What am I doing wrong with my dark beers?

[PADave]

I need some help. I mostly brew IPAs, probably 90% of my brewing, and they come out really well. I've been doing full volume BIAB, using bottled spring water, because our well water sucks. I don't check any pH, or add any salts. I've got my system down to where I can hit the OG numbers within a point or two, and the FG is usually close to what I'm shooting for.

Where I'm running into problems is with my dark beers. Every one that I've brewed has had a high FG. My latest was Yoppers Oatmeal Stout recipie, and my FG was really high 1.026. I've done a brown ale two times. Both times the OG was high, but I bottled anyway, and both times I got gushers. None of these beers were high OG, usually around 1.054ish.

I know it's not the yeast, because it's the same yeast I use for my IPA's (US05 or S04). Are the dark grains messing with my mash pH? Is my full volume mash messing things up for dark brews? Am I getting lucky with my water and it works for IPAs, but isn't good for dark brews? Should I start using distilled or RO water and adding salts? Just looking for a place to start.

 

[day_trippr]

Assuming you aren't battling infections, gushing bottles implies either over-priming or beer that wasn't ready to be bottled (ie: FG was still falling).
Do you do a couple of successive hydro checks to look for stable FG before packaging?

Cheers!

 

[PADave]

Assuming you aren't battling infections, gushing bottles implies either over-priming or beer that wasn't ready to be bottled (ie: FG was still falling).
Do you do a couple of successive hydro checks to look for stable FG before packaging?

Cheers!

It's not infections, because the gushers only happened to me twice, with the same recipe (over 30 other brews were fine). Not over priming either. The gushers took a couple months to develop. No, I don't take multiple hydro readings. I take one at bottling time, which is after 3 weeks in the fermenter. Like I said above, my IPAs come out really good, never had a problem. But every dark beer I try is finishing at 1.020 or higher. Something with the dark malts is causing this.

 

[Lefou]

Are the dark grains skewing your mash pH?
Yes. To offset this, you'll need to balance your mash water to offset the acidity the darker grains will add. Adjust your water's alkalinity by adding a measure of bicarbonate or dissolved calcium carbonate in seltzer water. Chris Colby has a great guide on his blog "beerandwinejournal.com" about adjusting water with salts and how light and dark SRM beers are different. I use his stuff as a good reference.
Besides, I'm sure one or more water gurus might spot your post and give you a lot better advice. I'm still forking around with lighter beers for now. My first adventure to The Dark Side was a pretty foul and acrid bitter Dunkel that went down the drain.

 

[GoeHaarden]

Are the dark grains skewing your mash pH?
Yes. To offset this, you'll need to balance your mash water to offset the acidity the darker grains will add. Adjust your water's alkalinity by adding a measure of bicarbonate

^^^^^THIS

No expert here, but I think this is your issue. Highly roasted malts will drop your mash pH like it went 30 seconds against Mike Tyson. Since you're using bottled water, there really isn't a way to know the mineral content. I'd switch to distilled water (since you're buying it anyways), and then use one of the water addition calculators to adjust your water from scratch. I'd use baking soda to bring your pH back up, as CaCO3 is insoluble in water.

 

[Cyclman]

I reserve and add my dark grains in the last 15 mins of my mash, saves hassles.

 

[cactusgarrett]

No, I don't take multiple hydro readings. I take one at bottling time, which is after 3 weeks in the fermenter. Like I said above, my IPAs come out really good, never had a problem.

First thing is to not blindly trust that fermentation is done. For ANY batch. You may have simply gotten lucky with the other batches, but multiple grav readings should be taken before considering to bottle, especially if you go to bottle and you're reading 1.02X and you don't suspect the yeast.

Besides that, your mash chemistry is likely an issue, too, as others have suggested.

 

[tgolanos]

I reserve and add my dark grains in the last 15 mins of my mash, saves hassles.

The only dark beers I really make are Altbiers, but I do something similar; I mash my light grains while steeping my dark ones in a separate pot. Mix it all together at the start of the boil.

 

[soccerdad]

I'm adding a note here to be subscribed and follow. My water must be just the opposite. Dark beers need no adjustment and drop right into correct range. But I can screw up a lighter colored beer in a heartbeat if I add no salts or acid.

 

[65C]

We've high ph water here and I can't go wrong on the darks (I still adjust with lactic acid)

Can you post the recipe? my biggest problem is brewing IPAs, I can do pils and porters to a high standard but still not got a single IPA I'd serve to someone else

 

[PADave]

We've high ph water here and I can't go wrong on the darks (I still adjust with lactic acid)

Can you post the recipe? my biggest problem is brewing IPAs, I can do pils and porters to a high standard but still not got a single IPA I'd serve to someone else

These are a couple of the recipes that I have done. Did the brown ale twice, same results both times, and most recently Yooper's Oatmeal Stout.

https://www.homebrewtalk.com/showthread.php?t=494166

https://www.homebrewtalk.com/showthread.php?t=210376

I've been reading about water chemistry the past couple days. Still kinda doesn't make much sense, but I going to try using distilled water and adding salts for my next brew. Checked my additions on a couple different calculators and they both give the same results. So I going to go for it.