Off flavor that I can't figure out

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massination

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So I'm posting on here, because I cannot figure out the root cause of an off flavor in my last 4-5 batches. I've been describing it as a bitter/sour taste. And it doesnt go away with age. I thought maybe lacto infection, but all the beers have the same off-ness to it, and they're all very drinkable, but just have an ever persistent tang to them that I want gone and cant figure out.

I thought maybe it was my taste buds going wacky, but i recently had someone over and gave them no background info or warning and asked them to taste a recent batch and tell me if they detected anything off. They said it was really good beer, but it sorta tasted like it had some wine or white grape juice mixed in. So its not just me.

Now some details. Sorry for the longness of the details below, but i figured I'd try to answer all the questions you may ask....

I've been brewing AG BIAB, all lagers lately, full volume mash. Things like mexican lager, american lager, vienna lager. I've been using mostly dry lager yeast - S-189 but i did use some liquid yeast for the mexican. I've had my mill gap set around .030 or less, grinding it pretty fine since I dont have to worry about stuck sparge. For water, I use filtered water. I sent a sample off to be tested a while back, and have been using those results as a basis on how to adjust the water for salts for the style as well as PH adjustments, using the Bru'n Water spreadsheet. I chill with a copper immersion chiller outside. The pot lid mostly covering the wort while chilling. I put the chiller in when theres 15 minutes left in the boil in order to sanitize it. And then transfer directly into a sanitized glass carboy with a sanitized funnel. I dont usually completely fill the carboy with starsan, usually a couple quarts, and swish it around a bunch of times while I'm brewing. The carboy gets cleaned after fermentation with OxiClean, which really does a good job getting everything out. I ferment in a temperature controlled mini fridge at the recommended temp (around 55) for a couple weeks till done, then cold crash, and fine with gelatin in primary for a few days before I keg it. Most of the grain I have been using is a bag of pilsner that is over a year old, maybe as old as 2 years old....i just finished it off. But everything i read says grain that old should be fine if stored properly. I've had it in sealed buckets.

Now with all that said - does anything see a place in there where this off flavor could be coming in? One thing I was looking at was maybe its astringency from tannins. Perhaps my grind is too fine and it is grinding the husk up too much and bringing out those tannins. Though, from stuff I've seen online people say that is true and isnt true, with plenty accounts of people saying they grind real fine and have no issues, but with no real evidence that I've seen of people saying their beer was astringent because they ground fine. And seen where people say it can be astringent/tannins from sparging too hot. I dont sparge at all, and my mash temp stays pretty dang consistent. Like starting at 150 and ending at 148-149.

Another place is maybe the water report i sent off a couple years back is no longer valid for my water. I still use the same filter (have changed the elements since then). By the way, this is not a RO filter, its a 3-stage filter that gets all the chlorine out (confirmed) as well as flouride and some other stuff, but it does not take all the salts out. But according to the water profile report, the water I am starting with is pretty soft, so I think the filter is taking most of the stuff out. BUT, i dont test my PH. From everything I have read, the Bru'n Water spreadsheet is extremely accurate, so I have trusted that. I usually aim for around a 5.2-5.4 PH depending on the beer.

Another thought is maybe I have a lot of wild yeast outside and they're getting in during the chilling? I dont have a huge chiller, but i'd say i chill for maybe 30 min to get it down as low as I can (usually down to about 70 degrees) before I stop chilling and transfer to the carboy.

So I dont know, maybe next time I'll try grinding at .039ish gap on my mill and use RO water from the grocery store or something, and see what happens. But does anyone have any other ideas? I would think that the couple quarts of starsan swished around in the carboy a bunch of times should be good enough, but maybe filling it completely is somehow better?
 
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How are you determining a 55F fermentation? Is that reading the beer itself, or what the fridge is set to?

What's your pitching rate and oxygenation protocol?

Sounds like you've got excessive esters. 55 degree fridge meaning beer a few degrees warmer than that, plus underpitching (lagers need a LOT of yeast), and likely insufficient oxygen at pitching will lead to noticeably fruity lagers. Especially if you're pitching hot on top of it. You have to chill all the way to fermentation temps if not slightly below. I forget which strains but some like to throw grapey esters.
 
How are you determining a 55F fermentation? Is that reading the beer itself, or what the fridge is set to?

What's your pitching rate and oxygenation protocol?

Sounds like you've got excessive esters. 55 degree fridge meaning beer a few degrees warmer than that, plus underpitching (lagers need a LOT of yeast), and likely insufficient oxygen at pitching will lead to noticeably fruity lagers. Especially if you're pitching hot on top of it. You have to chill all the way to fermentation temps if not slightly below. I forget which strains but some like to throw grapey esters.

Thanks for the reply. I usually chill down to about 52 before I pitch. Then i pitch and let it rise to 53-54, and usually let it rise to 55ish towards the end of fermentation/activity, just to help speed it up a tad. As for temperature control, i use a brewpi, which has 2 probes, one for the ambient air in the fridge and one stuck to the side of the carboy (with insulating foam around it, taped to the side) to read the wort temp. I control the fridge based on the wort probe, not the ambient probe.

For the last few beers I pitched 2 packs of dry yeast. I dont do much for oxygenation, but i never really have, and its never really been a problem, and I've been doing lagers for several years. But who knows, maybe you're on to something. The act of dumping the wort into the carboy causes lots of splashing, but i know thats not as good as using an O2 stone or something. But the fermentations have taken off right away. This last one had good activity in 12-24 hours and a nice krausen in 24-48.
 
Bitter, sour, wine, and white grape juice are all very different flavors. Can you describe it any more precisely?

Can you post your recipe, starting water profile, volumes, mineral and acid additions too?
 
Disassemble & inspect your faucets. Look for corrosion on the shank barb too. I had a similar issue, and that was the cause.

I forgot to mention that I actually bypassed the faucets as a test. I hooked up a spare coupler with a bit of beverage line on it, and tasted the beer straight out of the keg, and it had the same off flavor in it.
 
Bitter, sour, wine, and white grape juice are all very different flavors. Can you describe it any more precisely?

Can you post your recipe, starting water profile, volumes, mineral and acid additions too?

Unfortunately I am not the best in pinpointing which off flavor it is. The guest I had in my house mentioned grape juice/wine. I thought it more to be sour/bitter, maybe more like a beer that was supposed to be sour, like a berliner weisse or something, not that i've had any of those lately. But if i had to blindly say without tasting one, maybe like 1/4 or so as sour as one of those, enough to bother me and want the taste gone, but not enough to dump my beer.

So dont hound me for my latest recipe. :) I've brewed maybe 30 batches, all of different styles, and this time i wanted to try a boring american lager with rice. Though I ran out of 2-row, so I used the pilsner i had left. The main thing I was testing in this batch was the use of rice, just for the fun of it. I also just used the yeast I had on hand, S-189.

7 lbs 5 oz 2-row (substituted pilsner)
2 lbs rice
2-packs dry yeast, S-189
.27 oz Magnum hops

Starting volume: 7.5 gallons
Volume after boil: Somewhere around 5.5 to 6

Shooting for:
1.047 OG
13 IBU

Existing filtered water profile (based on test results from lab)
Calcium: 12
Magnesium: 13
Sodium: 30
Sulfate: 33
Chloride: 22
Bicarbonate: 39

My adjustments in this beer:
.4 grams gypsum, which just brought calcium to 15 and sulfate to 40. So I really didnt adjust it much.

I was shooting for about a 5.3 pH, which Bru'n Water called for 70ml phosphoric acid (10% solution) to achieve, based on grain bill and water profile. I have lactic 88% and 10% phosphoric. I went with phosphoric this time, since lactic 88% would have taken about 7ml, which may have been at the threshold that some people say you can taste, but supposedly phosphoric you cannot. Again, trying whatever I could to avoid any off-flavors.
 
Unfortunately I am not the best in pinpointing which off flavor it is. The guest I had in my house mentioned grape juice/wine. I thought it more to be sour/bitter, maybe more like a beer that was supposed to be sour, like a berliner weisse or something, not that i've had any of those lately. But if i had to blindly say without tasting one, maybe like 1/4 or so as sour as one of those, enough to bother me and want the taste gone, but not enough to dump my beer.

So dont hound me for my latest recipe. :) I've brewed maybe 30 batches, all of different styles, and this time i wanted to try a boring american lager with rice. Though I ran out of 2-row, so I used the pilsner i had left. The main thing I was testing in this batch was the use of rice, just for the fun of it. I also just used the yeast I had on hand, S-189.

7 lbs 5 oz 2-row (substituted pilsner)
2 lbs rice
2-packs dry yeast, S-189
.27 oz Magnum hops

Starting volume: 7.5 gallons
Volume after boil: Somewhere around 5.5 to 6

Shooting for:
1.047 OG
13 IBU

Existing filtered water profile (based on test results from lab)
Calcium: 12
Magnesium: 13
Sodium: 30
Sulfate: 33
Chloride: 22
Bicarbonate: 39

My adjustments in this beer:
.4 grams gypsum, which just brought calcium to 15 and sulfate to 40. So I really didnt adjust it much.

I was shooting for about a 5.3 pH, which Bru'n Water called for 70ml phosphoric acid (10% solution) to achieve, based on grain bill and water profile. I have lactic 88% and 10% phosphoric. I went with phosphoric this time, since lactic 88% would have taken about 7ml, which may have been at the threshold that some people say you can taste, but supposedly phosphoric you cannot. Again, trying whatever I could to avoid any off-flavors.


Hmm that should all be fine. I just double checked everything in bru'n water and I got the same numbers you did.

Do you have the ability to measure the pH of the finished beer?

Would you describe the flavor like green apples at all?
 
Hmm that should all be fine. I just double checked everything in bru'n water and I got the same numbers you did.

Do you have the ability to measure the pH of the finished beer?

Would you describe the flavor like green apples at all?

Thanks for double checking in bru'n water on your end. At least we know that part should be fine. I dont have the ability to test PH...dont have any strips or a pH meter. But i suppose if my water is way off now from the report from a couple years back, perhaps my water profile is off. But i sorta doubt its so off to be the cause.

I dont think i'd describe it as green apples. Somewhere between the two descriptions of sour/bitter and grape juice/white wine. Maybe like if you took white grape juice and removed most of the sugar from it, so you end up with bitter/sour (less sweet), and then mixed some of that in with your beer
 
As a mostly lager brewer myself, I would try a batch with no acid added and maybe a recipe with a bit more roasted grain such as Vienna or Munich malt to get the pH down a bit more than just pilsner can do. I also would try and get the OG into 12.5-15 Plato range to build a bit more body in the finished beer. Most likely there's more to it than this but I hope that helps. Good luck.
 
Getting a cheaper pH meter off Amazon might not hurt either.
 
As a mostly lager brewer myself, I would try a batch with no acid added and maybe a recipe with a bit more roasted grain such as Vienna or Munich malt to get the pH down a bit more than just pilsner can do. I also would try and get the OG into 12.5-15 Plato range to build a bit more body in the finished beer. Most likely there's more to it than this but I hope that helps. Good luck.

The recipe posted was just my last batch. I've had this off flavor in my last 4-5 batches. One was 63% pilsner, 21% corn, 16% vienna. One was 76% pilsner, 24% vienna. Come to think of it, i did a pre-prohibition lager with 6row and 2row that it seems like did not have this off flavor. Could old malt cause this? I'd say its 2 years old, but was stored properly, or at least in sealed buckets. The pre-prohibition was mostly fresh 2/6 row, a small bit of corn, and 8 oz of carapils.
 
The recipe posted was just my last batch. I've had this off flavor in my last 4-5 batches. One was 63% pilsner, 21% corn, 16% vienna. One was 76% pilsner, 24% vienna. Come to think of it, i did a pre-prohibition lager with 6row and 2row that it seems like did not have this off flavor. Could old malt cause this? I'd say its 2 years old, but was stored properly, or at least in sealed buckets. The pre-prohibition was mostly fresh 2/6 row, a small bit of corn, and 8 oz of carapils.

Are you sure it's pilsner and not acidulated malt?

Eat some and see if it tastes tart
 
Are you sure it's pilsner and not acidulated malt?

Eat some and see if it tastes tart

Unfortunately (or maybe fortunately) its all gone now. I used up the last bit in my last batch. But I clearly remember inspecting the bag when I bought it. It was Best Malz German Pilsner malt. Unless the bag itself was mislabeled. I did taste some when i had it though, and dont recall anything off.
 
Were you using the same type of hop schedule in all these beers? I've had certain hops give me a sourish flavor.
 
Were you using the same type of hop schedule in all these beers? I've had certain hops give me a sourish flavor.

I've wondered that myself. So here's the hops I used in the last 3 beers where the of flavor has been the most noticeable, all lighter beers (kolsch, mexican, american). Also, i buy hops in bulk, so tend to use what i have, and the hops typically last me a while. These hops are probably ~2 years old, but vacuum sealed and stored in freezer.

kolsch - target 21 IBU
magnum (12.8% AA) .3 oz boil 60 minutes
stryian goldings (4.3%AA) .5 oz boil 15 minutes
stryian goldings (4.3%AA) .5 oz boil 15 minutes

mexican lager - target 20 IBU
Select Spalt (3.5% AA) 1.5 oz boil 60 min

american lager - target 13 IBU
magnum (12.8% AA) .27 oz boil 60 minutes
 
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