never go above 170 on sparge/mash out.

I aerate by shaking and the venturi Effect with a temp probe in the out tubing on my chiller. so maybe I didn't do aerate enough. But fermentation started writing 12 hours. For what it's worth. I also pitched at 60 and let it go while monitoring temp as described as above.

Problem areas could be under pitching the yeast, inadequate aeration, and then compounded by the cool fermentation temperature. It will be difficult to narrow down the problem with previous ferments if the current beer lacks any off flavors.

 

[robmartin113]

Problem areas could be under pitching the yeast, inadequate aeration, and then compounded by the cool fermentation temperature. It will be difficult to narrow down the problem with previous ferments if the current beer lacks any off flavors.

Interesting. I have never heard o killing of almost half the yeast if direct pitching dry. I was on the forums at probrewer.com and noticed that some breweries do dry pitching. That is what I have done since I started and never had any issues.

If that is the case, then I agree. If I combined underpitching with poor aeration and lower fermenting temps (even though its not a peachy off flavor), then I think I found the cause. Especially since the two current beers exhibit the same bad phenolic taste.

I'm going to make a proper starter tonight with properly rehydrated yeast. Build that up to enough cells to go into a cheap extract IPA kit that I have laying around, and ferment around 68 to see if that solves the problem.

 

[kh54s10]

While you can make starters with dry yeast. There is usually no need. A pack is enough for a 5 gallon batch. A package of liquid yeast is generally not enough to be optimum. Of course any amount of yeast will ferment almost any amount of beer, just not optimally. With liquid yeast at around $9 it is cheaper to make a starter. With dry yeast at about $4 it is about the same (maybe even cheaper) to use another pack as it is to make a starter.

For me, I would just rehydrate the yeast and pitch it in your IPA - one pack.

 

[robmartin113]

That is what I have always done. For some reason, the last few beers have had these bad phenolic flavors.

It could be that I fermented at too low a temperature but I'll have to test that.

 

[kylevester]

What valves do you have and do you ever take them apart to clean?

Ball valves cannot be CIP fully. Small amounts of liquid get in the cavities behind the gaskets. Great places for bugs to grow.

 

[Drk93TT]

1. What are you using for fermentation temp monitoring..? Is it accurate?

2. Sanitation cant be "fine" Id suggest you confidently type that everything is clean and properly sanitized on the cold side.

Other than that your on your own.

 

[c673986]

Check your stir rod for cuts in it, it could get an infection which just grows with the starter. It’s rare to have that much of flavor with 05. I will say I’ve used it several time (10 plus) but I’ve never used a starter.

 

[robmartin113]

Ball valve was completely cleaned and sanitized. As was the hose barb.

Sanitation is excellent on the cold side. Everything is clean as it always is.

I never considered the stir rod. It is brand new with the stir plate set up. I did however soak flask and stir rod in a 200 ppm bleach solution so that should have taken care of any nasties there.

I am really thinking it was a combo of poorly stored yeast by the supplier and then underpitching.

Brewing a test pale ale this Sunday to see if my theory is correct.

 

[robmartin113]

Checking back in for anyone following. I went back and looked at my attenuations over the course of several brews. I noticed that all the brews fermented in my buckets had attenuations in the mid to upper 80's... I knew something was off. The brews done in my better bottles did not have high attenuation or the strange phenolic off flavors.

After more research, I can say with close to 100 percent certainty that I had an infection from a wild brett strain in my buckets. They have been thrown out. Everything else bleach sanitized.

 

[phyllobeddo]

Checking back in for anyone following. I went back and looked at my attenuations over the course of several brews. I noticed that all the brews fermented in my buckets had attenuations in the mid to upper 80's... I knew something was off. The brews done in my better bottles did not have high attenuation or the strange phenolic off flavors.

After more research, I can say with close to 100 percent certainty that I had an infection from a wild brett strain in my buckets. They have been thrown out. Everything else bleach sanitized.

It's great news that you found a source of a problem and eliminated it. Good work!