# Drawing chalk to raise pH



## Bruer (10/4/16)

Hey all,

It's Sunday brew day. I'm making one of BrewDog's recipes - #101 cocoa psycho. I just realised it has a HUGE proportion of roasted grains for a 20L batch (130g dark crystal, 1.25kg black malt and 1.5kg roasted barley). It also has 6.9 kg pale, 1kg wheat malt and 500g smoked malt. I don't normally tinker with the mash pH - but I'm guessing that all this dark roasted goodness is going to affect the mash PH and potentially drop it too low.

My question is if it drops really low, can I bump it back up with some crushed drawing chalk (white obviously) or should I just let it go. Being Sunday and in Perth there are no HBS that are open within a 45 minute drive. That said, if I go do it then will, but just keen for a lazy brew day.

Cheers


----------



## manticle (10/4/16)

Chalk really doesn't dissolve well.

If you are super worried about pH, you can add the roast part way into the mash (I cold steep overnight and add 10 mins before mash out).

Adding drawing chalk doesn't sound like a great idea - it will probably contain impurities like clay and measuring the right dose of calcium, carbonate or predicting its effect on pH will be difficult.


----------



## verysupple (10/4/16)

Drawing chalk is usually actually made of gypsum these days. So if you did use it you would probably get the opposite effect to what you want.


----------



## rude (10/4/16)

Slaked lime is the go to bump you're ph up


----------



## MHB (10/4/16)

What VS said
If you can accurately measure your pH and it is lower than 5.1 then a bit of bicarb will get you out of trouble. Personally I doubt that it will be as low as you think, although dark malts lower pH the acidity is pretty week and there is a large buffering effect from all the pale malt and whatever carbonate is in your water.

Never been really impressed with Chalk as a brewing additive, but I have heard Shawn Sherlock one of the best brewers I know say he uses a fair amount in his stouts and he makes some of the best stouts I have ever tasted so what do I know...

Mark


----------



## Bruer (10/4/16)

Well just ran with the brew day, monitored the mash pH. MHB you were on the money. It only dropped to 5.1 which isn't too bad. Ended up getting 84% efficency. I normally BIAB, but ran a ghetto BIAB in an esky with a batch sparge from a bucket. All in all I'm pretty happy with the result in the end. Got it boiling now. Not much headspace in the keggle so will have to watch and spray down with a bit of water. Should be good.


----------

