Hello all-I've been having some recent issues with S05 which mirror an earlier issue I was seeing with S04 a couple years ago. The thought back then was that I was fermenting too hot and I've now gone through 3 batches which seem to have the same off-flavors. I've done both Pale and Maris Otter base malts (no Pilsner) and an assortment of hops and other malt profiles, but all have been on the light end of the spectrum. The off-flavor I've noticed is hard to pin down, but it's roughly a slightly metallic, flat, almost stale flavor which smells about as much as it tastes. If I let it off-gas for a while it'll dissipate slightly but won't get fully better. The only consistency this time is S05, slightly high to properly high temperatures, and my equipment/process. I accidentally fermented at 30C (86F) because I didn't notice my basement was so hot, but then did a Maris Otter/Citra SMaSH ale at 24C (75F) and a 6% IPA at 23C (73F) and while the way over-temp batch was slightly stronger, they all have this flavor/smell to some degree. As I said before I had this issue with S04 a while ago and everyone seems to have thought it was because 24C was a bit too high for it, but I've done loads of batches (albeit slightly fuller-bodied ales) with S05 and never had an issue. Does anyone have an idea as to what is causing this, what this off-flavor might be better called, and how to avoid this in future? Thanks in advance!
Off-flavors with US05
- Thread starter rmeskill
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Yeast is exothermic, meaning it produces heat during fermentation. The actual temp of a batch may be 5-10 degrees higher than ambient temperature, which means if you're at 75 degrees ambient, your wort is likely between 80 and 85--which is too hot.
I like to do ales from about 64-67, but I'm controlling temp in a ferm chamber that's the actual temp.
You can moderate the temp by using a swamp cooler; place the fermenter in a pan of water, drape a t-shirt over the fermenter and allow it to dangle in the water. The water will wick up into the t-shirt and evaporate, cooling the fermenter. You can increase the cooling effect by putting ice cubes under the shirt at the top so as they melt they saturate the t-shirt.
You can also use a fan to blow over the area increasing evaporation.
I like to do ales from about 64-67, but I'm controlling temp in a ferm chamber that's the actual temp.
You can moderate the temp by using a swamp cooler; place the fermenter in a pan of water, drape a t-shirt over the fermenter and allow it to dangle in the water. The water will wick up into the t-shirt and evaporate, cooling the fermenter. You can increase the cooling effect by putting ice cubes under the shirt at the top so as they melt they saturate the t-shirt.
You can also use a fan to blow over the area increasing evaporation.
The measured temps are from a crystal thermometer on the fermenting vessel. Not a perfect system, but at least close enough for me to know roughly what the fermentation temp is. I've checked with a spot thermometer, too-I think my 23-24C numbers are accurate, which is why I'm confused why I get similar off-flavors at 23C/73F and 30C/86F...
thehaze
Well-Known Member
US-05 as per Fermentis: https://fermentis.com/wp-content/uploads/2018/08/SafAle-US-05.pdf
It states between 64-82F, which in Celsius is 18-28C. That's a pretty wide temperature range, for an yeast which everybody uses, but only fermented really, really cold, but not that cold, as it will throw peach esters. It's weird and funny at the same time.
I can only speak from experience with the yeast, and especially at higher temperatures, just as you do. I have not experienced the flavours you mention above. I have fermented at high temperatures both IPAs with 10-15 oz hops added and other styles, like Red/Ambers, Pale Ales, Black IPAs and Porters, and none suffered from any off-flavours.
US-05 is really quite clean at higher temperatures.
I would look somewhere else.
According to "How to Brew"
Metallic
Metallic flavors are usually caused by unprotected metals dissolving into the wort but can also be caused by the hydrolysis of lipids in poorly stored malts. Iron and aluminum can cause metallic flavors leaching into the wort during the boil. The small amount could be considered to be nutritional if it weren't for the bad taste. Nicks and cracks ceramic coated steel pots are a common cause as are high iron levels in well water. Stainless steel pots will not contribute any metallic flavors. Aluminum pots usually won't cause metallic flavors unless the brewing water is alkaline with a pH level greater than 9. Shiny new aluminum pots will sometimes turn black when boiling water due to chlorine and carbonates in the water.
The protective (grayish) oxides of aluminum can be enhanced by heating the clean pot in a dry oven at 250°F for about 6 hours.
It states that stainless steel won't give off these flavors, so I'm really not sure what the problem might be.
Threads to go through:
https://www.homebrewtalk.com/forum/threads/metallic-taste.63393/
https://www.homebrewersassociation.org/forum/index.php?topic=28681.0
https://aussiehomebrewer.com/threads/metallic-taste-in-beer.32585/
https://learn.kegerator.com/off-flavors-in-beer/
https://discussions.probrewer.com/showthread.php?15573-Mettalic-taste
It states between 64-82F, which in Celsius is 18-28C. That's a pretty wide temperature range, for an yeast which everybody uses, but only fermented really, really cold, but not that cold, as it will throw peach esters. It's weird and funny at the same time.
I can only speak from experience with the yeast, and especially at higher temperatures, just as you do. I have not experienced the flavours you mention above. I have fermented at high temperatures both IPAs with 10-15 oz hops added and other styles, like Red/Ambers, Pale Ales, Black IPAs and Porters, and none suffered from any off-flavours.
US-05 is really quite clean at higher temperatures.
I would look somewhere else.
According to "How to Brew"
Metallic
Metallic flavors are usually caused by unprotected metals dissolving into the wort but can also be caused by the hydrolysis of lipids in poorly stored malts. Iron and aluminum can cause metallic flavors leaching into the wort during the boil. The small amount could be considered to be nutritional if it weren't for the bad taste. Nicks and cracks ceramic coated steel pots are a common cause as are high iron levels in well water. Stainless steel pots will not contribute any metallic flavors. Aluminum pots usually won't cause metallic flavors unless the brewing water is alkaline with a pH level greater than 9. Shiny new aluminum pots will sometimes turn black when boiling water due to chlorine and carbonates in the water.
The protective (grayish) oxides of aluminum can be enhanced by heating the clean pot in a dry oven at 250°F for about 6 hours.
It states that stainless steel won't give off these flavors, so I'm really not sure what the problem might be.
Threads to go through:
https://www.homebrewtalk.com/forum/threads/metallic-taste.63393/
https://www.homebrewersassociation.org/forum/index.php?topic=28681.0
https://aussiehomebrewer.com/threads/metallic-taste-in-beer.32585/
https://learn.kegerator.com/off-flavors-in-beer/
https://discussions.probrewer.com/showthread.php?15573-Mettalic-taste
Yeah, I didn't see these issues with S05 before, even at higher (admittedly not 30C/86F, but relatively high) temps, and given this is roughly the same flavor I got from S04 when everyone thought it was high temps I'm thinking it's unrelated. That leaves me with my equipment which is as follows:
Stainless steel pots for the boil and strike water
30L plastic tub (bought from MLHBS specifically for brewing) for mashing/sparging/lautering
Steel filter on plastic feet with 3 (unfortunately rusting) screws holding the feet in
Plastic stirrer
Plastic/glass thermometer
Copper chiller
For sterilization I always (but only) use one-step oxidizer sanitizer after a thorough wash.
The only thing I can think of at this point is it might be a sanitation issue, but I also brew a lot of sours and have never had an unintended souring, so I'm also hesitant to say it's that.
My malts are probably not 'well kept'. I have dog food/cereal containers I put them in to keep bugs at bay and it's moderately warm in that closet (25C/75F) but not terribly moist or variable. But I've experienced this same flavor from fresh and old malt and multiple base malts-even got it on my SMaSH ale, so I'm inclined to think it's not a malt issue, either.
Thanks for the thoughts so far and I'm hoping it's not S05
Stainless steel pots for the boil and strike water
30L plastic tub (bought from MLHBS specifically for brewing) for mashing/sparging/lautering
Steel filter on plastic feet with 3 (unfortunately rusting) screws holding the feet in
Plastic stirrer
Plastic/glass thermometer
Copper chiller
For sterilization I always (but only) use one-step oxidizer sanitizer after a thorough wash.
The only thing I can think of at this point is it might be a sanitation issue, but I also brew a lot of sours and have never had an unintended souring, so I'm also hesitant to say it's that.
My malts are probably not 'well kept'. I have dog food/cereal containers I put them in to keep bugs at bay and it's moderately warm in that closet (25C/75F) but not terribly moist or variable. But I've experienced this same flavor from fresh and old malt and multiple base malts-even got it on my SMaSH ale, so I'm inclined to think it's not a malt issue, either.
Thanks for the thoughts so far and I'm hoping it's not S05
What about your water? Are you using RO/Distilled water or just from the tap?
I too got some unpleasant flavors - not sure I would say metallic but we all taste things differently- when fermenting at the upper range of US-05. As Mongoose33 has suggested, fermenting between 64-67 leaves a clean ester free beer. Toward the end of the ferment I raise the temp up to 68-70 as a diacetyl rest...probably not needed but doesn't hurt anything.
Your equipment seems in order and likely not contributing to the off flavors except maybe those rusty bolts...stainless replacements? - Try another brew with lower ferment temps and see if that helps.
Cheers!
Jako
Well-Known Member
it could be me but i no longer like us-05. it always taste off to me. i find myself spending more money on liquid yeast if i am going to try and save money its not on yeast.
if you get the chance you should try imperal Pub yeast. hands down the best yeast i have tried. it ferments super fast and drops out as clear as it gets.
if you get the chance you should try imperal Pub yeast. hands down the best yeast i have tried. it ferments super fast and drops out as clear as it gets.
I usually keep my chamber 62F-65F for US-05, so my beer's actual temp is going to be 67F-70F. If I want some of that peach flavor, I occasionally go as low as 58F. I would never run it at 82F. Perhaps if water chemistry, nutrition, and oxygen were all perfect, fermented under pressure, 82F might work but that requires a pro-level system.
If you have to run hotter, you should probably consider Kveik yeast. It can go up to 100F with no off flavors.
I would get my temperature problem under control first. Then if I still had off flavors, look at other problems with my process.
If you have to run hotter, you should probably consider Kveik yeast. It can go up to 100F with no off flavors.
I would get my temperature problem under control first. Then if I still had off flavors, look at other problems with my process.
I have found 05 to be a very off putting yeast for my tastes. Used it many times with similar off flavors and some different ones too. I say try to lower temp if you want/need to use this strain. Otherwise I would find another yeast to use. The kveik strains have produced great beers for me. especialy if you have limited temp control.
Jako
Well-Known Member
i am in the same boat. at my LHBS the guy would always say i save money and just go with 05 if i can. but once i started to used different yeast strains i had better results and it didn't taste like "homebrew" to me
