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General Category => General Homebrew Discussion => Topic started by: James on October 11, 2018, 03:42:22 PM

Title: Trying to determine source of off flavor
Post by: James on October 11, 2018, 03:42:22 PM
So several, but not all, of last few batches have come out with a similar off flavor, and I am trying to determine what caused it. The flavor is to me a green sort of grass flavor.

From what I have found online the closest thing I can find that would cause this is improperly stored hops. I keep my hops vacuum sealed and in a freezer when not being used. I have read that they should stay good for a fairly long time. The hops I used were in the freezer ranging from around a year for one batch to a month or so in another. So I am not sure that is the issue.

I had another thought, but can't seem to find any information on rather it would cause such an issue. I did a yeast starter for all the batches, and just let it sit on the stir plate at room temperature, and it being Texas summer that temp may have hit the high 80s during some days. Could that cause an off flavor like this?

I'm planning a brew day for next Weekend, and going to rebrew one of the recipes, but stick the stir plate in my fermentation fridge, and see if that fixes it, but was wondering if anyone had an insight about off flavors from too high of starter temps.

Also if anyone has any other suggestions as to what would cause it I appreciate it.
Title: Re: Trying to determine source of off flavor
Post by: hopfenundmalz on October 11, 2018, 04:06:40 PM
If there is a club in your area, see if you can get an experienced brewer to taste it and give recommendations.
Title: Re: Trying to determine source of off flavor
Post by: Robert on October 11, 2018, 04:45:23 PM
What are the recipes for the "grassy" batches?  That might help us identify a likely cause.
Title: Re: Trying to determine source of off flavor
Post by: Richard on October 11, 2018, 09:34:49 PM
Do you pitch the whole starter? If you cold crash it for a couple of days, decant the liquid and only pitch the slurry then any effects of high temperature fermentation should be minimized.
Title: Re: Trying to determine source of off flavor
Post by: James on October 12, 2018, 03:27:22 PM
hopfenundmalz,

I am planning on bringing a few samples to my clubs meeting this weekend for just that reason, but thought I would throw it out here as well.

Robert,
One was a Marzen, Jamil's recipe from Brewing Classic Styles, one was the Can You Brew It Arrogant Bastard Clone, and one was a Celis Pale Bock clone from Austin Homebrew. In the mix as well I brewed my Pale Ale recipe, with no problems, and my Hefeweizen with no problem.

Richard,
I do pitch the whole starter. I thought about decanting, but I thought part of the idea of a starter was to pitch active yeast and thought cold crashing would negate that, but I guess I could crash, decant and then maybe add a bit of wort in on the brew day to get it active again. 
Title: Re: Trying to determine source of off flavor
Post by: denny on October 12, 2018, 04:24:04 PM
hopfenundmalz,

I am planning on bringing a few samples to my clubs meeting this weekend for just that reason, but thought I would throw it out here as well.

Robert,
One was a Marzen, Jamil's recipe from Brewing Classic Styles, one was the Can You Brew It Arrogant Bastard Clone, and one was a Celis Pale Bock clone from Austin Homebrew. In the mix as well I brewed my Pale Ale recipe, with no problems, and my Hefeweizen with no problem.

Richard,
I do pitch the whole starter. I thought about decanting, but I thought part of the idea of a starter was to pitch active yeast and thought cold crashing would negate that, but I guess I could crash, decant and then maybe add a bit of wort in on the brew day to get it active again.

While crashing your starter is worth a try, I haven't found any problems from pitching the whole thing.  How big a starter did you do?
Title: Re: Trying to determine source of off flavor
Post by: klickitat jim on October 13, 2018, 01:28:28 AM
hopfenundmalz,

I am planning on bringing a few samples to my clubs meeting this weekend for just that reason, but thought I would throw it out here as well.

Robert,
One was a Marzen, Jamil's recipe from Brewing Classic Styles, one was the Can You Brew It Arrogant Bastard Clone, and one was a Celis Pale Bock clone from Austin Homebrew. In the mix as well I brewed my Pale Ale recipe, with no problems, and my Hefeweizen with no problem.

Richard,
I do pitch the whole starter. I thought about decanting, but I thought part of the idea of a starter was to pitch active yeast and thought cold crashing would negate that, but I guess I could crash, decant and then maybe add a bit of wort in on the brew day to get it active again.
Pitching a whole starter... if you let it completely run its course, exposed to oxygen or air, then its oxidized and the yeast are done so there's no value to keeping the oxidized wort. If the starter has not run its complete course and the yeast are active and in suspension, its probably not terribly oxidized, and since the wort is full of active yeast in suspension, there is value to keeping/pitching the whole thing.

I wish we could have two separate terms for the two different methods, then we could know what each other is talking about. I make my starters the morning of brew day and pitch them that evening. The whole thing. It would be foolish to treat my starters the way a person would if they were simply using their starters to multiply yeast cells by allowing them to complete their life cycle and drop out of suspension. Conversely, why would they want to dump flavorless oxidized wort into their beer?

In short, we call both methods a starter, but both do not have the same purpose or the same results
Title: Re: Trying to determine source of off flavor
Post by: Richard on October 13, 2018, 01:32:13 AM
Pitching a large starter that was fermented at high temperature could cause some off flavors, but probably not grassy ones. That does sound more like something from the hops, or stale grain.
Title: Re: Trying to determine source of off flavor
Post by: Robert on October 13, 2018, 12:26:34 PM
hopfenundmalz,

I am planning on bringing a few samples to my clubs meeting this weekend for just that reason, but thought I would throw it out here as well.

Robert,
One was a Marzen, Jamil's recipe from Brewing Classic Styles, one was the Can You Brew It Arrogant Bastard Clone, and one was a Celis Pale Bock clone from Austin Homebrew. In the mix as well I brewed my Pale Ale recipe, with no problems, and my Hefeweizen with no problem.

Richard,
I do pitch the whole starter. I thought about decanting, but I thought part of the idea of a starter was to pitch active yeast and thought cold crashing would negate that, but I guess I could crash, decant and then maybe add a bit of wort in on the brew day to get it active again.
Pitching a whole starter... if you let it completely run its course, exposed to oxygen or air, then its oxidized and the yeast are done so there's no value to keeping the oxidized wort. If the starter has not run its complete course and the yeast are active and in suspension, its probably not terribly oxidized, and since the wort is full of active yeast in suspension, there is value to keeping/pitching the whole thing.

I wish we could have two separate terms for the two different methods, then we could know what each other is talking about.
I make my starters the morning of brew day and pitch them that evening. The whole thing. It would be foolish to treat my starters the way a person would if they were simply using their starters to multiply yeast cells by allowing them to complete their life cycle and drop out of suspension. Conversely, why would they want to dump flavorless oxidized wort into their beer?

In short, we call both methods a starter, but both do not have the same purpose or the same results
Jim, you already solved this elsewhere.  An active one like you do is a "starter," because you're just getting the yeast awake and going.  One that's completed and decanted is "propagation,"  because you're growing up a new supply of cells, no longer active, which need to start up again when pitched.  (What I do, and what I call it.)  All that's left is to popularize the use of these preexisting, perfectly sensible terms. Start a movement.  Or propagate one, either way.
Title: Re: Trying to determine source of off flavor
Post by: Richard on October 13, 2018, 04:44:07 PM
Jim, you already solved this elsewhere.  An active one like you do is a "starter," because you're just getting the yeast awake and going.  One that's completed and decanted is "propagation,"  because you're growing up a new supply of cells, no longer active, which need to start up again when pitched.  (What I do, and what I call it.)  All that's left is to popularize the use of these preexisting, perfectly sensible terms. Start a movement.  Or propagate one, either way.

Sourdough bread makers have starters, too, and it usually refers to the sleeping culture. You warm it up and feed it, wait until it doubles, make bread with half of it and put the rest in the fridge. If someone looks in your fridge and asks you what that white goop is you say it is your sourdough starter.
Title: Re: Trying to determine source of off flavor
Post by: James on October 13, 2018, 05:39:17 PM
While crashing your starter is worth a try, I haven't found any problems from pitching the whole thing.  How big a starter did you do?

The Marzen was a 2 liter starter for a 10 gallon batch. The other 2 were 1 liter starters for 5 gallon batches.

I will usually get my starter going Wen. night for a Saturday brew. It stays on the stir plate until I'm ready to pitch.

I will try crashing and decanting on the next brew, and not change anything else.

Quote from: Richard
Pitching a large starter that was fermented at high temperature could cause some off flavors, but probably not grassy ones. That does sound more like something from the hops, or stale grain.

The grains I order fresh every batch from a homebrew store with good turn around, so I doubt that it's the grains. The hops are what I am fearing because I have a rather large stock of hops vacuum sealed and in my freezer, and would hate to have to throw them away. They have all smelled fine when I opened them, which from what I have read usually means they are still good.

Title: Re: Trying to determine source of off flavor
Post by: denny on October 13, 2018, 05:58:06 PM

While crashing your starter is worth a try, I haven't found any problems from pitching the whole thing.  How big a starter did you do?

The Marzen was a 2 liter starter for a 10 gallon batch. The other 2 were 1 liter starters for 5 gallon batches.

I will usually get my starter going Wen. night for a Saturday brew. It stays on the stir plate until I'm ready to pitch.

I will try crashing and decanting on the next brew, and not change anything else.

Quote from: Richard
Pitching a large starter that was fermented at high temperature could cause some off flavors, but probably not grassy ones. That does sound more like something from the hops, or stale grain.

The grains I order fresh every batch from a homebrew store with good turn around, so I doubt that it's the grains. The hops are what I am fearing because I have a rather large stock of hops vacuum sealed and in my freezer, and would hate to have to throw them away. They have all smelled fine when I opened them, which from what I have read usually means they are still good.

Didn't realize you were using a stir plate.  You should definitely decant, then.  I stopped using my stir plate a couple years ago because I found it wasn't necessary.
Title: Re: Trying to determine source of off flavor
Post by: Robert on October 13, 2018, 06:41:27 PM
Jim, you already solved this elsewhere.  An active one like you do is a "starter," because you're just getting the yeast awake and going.  One that's completed and decanted is "propagation,"  because you're growing up a new supply of cells, no longer active, which need to start up again when pitched.  (What I do, and what I call it.)  All that's left is to popularize the use of these preexisting, perfectly sensible terms. Start a movement.  Or propagate one, either way.

Sourdough bread makers have starters, too, and it usually refers to the sleeping culture. You warm it up and feed it, wait until it doubles, make bread with half of it and put the rest in the fridge. If someone looks in your fridge and asks you what that white goop is you say it is your sourdough starter.
Thanks for reminding me, I have to feed that goop in the fridge tonight!  Anyway,  cars have "starters" too, but we can't analogize everything called a "starter."  With bread, the goals are also distinct from the two brewing procedures in question,  pure propagation and pure activation.   Sourdough is both.  Some homebrewers actually  do something like this.  But this just shows how fuzzy the language we use is, and how useful it would be, as Jim said, to have a way of clearly understanding what we're all talking about, since what's ideal procedure for one is not for the other.
Title: Re: Trying to determine source of off flavor
Post by: denny on October 13, 2018, 06:51:35 PM
I don't think the language is all that fuzzy until we murk it up.  Starters have always referred to cell propagation.  so let's not change that.  Let's find another word for "the other thing".
Title: Re: Trying to determine source of off flavor
Post by: Robert on October 13, 2018, 07:12:21 PM
I don't think the language is all that fuzzy until we murk it up.  Starters have always referred to cell propagation.  so let's not change that.  Let's find another word for "the other thing".
"Rousing?"   It's been used that way before.
Title: Re: Trying to determine source of off flavor
Post by: RC on October 13, 2018, 07:55:37 PM
I'm skeptical it has anything to do with your starter. I, and others I know, have pitched hundreds of (propagation) starters, both decanted and not, and haven't had this flavor result.

My money is on the hops. Being plants, hops are full of chlorophylls and other not-so-great tasting chemicals, and the levels of these chemicals will vary from year to year, grower to grower, etc, just like resins and oils will. These chemicals will leach into the beer, just like the good stuff will. If they're at high levels in the hops to begin with, the grassiness could overwhelm the good stuff.

I've gotten grassy beers before, but it has been conclusively due to dry hopping. I'm guessing you didn't dry hop your grassy beers...did you do a late addition with them?
Title: Re: Trying to determine source of off flavor
Post by: klickitat jim on October 13, 2018, 11:31:19 PM
hopfenundmalz,

I am planning on bringing a few samples to my clubs meeting this weekend for just that reason, but thought I would throw it out here as well.

Robert,
One was a Marzen, Jamil's recipe from Brewing Classic Styles, one was the Can You Brew It Arrogant Bastard Clone, and one was a Celis Pale Bock clone from Austin Homebrew. In the mix as well I brewed my Pale Ale recipe, with no problems, and my Hefeweizen with no problem.

Richard,
I do pitch the whole starter. I thought about decanting, but I thought part of the idea of a starter was to pitch active yeast and thought cold crashing would negate that, but I guess I could crash, decant and then maybe add a bit of wort in on the brew day to get it active again.
Pitching a whole starter... if you let it completely run its course, exposed to oxygen or air, then its oxidized and the yeast are done so there's no value to keeping the oxidized wort. If the starter has not run its complete course and the yeast are active and in suspension, its probably not terribly oxidized, and since the wort is full of active yeast in suspension, there is value to keeping/pitching the whole thing.

I wish we could have two separate terms for the two different methods, then we could know what each other is talking about.
I make my starters the morning of brew day and pitch them that evening. The whole thing. It would be foolish to treat my starters the way a person would if they were simply using their starters to multiply yeast cells by allowing them to complete their life cycle and drop out of suspension. Conversely, why would they want to dump flavorless oxidized wort into their beer?

In short, we call both methods a starter, but both do not have the same purpose or the same results
Jim, you already solved this elsewhere.  An active one like you do is a "starter," because you're just getting the yeast awake and going.  One that's completed and decanted is "propagation,"  because you're growing up a new supply of cells, no longer active, which need to start up again when pitched.  (What I do, and what I call it.)  All that's left is to popularize the use of these preexisting, perfectly sensible terms. Start a movement.  Or propagate one, either way.
They may think it's a Movement, and that's what it is, the klickitat jim anti-massacre starter movement? And all you gotta do to join is to sing it the next time it comes around on the guitar

With feelin'

Title: Re: Trying to determine source of off flavor
Post by: jeffy on October 13, 2018, 11:34:58 PM
hopfenundmalz,

I am planning on bringing a few samples to my clubs meeting this weekend for just that reason, but thought I would throw it out here as well.

Robert,
One was a Marzen, Jamil's recipe from Brewing Classic Styles, one was the Can You Brew It Arrogant Bastard Clone, and one was a Celis Pale Bock clone from Austin Homebrew. In the mix as well I brewed my Pale Ale recipe, with no problems, and my Hefeweizen with no problem.

Richard,
I do pitch the whole starter. I thought about decanting, but I thought part of the idea of a starter was to pitch active yeast and thought cold crashing would negate that, but I guess I could crash, decant and then maybe add a bit of wort in on the brew day to get it active again.
Pitching a whole starter... if you let it completely run its course, exposed to oxygen or air, then its oxidized and the yeast are done so there's no value to keeping the oxidized wort. If the starter has not run its complete course and the yeast are active and in suspension, its probably not terribly oxidized, and since the wort is full of active yeast in suspension, there is value to keeping/pitching the whole thing.

I wish we could have two separate terms for the two different methods, then we could know what each other is talking about.
I make my starters the morning of brew day and pitch them that evening. The whole thing. It would be foolish to treat my starters the way a person would if they were simply using their starters to multiply yeast cells by allowing them to complete their life cycle and drop out of suspension. Conversely, why would they want to dump flavorless oxidized wort into their beer?

In short, we call both methods a starter, but both do not have the same purpose or the same results
Jim, you already solved this elsewhere.  An active one like you do is a "starter," because you're just getting the yeast awake and going.  One that's completed and decanted is "propagation,"  because you're growing up a new supply of cells, no longer active, which need to start up again when pitched.  (What I do, and what I call it.)  All that's left is to popularize the use of these preexisting, perfectly sensible terms. Start a movement.  Or propagate one, either way.
They may think it's a Movement, and that's what it is, the klickitat jim anti-massacre starter movement? And all you gotta do to join is to sing it the next time it comes around on the guitar

With feelin'
You can get anything you want
At Klickitat’s restaurant
Title: Re: Trying to determine source of off flavor
Post by: klickitat jim on October 13, 2018, 11:41:31 PM
Lol, I thought only Denny would get that one
Title: Re: Trying to determine source of off flavor
Post by: tumarkin on October 14, 2018, 12:33:14 AM
There I was sitting on the Group W bench with all the starter and propagators, talking about hops, and yeast and all kinds of other mean nasty stuff.
Title: Re: Trying to determine source of off flavor
Post by: mainebrewer on October 14, 2018, 09:57:17 AM
Lol, I thought only Denny would get that one


There are a few of us old guys out here who remember this stuff.  8)   
Title: Re: Trying to determine source of off flavor
Post by: denny on October 14, 2018, 02:56:52 PM
Lol, I thought only Denny would get that one

Oh, I did, but Jeff is no cultural nebbish!
Title: Re: Trying to determine source of off flavor
Post by: denny on October 14, 2018, 02:57:29 PM
There I was sitting on the Group W bench with all the starter and propagators, talking about hops, and yeast and all kinds of other mean nasty stuff.

MARK!
Title: Re: Trying to determine source of off flavor
Post by: James on October 14, 2018, 07:47:26 PM
Quote from: denny
Didn't realize you were using a stir plate.  You should definitely decant, then.  I stopped using my stir plate a couple years ago because I found it wasn't necessary.

Definitely going to decant the next batch. Might have to split a 10 gal batch and use stir plate on 5 and not on the other and see if I notice a difference.

Quote from: RC
I'm skeptical it has anything to do with your starter. I, and others I know, have pitched hundreds of (propagation) starters, both decanted and not, and haven't had this flavor result.

My money is on the hops. Being plants, hops are full of chlorophylls and other not-so-great tasting chemicals, and the levels of these chemicals will vary from year to year, grower to grower, etc, just like resins and oils will. These chemicals will leach into the beer, just like the good stuff will. If they're at high levels in the hops to begin with, the grassiness could overwhelm the good stuff.

I've gotten grassy beers before, but it has been conclusively due to dry hopping. I'm guessing you didn't dry hop your grassy beers...did you do a late addition with them?

Yeah I thought the yeast was a stretch, but was trying to figure out what the common denominator was between the good batches and the bad. The hops seem like the most likely culprit. Need to do the same recipe and use fresh hops in one and my stored hops in the other. I've been storing hops this way and not had any issues for about 3 years now, and the age of the hops in the beers varied greatly with one of them only being a few month old, and one being close to 2 years old.

The only other time I had this was when I first started using my DIY electric Keggel and some hops stuck on the heating element, I built a hop spider to keep them from touching the element and haven't had any problem in over a year.

Thankfully none of them have been so bad that I wanted to dump them, and the flavor does seem to age out, albeit slowly.
Title: Re: Trying to determine source of off flavor
Post by: James on November 01, 2018, 06:04:27 PM
SO I brewed a small one gallon batch using some extract and bittering with an once of the hops used in the worst of the bunch, and while not a great beer, it was just a test, there is none of the off flavor.

Thinking back on it I remembered that I did try something new for awhile where I would leave my immersion chiller in for the entire boil to avoid having to remove the hop spider to add it at the last 15. The 1 batch in the midst of the 4 that I didn't do this because I do all late hop additions is the one that turned out fine Could this cause off flavors?

Other thought was maybe something was in the air, I don't have an oxygen setup yet, but that would be odd in that I had one batch in the midst of the 4 that did just fine.

I've done three batches now, not including the test one, and have had no off flavors.

It's kinda driving me crazy because I can't figure out where it came from.
Title: Re: Trying to determine source of off flavor
Post by: Jeff Zesch on November 08, 2018, 08:03:15 AM
Lol, I thought only Denny would get that one


There are a few of us old guys out here who remember this stuff.  8)


What we need are "27 8 x 10 glossy photographs with circles and arrows and a paragraph on the back of each one"  to really determine the problem
Title: Re: Trying to determine source of off flavor
Post by: Monty Helmcamp on November 09, 2018, 03:49:40 PM
SO I brewed a small one gallon batch using some extract and bittering with an once of the hops used in the worst of the bunch, and while not a great beer, it was just a test, there is none of the off flavor.

Thinking back on it I remembered that I did try something new for awhile where I would leave my immersion chiller in for the entire boil to avoid having to remove the hop spider to add it at the last 15. The 1 batch in the midst of the 4 that I didn't do this because I do all late hop additions is the one that turned out fine Could this cause off flavors?

Other thought was maybe something was in the air, I don't have an oxygen setup yet, but that would be odd in that I had one batch in the midst of the 4 that did just fine.

I've done three batches now, not including the test one, and have had no off flavors.

It's kinda driving me crazy because I can't figure out where it came from.

In the books How to Brew (Palmer) and Brewing Beer: Problems (Hendricks) the most common cause of grassy flavor is poor ingredient storage. Like malt or hops picking up moisture or being stored poorly. Also, you could get a grassy flavor from adding hops at knockout or whirlpooling due to hop polyphenols no being neutralized by the boil. If that's something you were doing.

Two really good resource books, imho.
Title: Re: Trying to determine source of off flavor
Post by: James on November 11, 2018, 06:49:20 PM
SO I brewed a small one gallon batch using some extract and bittering with an once of the hops used in the worst of the bunch, and while not a great beer, it was just a test, there is none of the off flavor.

Thinking back on it I remembered that I did try something new for awhile where I would leave my immersion chiller in for the entire boil to avoid having to remove the hop spider to add it at the last 15. The 1 batch in the midst of the 4 that I didn't do this because I do all late hop additions is the one that turned out fine Could this cause off flavors?

Other thought was maybe something was in the air, I don't have an oxygen setup yet, but that would be odd in that I had one batch in the midst of the 4 that did just fine.

I've done three batches now, not including the test one, and have had no off flavors.

It's kinda driving me crazy because I can't figure out where it came from.

In the books How to Brew (Palmer) and Brewing Beer: Problems (Hendricks) the most common cause of grassy flavor is poor ingredient storage. Like malt or hops picking up moisture or being stored poorly. Also, you could get a grassy flavor from adding hops at knockout or whirlpooling due to hop polyphenols no being neutralized by the boil. If that's something you were doing.

Two really good resource books, imho.

Read Palmer's book many times, never read the Hendricks one I will have to check it out. The malts were all new from a homebrew store that has good turn around and used with in a week of getting them. The hops were all vacuum sealed in a freezer, and I've done a few beers since using them and didn't get it. The hops were all added during boil on the three beers that had it, with the latest being a 10 minute addition.

I gave all of my equipment a very intense cleaning and have not had it since. I am wondering if it was perhaps something on the heating elements that I didn't see, but was there. I just replaced them with stainless steel ones when after doing the deep cleaning I got rust flaking off my cheap ones. Still not sure why one in the middle had no off flavors at all and was the hoppiest beer in the 4. But I have now done 3 batches on it and had no problems. Brewed a Scotch Ale yesterday so we will see how that comes out.
Title: Re: Trying to determine source of off flavor
Post by: 6thstreet on December 05, 2018, 08:34:28 PM
I grow quite a few of my own hops and have had this issue a few times. I vacuum seal my hops, keep them frozen, out of the light, etc. and still have had those issues. I really feel that the earlier comment on chlorophyll hit the nail on the head.

I believe that my harvesting skills, or lack of, has played a part in my issues. I typically grow too many bines, don't trim back well enough and save damn near everything that has grown. I believe this gives less AA's, myrcene etc and just as much if not more chlorophyll type flavors due to more hop material used (less fully matured hops per capita). Less bang for the buck on the oils and more green material in my kettle, essentially. My Cascades have been notorious for this but I have seen it in Centennials and Northern Brewer's as well.

I grew a lot less hops this last season and took much better care of them. This has not been an issue now using this years hops and the same recipes. Just made an Imperial Red with last years hops (significant dry hopping as well) and it's back! That's all the evidence I need. I would expect this to be less of an issue with commercial hops but it could still be contributing.