Inconsistent problem (smell and flavor) with beers.

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Smithy

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So I have this flavor show up in my beers inconsistently. In 25 brews, this has happened 4 times. The first 2 times it showed up in the same beer recipe. Made me believe that it was the ingredients that I was using just didn't work well together. I brewed something completely different at a later date (Other brewing in between) and it showed up again!

Recently it showed up in my "house beer". I always have this beer on hand and was my first successful recipe. Two weeks ago I brewed my house beer and then I brewed my pumpkin spice beer. All in the same day. Pumpkin spice is perfect, the house beer (brewed first) has this strange smell and flavor. First time this has shown up in my house beer.

I use pellet hops. My house beer uses Matueka hops. Very citrusy like limes or grapefruit but gentle to drink. Its a hop that is seldom used by brewers (at least from my brew store where I buy them. Hopunion brand). 3 of these beers had this very hop added in conjunction with another hop. House beer is only this hop. The fourth beer used cluster hops. So the fourth beer removes that it could be this hop (Matueka).

The flavor is difficult to describe. I would say bitterly sour. Tastes the same as it smells. Like what you would think a bad grapefruit would taste like. One brewer thought it was "band aid". Read up on that one and I don't think so. I personally believe it to be old hops but I have never first hand experienced what old hops would do. One reason I say this because it's a seldom used hop (except for the one beer hop that was not Matueka). How long have they been in the store I buy from? The house beer that I recently brewed, I used hops that had been sitting in my refrigerator for at least 4 weeks. Not too much more time than that. Bag was never opened. No idea how long it had been in the store before that.

Question is, does a place exist that you can send in a sample of your beer and they can tell you what the potential compound is that is adding this flavor and smell and that doesn't cost a ton?

My processes are consistent as well as my equipment is always sanitary. Empirical opinions, thoughts and discussions would be greatly appreciated!

Thanks in advance.

Lee...
 
Go to your homebrew store and buy a bag of those hops, open it up and if it has a cheesy smell then the hops are old and bad. You will know right away when they aren't right.
 
Cheesy, old hops will not really give you a 'bitterly sour' flavor and aroma. Dirty feet, yes. But sour, no.

Assumptions I'm making here: by Matueka you mean Motueka - unless I am missing a new variety of hops. Also, you say "had been sitting in my refrigerator"... you should store hops in the freezer, not the fridge. The colder, the better!

If you take the ingredients out of the equation, the next step is to look at process faults. Do these batches share any of the same equipment that the other batches do not? I mean, like a transfer hose, a plastic secondary, a carboy cap even?

To be honest, "bitterly sour" sounds like an infection, so I'm trying to help from that aspect.
 
I have one bag of "Motueka" (Yep, spelled it wrong) and I opened it and I believe it smells pretty normal so maybe that isn't old.

My refrigerator is pretty cold and my brew store puts them in a fridge so I have been doing the same. Maybe I should change my ways with that.

All beers go through the same equipment with the exception of carboys and blow off caps. That is pretty random and the only pieces that not all beer touch, but I have had four beers fermenting at a time several times without a problem. It rears its ugly head when primary is done. Never any hint of it otherwise. This strange aroma and flavor is VERY random! Driving me nuts.

I think infection too but I absolutely do not know. I will be putting this beer in front of Julius Hummer (Gravity Brewing Brewmaster and Son of Co-Founder of Boulder Beer, one of the nations first micro-breweries) after GABF is over here in town, see if he knows what it is. He has been around and masters in beer! Was hoping someone might have experienced something similar or knows of a scientific approach I could send it to.

There is not one thing in my process that I can question where this may be coming from. I am very good at repetition processes and cleanliness. But you all know how that goes!... At least I can distill it. That's what I do when this happens but what a pain.
 
If he can identify the flavor more accurately, then that will be a huge help in trying to troubleshoot from a couple of states away. Let us know what he says! :mug:
 
"Bitterly sour" makes me wonder about water, particularly a higher magnesium level (although some people like that "enhancement" of the hops and add epsom salts on purpose to that end). I find that a higher magnesium level has this dry bitter, almost sour but not quite, taste to it that I find that I do not like.

Is it possible that the water supply changed in some of those batches, or that some epsom salts were added?
 
I don't dry hop at all currently or in the past with these batches that became a problem.

It is possible that my municipality water changed slightly, however the water quality report (Sampled in 2012) does not state magnesium levels. They do have the following statement in the report:

The state requires us to monitor for certain substances less often than once per year because the concentrations of these substances do not change frequently. In these cases, the most recent
sample data are included, along with the year in which the sample was collected.


Leads me to assume the levels are low or non-existent. Total assumption. Could be wrong. I do run my water through a carbon filter. Nothing more. The municipality states that my water is alkaline (PH is 8 average).

This last two batches run on the same day and water taken from the same source (Storage after carbon filter less than 4 hours old) only one batch has this issue.

The smell is what I would guess from an old grapefruit. Very sour. Taste I would describe as being the same. Very sour grapefruit. It's not strong like disgusting, but it is most certainly there. Best I can describe it.

I would send a sample to anyone if they are interested!... Some people have curiosity and want to try. LOL...
 
I would send a sample to anyone if they are interested!... Some people have curiosity and want to try.

Not gonna lie, I'm half tempted.

But you wanna talk crazy? I led an off-flavor class last night with 13 other crazy people who sat around drinking intentionally bad beer. Now that's a bit off!
 
One thing to note is that the source could be several things. For instance, the taste is described as "bitterly sour". The bitter portion could be astringency caused by mash pH issues and/or temperature issues. The sour portion really sounds like contamination.
 
Good point on the possibility of multiple contributors.

This is kinda lengthy but I’ve got the writing bug tonight.

Infection ...
I’d wonder whether a lactic acid issue wouldn’t express more cleanly. Not like rotten grapefruit, but just sour.
On the other hand, a combination of contributors? ... the hops, an infection, other faults?

In the future you might keep track of your pH and try to determine a baseline between batches and take multiple samples at specific times. Lactobacillus will lower the pH of the mash by creating lactic acid.
Further, I’m not a brewer, but ... did you mash at the same temps for the same amount of time between all batches? Did the mash have exposure to any fresh grain (or equipment involved with fresh grain) following the mash?
In any case I’d think lactobacillus should not survive the hot mash.

L. casei and L. brevis are common lactobacillus culprits.
Here’s a silly thought. L. casei is found in the human mouth. Are you siphoning anything using your mouth to start the flow? ... just a wild-assed thought.
L. brevis is even more common ... and one that resists the antimicrobial effects of hops. Brevis is the “rampant” lactobacillus of brewing history.
Not to put too sharp a point on it but both of those lactobacilli can be introduced by one’s hands if certain sanitation is not followed in the lavatory ... all that “employees must wash hands” stuff. I suppose in the case of brewing ... that would also necessarily mean an inadvertent introduction after the hot mash.

Both lactobacilli can be reasonably identified if you have access to a microscope. For what it’s worth you could check for Brett at the same time ... its not that I’m suspecting brett ... but anytime someone actually uses the description "band-aid" (as you mentioned in your original post) I’m thinking brett. Brett wouldn’t survive the heat either.
As well I can’t imagine where you’d get brettanomyces from. Have any fresh fruit or grapes hanging around in your brewing operations? ... get a used wine barrel into the building recently? ...

Acetobacter is another ... it's aerobic ... so oxidation sources would be a contributor. Maybe vinegary plus the natural expression of the hops you used could combine to produce the sharp, sour, grapefruit effect? Likely not. I’d think the vinegar character would be pretty obvious. Probably can disregard the acetobacter.

The lactic and aceto issues aside, in theory there could be other contributors.

Particularly if your beer does not show a pH drop from a lactobacillus infection, another fault such as this could be in the running.

Beermaking and winemaking are kinda first cousins and are more similar than sometimes given credit for.

There are chemicals called thiols (a type of mercaptan) that become “expressed” by certain yeasts and result in the final character of a wine ... and some of them specifically create that grapefruit effect like you found in your beer.
This action is specific to the yeast, which is responsible for converting the thiol precursors to the flavor-active-form of the thiol ... and is specific to the mash/must having the precursors which may or may not be converted.

Sulfur related compounds are at the heart of many of these “reduction defects” converting thiols/mercaptans. And sulfur production in significant part is a product of Hydrogen Sulfide production. Hydrogen sulfide production is a product of yeast health, nutrition, temperature and oxygen. I am not a brewer, but for beer I’d suspect you can rule out nutrition. This leaves yeast, yeast stress, temperature and oxygen.

Temperature I suspect you monitor closely already (?).
A lack of adequate oxygen depending on the yeast can definitely affect the production of precursor sulfur compounds ... unhappy yeast.

Pushing the limits in the Original Gravity? ... again, unhappy yeast ... one has to be careful with certain strains with the OG.

Did you get the yeasts from the exact same package or bag? It could be a difference in the yeast charge you pitched.

Did you rehydrate your yeast first? ... if so, how closely do you control the temperature of the rehydration water. It takes only a few degrees to significantly kill a good portion of the colony and leave you with a stressed charge of yeast.

Vintners are always suspecting unhappy yeast.
However my best *single* guess would be the lactobacillus infection as I noted above.

I kinda like the multiple contributor effect too as mentioned at the top of this post.

Anyhow ... sanitation, especially hands ... yeast happiness and/or change your yeast ... avoid sulfur compounds (i.e. H2S) especially by lowering ferment temps and insuring adequate oxygenation during ferment.

Hope some of this helps.
 
We have a chili fest in the neighborhood so I am really busy with that today. Tomorrow I will follow up with details and let Jacob Marley's thoughts sink in as that is a lot to ponder. I will also post ingredients and processes. Thanks all for your help!
 
Infection ... I’d wonder whether a lactic acid issue wouldn’t express more cleanly. Not like rotten grapefruit, but just sour.
On the other hand, a combination of contributors? ... the hops, an infection, other faults?

I will take this slow. In reference to the above quote, yes I believe you are correct that a cleaner description would be just sour. One would believe that a "rotten grapefruit" would taste just disgusting. This "sour" isn't disgusting however it's unpleasant. It is something you experience on the back and sides (back sides) of your tongue on the finish.

Now Motueka hops are very citrusy. So citrusy that at first when you taste this sour you believe that it is coming from the hops. Then it just keeps delivering stronger and you know it isn't correct. One batch that this happened to I used cluster hops and it was the same sour. Mash temps are always around 152 F with this and other beers. My temp consistency is + or - .5 degrees. Mash times are 1 hour. OG mostly stand between 1.050 and 1.060. Never higher. Always oxygenate my wort before yeast pitch and ferment temps are 66 to 71 F.

Will expand more on this later...
 
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