Diagnosing off-tastes and causes in failed juniper gose?

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Pappa_Bjorn

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My first ever non-kit beer went terribly wrong, and I can't figure out what caused the off tastes or what they're called.

Recipe for 3gal/11L single stage;
  • 0,45kg/1lb Acid malt
  • 0,9kg/2lb wheat extract
  • 0,3kg/10oz light extract
  • 10g/.4oz crystal @3%AAU 60m
  • 20g/.8oz juniper berries 20m
  • 2 orange peels 15m
  • 3tsp/18g/.6oz salt
  • 1pkg S-05
  • 6tsp/30ml/1fl.oz. 80% lactic acid when bottling
  • ~1.5g tablesugar, ~1.5g dextrose when bottling

OG: 1.0450
FG: 1.0115
IBUs: 5
(Fake IBUs pretending juniper bitter=hop bitter: ~12)
Final ABV: 4.4%
Fermented @ stable 18°C/64°F, 15d. Bottle conditioned 7+d @23°C/74°F.

Off flavours @+7d from bottling:
  1. Mild vinegar (NOT lactic acid)
  2. A quite strong smell/aftertaste like the lubricant oil used on subways, aircraft, old trains, some heavy machinery etc. Metallic, oily, artificial... I've tasted this in someone else's homebrew. What is it, and how do I avoid it???

Known errors:
  • Didn't crush acid malt. At all...
  • Bottled very sloppy with lots of air...
  • Used table sugar when bottling...
  • Batch was still active when bottling @+15d! Decided to bottle anyway since I needed the carboy. Didn't expect 18°C to give such markedly slower fermentation...
  • Fermented @18°C/64°F, but stored/bottle conditioned immediately @23°C/74°F...
What caused the aforementioned off tastes and how do I avoid these in the future?
 

Rob2010SS

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The first red flag I see is that you bottled with 6tsp of 80% lactic acid. This is a lot of acid. Not only that, but the fact that it looks like that's all you used to sour it, it has a very different taste from lactic acid produced by lactobacillus. This on top of 1lb of acid malt seems like the culprit to me.
 

bucketnative

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I agree. When I have purchased acid malt, the bin holding the grains often has a vinegary/acidic pungent odor. You used it at rate of 27% of your fermentables (that percentage uses the mass of the extracts). It is recommended for use only to adjust the pH of the mash water (typically at a rate of 1% to 10% according to the manufacturer). When used to "sour" the beer, it can give a very tangy flavor, that is more biting than sour (I recently used it at 5% of my latest beer in an attempt to give sourness, but got an acidic bite, instead - never again). Add the lactic acid on top... it's not ideal.

Perhaps next time try kettle souring with lactobacilli. There are multiple threads on that here. That will give you a natural tasting sour, rather than trying to fake it with short cuts. If it's worth doing, it's worth doing right.

From your "know errors"... using table sugar and a slightly elevated conditioning temperature are not errors. They are common practice for many bottlers here.

The other errors are just a matter of poor planning and execution. Cleaning those errors up are easy the next time. Better planning and a $5 plastic bucket fermenter can solve errors 1, 2, and 4.

It's a learning process. Learn and improve.
 

Rob2010SS

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+1 to what @bucketnative said. I was in a hurry when I posted my first response so wanted to elaborate on a few things.

Highly recommend using Bru'n Water to figure out your mash pH in the future. Just do a google search for it and download it for free. It's intimidating at first but just read the instructions and it's pretty simple to use. Just to give you an idea, my Gose that is fermenting now only used .16lb of acid malt. Total grain weight was just over 10 lbs and this was for a 5 gallon batch.

Like both of us have said, lactic acid from the bottle like that has a very weird taste to it. My blackberry peach sour that I have on tap currently, the lactobacillus crapped out at a pH of 3.4 and I wanted 3.2. I used lactic acid to drop it and it's definitely noticeable. It is not the same flavor achieved from lactobacillus.

You say you've tasted #2 off flavor is someone else's homebrew. What kind of beer was it that you tried? Do you know any details about the recipe?
 

RPh_Guy

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+1 for using Lactobacillus
http://sourbeerblog.com/lactobacillus-2-0-advanced-techniques-for-fast-souring-beer/

Back when I started homebrewing I kettle soured a wheat ale kit. It was definitely the best beer I ever made from a kit.

Although sours are great and fruit & spices can add interesting dimensions to beer, consider starting with MUCH more simple recipes until you are more comfortable with your process and adjusting or creating recipes on your own.

Cheers!
 
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Pappa_Bjorn

Pappa_Bjorn

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... you bottled with 6tsp of 80% lactic acid ...
... When I have purchased acid malt, the bin holding the grains often has a vinegary/acidic pungent odor. You used it at rate of 27% of your fermentables (that percentage uses the mass of the extracts). ... When used to "sour" the beer, it can give a very tangy flavor, that is more biting than sour ... it's not ideal. ...
It did get too sour for a mellow gose, but not ridiculously sour (it's tame compared to stuff like this or this). The acid malt, at 15% grain bill by my calc., was mistakenly not ground and thus probs contributed little to anything, and the lactic acid at bottling was 80%, not the usual 88%, and 'only' ~4ml (small tsp) per .5L/17oz. The off-taste was distinct, aromatic, and not related directly to lactic acid (I dissolved the lactic acid in water and tasted. No aroma/off-taste; just sour). It's possible the malt husks alone had enough pungency to contribute off-tastes, but I didn't detect this off-flavour in the wort suggesting it arose when fermenting/bottling.
+1 to what @bucketnative said. ... Highly recommend using Bru'n Water ... my Gose that is fermenting now only used .16lb of acid malt. Total grain weight was just over 10 lbs and this was for a 5 gallon batch. ... You say you've tasted #2 off flavor is someone else's homebrew. What kind of beer was it that you tried? Do you know any details about the recipe?
I'm looking at EZ Water Calculator, and when I get time I'll research how unbalanced water contributes to off-flavours in fermentation. Possibly, the acid malt dropped wort pH below where S-05 can handle 24C without excessive fusels?
The other 'beer' I've tasted with a similar off-taste was my buddy's underage attempt at acquiring alcohol. He used white sugar, lots of flaked unmalted/unmashed oats, poorly mashed barley malt, and unpasteurized lingon- and juniper berries pitched with baking yeast. The abomination was fermented without a proper air seal at a fluctuating 25C and capped at the last second in PETs for carbonation. It ...worked? Ish? But turned sour from lactobacillus in the lingonberries I guess. My guess is the off-taste is some kind of fusel since it smells like a mix of paint thinner and machine lubricant (if you went to a train museum, you'd go "Ah, THAT smell!").
... Did you just steep the acid malt in the boil kettle?
The recipe said mash the acid malt for [email protected]~68C in a small pot, so I did. ...Uncrushed.
+1 for using Lactobacillus ... consider starting with MUCH more simple recipes ...
The recipe was based on this. I probs won't mess with lactic again for a while, but maybe... I got a huge carboy collecting dust, and I recently drank this and got blown away by the fermentation. So I was thinking I could try to steal Alvinne's secret 'Morpheus Yeast' from a bottle, mimic their ale, and see what abomination is inhabiting the carboy come spring. Rumour has it 'Morpheus' isn't a brett but two abnormal S. Cerevisae and a lactic bacteria strain.

General follow-up:
I based my gose on this recipe but 'accidentally' seasoned with lactic 'to taste' at 4ml instead of 0.8ml per bottle (500% vs. recipe). Storing the bottles for a month markedly reduced the off-taste but didn't remove it. Still a 1/5 star beer - barely drinkable.

I've also made this elderflower mead and the part i fermented with S-05 has a slight trace of the same off-taste when completely fresh (haven't tasted the non-S-05 part). I've made an APA and a strong spruce ale with S-05 @same temp (23C/74F) that did not have the off-taste. The off-taste, which was not present in the wort or must, is reminiscent of paint-thinner or machine lubricant, which leads me to believe it's a fusel alcohol caused during fermentation. The fusel was very strong smelling in the hop bag used for lemon zest in my mead, and this gose also had lemon/orange zest. The mead had a low ferment pH due to added grape juice, the gose likewise due to a lot of added acid malt. My theory is that either a low pH and high temp causes S-05 to produce excess fusel alcohols, or the aromatic oils in citrus zest cause off-taste/fusels when fermenting at 23C w/ S-05, or both are culprits.

Conclusion:
Maybe don't use S-05 in sour worts at high temps, sour worts at all, and/or worts with even a trace of lot of citrus peel oils.

Edit:
After consulting google, I can only see people praising US-05 for fermenting out sours, including kettle sours and artificials. The plot thus thickens. Esp. since I fermented both the mead and gose first at ~18C and then at ~23C, which is well within the range of US-05 for both sours and unsours. Could a trace of citrus oil, the common denominator in the mead and gose, be the culprit? And if so, why would citrus peels be commonly used? Very strange.
 
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RPh_Guy

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Again, you're just beginning and so the complexity of the recipe IS the main problem.

We'd be happy to help set you up for success with your next attempt.

Lesson learned: Try to avoid "recipes" for beer on random cooking websites. They're often just a recipe for disaster.

Cheers
 

Rob2010SS

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Just a couple of comments on your previous post...

1. US-05 is perfectly capable of fermenting sour beers. I use it almost exclusively on my sours, minus the Gose I have going now.

2. You said you added the lactic acid at bottling at 500% more than the recipe called for. This will have a drastic effect on flavor.

3. The lactic acid not being crushed... This would give you the lactic acid that is on the grain without any of the fermentables, thus lowering your pH even more.

As @RPh_Guy said, in the future, post your recipes here and people will give you feedback here and help you tweak it to make sure you get what you want out of it.
 
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