RIS Water Profile + Strike Water Volume Questions

[John Flores]

Hey ya'll -

I'll be brewing my first Russian Imperial Stout sometime over the next couple of months. In working up my recipe, I noted that my overall PH is incredibly low even with my bicarbonate levels at an appropriate level. Here's where I'm at with my current water profile:
Ca: 90
Mg: 15
Na: 45
Cl: 75
SO4: 50
HCO: 250
Adjusted PH: 4.9

In reviewing past posts on this topic, I've noted that this is a common challenge when using dark malts. And I'm already familiar with using slaked lime and/or baking soda to increase bicarbonate. As others have mentioned, the challenge is raising ph without blowing out ones calcium or sodium levels.

So I guess what I'm looking for is a general overview on how others approach salt additions on brew day. My tentative plan is to generally stick with the above water profile and add a fixed amount of either slaked lime or baking soda during the mash to raise the ph level as needed (by fixed amount, I mean that I will pre-measure the additions so that I don't go way over Ca or Na levels). Does this approach generally jive with ya'll or am I just missing something here? I'd normally just jump in and get some hands on experience... but at 27lbs of grain I'm looking for a little advice

Lastly, I'm using Brewer's Friend as my recipe builder / water calculator. Their suggested strike water levels are 10.13 gallons for the mash and 0.58 gallons for sparging (targeting a 5.5 gallon batch with 27lbs of grain). I know I'm using a lot of grain here... but the mash water levels seem excessive while the remaining sparge water volume seems way too low (not enough water to raise the overall grain bed temp to 168°). I'm thinking that I'll pull back the mash water to 1.25 quarts per pound (roughly 8.45 gallons for mash and say 4 gallons for sparge). Anyhow... any thoughts here are also greatly appreciate!

 

[CascadesBrewer]

I am curious about the strategy of adding dark grains at the end of the mash or steeping them separately. I know this is the strategy that Gordon Strong recommended in his book instead of messing with raising the mash pH.

I brewed a RIS back in Jan before I had my pH meter and before I started with water chemistry. I assumed the mash pH was fairly low, but i just plugged it into Bru'n Water and that predicted a pH around 5.5. I had a Porter that I measured around 5.0, and I have not figured out my strategy when I try that recipe again. I screwed up my mash temp, so it is hard to say what impact the mash pH had on the final beer.

 

[John Flores]

I am curious about the strategy of adding dark grains at the end of the mash or steeping them separately. I know this is the strategy that Gordon Strong recommended in his book instead of messing with raising the mash pH.

I brewed a RIS back in Jan before I had my pH meter and before I started with water chemistry. I assumed the mash pH was fairly low, but i just plugged it into Bru'n Water and that predicted a pH around 5.5. I had a Porter that I measured around 5.0, and I have not figured out my strategy when I try that recipe again. I screwed up my mash temp, so it is hard to say what impact the mash pH had on the final beer.

Yeah good point... I've heard that some folks add most of their dark grains in during the last 20 minutes of the mash (they keep something like 10% of the dark grains in with the base malt and add later). This is something I may have to try... curious if this has worked out well for other folks.

I may run the numbers through Bru'n or something else just for a sanity check lol. Thanks for the thoughts!

 

[CascadesBrewer]

I'm thinking that I'll pull back the mash water to 1.25 quarts per pound (roughly 8.45 gallons for mash and say 4 gallons for sparge). Anyhow... any thoughts here are also greatly appreciate!

Also, this seems pretty reasonable and a 1.25 ratio is pretty standard. The 8.45 and 4 gal split should work well.

 

[Silver_Is_Money]

I can't possibly imagine starting out with 250 ppm bicarbonate (205 ppm alkalinity) mash water and winding up with a mash pH as low as 4.9. You might hit pH 4.9 in the mash if there is zero alkalinity present in the mash water in conjunction with a seriously judicious amount of deep roasted and/or caramel malts present within in the grist, but there does not seem to be any path to pH 4.9 with that initial high level of alkalinity.

 

[John Flores]

I can't possibly imagine starting out with 250 ppm bicarbonate (205 ppm alkalinity) mash water and winding up with a mash pH as low as 4.9. You might hit pH 4.9 in the mash if there is zero alkalinity present in the mash water in conjunction with a seriously judicious amount of deep roasted and/or caramel malts present within in the grist, but there does not seem to be any path to pH 4.9 with that initial high level of alkalinity.

Agreed, the 250ppm bicarbonate should do it. I actually went ahead and plugged the info into Bru'n Water and got an estimated PH of 5.56 using the same additions, grain bill, etc. I'm thinking that Brewer's Friend is off on this one. Thanks for the sanity check!

 

[Silver_Is_Money]

You are most likely entering something incorrectly in Brewer's Friend.

 

[John Flores]

You are most likely entering something incorrectly in Brewer's Friend.

Yeah it's certainly possible, though I've double checked everything and even rewrote the recipe. It would appear that BF and Bru'n calculate bicarbonate differently (slaked lime drops the bicarbonate level in BF whereas pickled lime increases it in Bru'n).

 

[Silver_Is_Money]

Technically there is no bicarbonate species present within Ca(OH)2 [which goes by names including slaked lime, pickling lime, and calcium hydroxide].

Bicarbonate is HCO3-

Hydroxide is OH-

Both species can however be equated to alkalinity.