RIS water

[brownni5]

Tomorrow a friend and I are undertaking a big (for us) project - a RIS that will eventually need to fill a 15- gallon rye barrel. There's a ton of grain, and a good portion of that is black/roast (we're scaling up a clone of Stone's Imperial Stout). I just plugged the numbers into Bru'n water, and to get the pH respectable, a lot of baking soda and pickling lime are needed, really bumping up the sodium numbers and the bicarbonate, while having essentially no sulfate or chloride (building up from RO water).

I understand very little about water, and when brewing mostly pale beers, I let Bru'n water take care of it for me. What options do I have to raise the pH for the mash without letting my water get out of control? I'm trying to avoid chalk - I've heard that isn't great for mash additions - is that incorrect?

Grist: 51 lbs pale
6.6 lbs Amber
4 lbs Black Patent
4 lbs Roast
2 lbs oats
17 gallons into the fermenter

I'm told his system can handle all this grain - I'm hopeful. The question remains - what to do about the water?

It would appear that by backing off the black stuff (a pound each) and increasing the base malt by a pound to recover some extract would fix a lot of problems. But the bicarbonate is still very high - is that a concern?

 

[mabrungard]

The bicarbonate is just the causation of the alkalinity needed to balance the grist's acidity. It is what it is. Chalk is a waste of time, so using lime and baking soda are your best bets for supplying the alkalinity.

I don't recommend leaving out sulfate and chloride entirely. You'll want some level of those ions to help flavor the beer. With the roughly 10% roast in that grist, I'd be lenient with the sulfate content. But it shouldn't be zero. Both roast grains and sulfate are 'drying' in a beer, so you don't necessarily want to over do it. But if this is going to be a high gravity beer that may have significant residual sweetness, then the sulfate could actually be welcome. It's dryness can help mask an overbearing sweetness and cloying.

 

[brownni5]

Very thorough and we'll explained - thank you!

 

[hottpeper13]

Also when using 100% RO water you need to make sure to add calcium for oxalate precipitation and yeast health, 50 ppms minimum. I use RO water because my alkalinaty is ~400 ppm. When I brew a dark beer I just dilute my house water with RO to get the 250 or so ppm's needed. Could you do the same? If I had to add salts to get there I would most likely opt for cold steeping the dark grains and adding at vorlof.

 

[isomerization]

I strongly recommend adding a good chunk of the dark grains after the majority of the mash is complete. This supposedly reduces some of the harsher roasty notes, but perhaps more importantly, allows greater control of the mash pH.

Also, I enjoy higher Na levels in my dark beers and would comfortably recommend up to 60-80 ppm.