Page 1 of 1

When would you need to increase alkalinity?

PostPosted: Fri Jul 24, 2015 11:30
by Mark
I know they're not going to be 100% but I just used a mash chemistry calculator. I entered my water profile including Alkalinity from a recent salifert kit. It's really low - 12 ppm.

Then I entered the grain bill for a recipe I'm looking at. It's Jamils Black Forest Stout (M.O 6.3kg, Crystal 40 284g, Crystal 80 284g, Black 340g and Choc 227g)

This says my alkalinity will be 5.48... well within the accepted range. I assumed with my alkalinity being so low, and the beer being a high abv stout, that I would need to add something to the water to stop the pH going too low. In fact I'm nowhere near it.

Out of interest, on this site you can instead enter the SRM and then it asks % Roasted Colour. How would you work out this. I assume in the example above the black and the choc are the only roasted malts and they probably give most of the colour, but how would you put a number to it?

Thanks :)

Re: When would you need to increase alkalinity?

PostPosted: Fri Jul 24, 2015 13:26
by AltonAnt
If it is a problem you could steep your roasted malts as they are not required to be mashed.

Re: When would you need to increase alkalinity?

PostPosted: Fri Jul 24, 2015 13:36
by Mark
It's not a problem, but that's my question really. When on earth would it be a problem when a water supply with almost no alkalinity is fine for brewing a stout with an 8kg or so grain bill?

Re: When would you need to increase alkalinity?

PostPosted: Fri Jul 24, 2015 13:52
by AltonAnt
I don't expect the calculation to be correct TBH.
What calc were you using?

Re: When would you need to increase alkalinity?

PostPosted: Fri Jul 24, 2015 15:05
by Eric
Getting the right mash pH is not the be all and end all that we are often told it is. If the mash pH is too high or too low it signifies that you should expect problems while getting it right doesn't signify there will be no problems with the final beer.

Calculators predicting mash pH are not reliable over the full range of grists and liquors, although there may be specific conditions when they get very close.

It is possible that a mash for stout using your liquor will fall into the acceptable zone for pH because your water also has very little calcium to lower pH. The shortage of calcium will influence the finished product in both quality and flavour. If you wanted a rich stout like those of years gone rather than the modern day well advertised, heavily filtered to remove the problems of low calcium, chilled to near freezing to minimise harshness, then you would need significantly more calcium and chloride in the liquor. That would cause pH to be too low, becoming unstable when amongst other things the result would less predictable. That condition does not arise when alkalinity is higher.

Re: When would you need to increase alkalinity?

PostPosted: Sun Jul 26, 2015 15:07
by NickW
I use smart price water for a stout. Which is low in calcium. I then add calcium chloride to the kettle