So I’ve got something odd happening with my dark beers- anything with roasted malts. I can’t put my finger on the taste, but it’s consistent and similar in 3 batches of beer I’ve made recently. It’s a chocolate milk stout, Irish ale, and oatmeal stout. I’ve made many a batch in between (ales, lagers without roasted malts), before and after and no off tastes or undesirable characteristics- so I’m fairly confidant I’m not dealing with infection. Ph, mash temps, fermentation and sparge temps have all been as targeted. I’ve also done hot steep and cold steep of roasted malts to see if it changes anything, and it has not. The taste is hard for me to explain, other than it seems phenolic…but I’m not sure that’s it.
Anyway, if anyone is willing to give it whirl, I will mail samples out for anyone who thinks they can assist in my discovery of the culprit.
You don’t want me - I tend to have a very low threshold on a lot of phenols (I find clove all the time when others say it is not detectable) and evidently a very high one on DMS and Diacetyl (couldn’t find it for the life of me in a recent Helles that was called for it in a comp)…so I would not trust my palate, but which flavor profile are you experiencing that causes you to say phenol?
That alone may help…or not.
Could it be yeast based (selection or repitch issue)?
If this were in all your recent beers, I would suspect chlorine in water or possible infection, as these could cause phenols in beer. Your likely yeast choices for these beers would not likely produces a lot of phenols fermented cool. But since it seems confined to your dark beers, I wonder if the black roasted malts are giving you this impression. I find black patent and roasted barley to be slightly smokey in higher amounts. Also I target a mash pH of ~ 5.5 for these beers, because IMO the darker malts can come across as more acrid and harsh at lower pH. Just a thought.
Good comments. Ph has been 5.4-5.5. Yeast has been Yorkshire square, wlp 007, and wlp041. All ferment at 64-67. Yes gypsum is used- no more than 82ppm for 5 gal batch.no chlorine- I have well water and it goes through RO system for my beer.
My chocolate milk stout used cold steep of 8oz English dark crystal, 8 0z light choc malt, and 8 oz carafa 3 dehusked. Oat meal was hot steep 12oz choc malt, 3oz roasted barley, 3oz black malt. Irish red was hot steep 4 oz roasted barley. Irish has the least amount of this taste I’m tasting.
Not sure I would know what this is or not…but is gypsum astringency similar to puckering astringency you would get from tannins? If so there is no puckering characteristic at all.
I bet it’s the gypsum in combination with the dark grains. Try brewing the same recipe, but replace gypsum with CaCl2.
I’m not sure astringency was the right word choice in my first post, but it’s been my experience that I get a very harsh after taste in dark beers I’ve brewed with gypsum. I actually like it in a robust porter.
interesting hypothesis. ive thought about the brewing salts as a possible culprit. last year i was using well water until i had RO system installed. since RO, ive really had to use brewing salts to dial things in…and im wondering if it has had an impact on the roasted malt recipes.
The sulfate ions imparted from gypsum leave a harshness, especially in dark beers IME.
If you’re just adding gypsum for pH control, replace it with CaCl2. The calcium in gypsum is reacting with the malt phosphates to liberate H+ ions, which lower the mash pH. The CaCl2 will have the same effect, just target the same Ca ion concentration using whatever water chemistry software you use.
so im not using gypsum for PH control at all - just targeting a brew profile that has additions of CaCl2, CaSO4, NaHCO3, and bit of MgSO4. Perhaps I need to start using pickling lime and drop the gypsum levels so I can reach proper calcium levels without exceeding chloride levels.