If you've read my blog recently, you know that my goal at the start of this year was to brew up a killer saison. I went through my first iteration a few months ago and it turned out tasty, but I still feel I can definitely improve on it. Now, I'm a huge proponent of paying attention to your ion levels/mash pH and I believe you can't brew great beer without great water. So I felt the next step I should take to improve this beer was to delve deeper into water chemistry. (Beware: Some serious geeking out below)
We've all read about the recommended range that each ion has. For reference here are the levels pulled from Water: A comprehensive Guide for Brewers (Palmer and Kaminski)
Chloride: 0-100 ppm
Sulfate: 0-250 ppm
Calcium: 50-150 ppm
Sodium: 0-50 ppm
Bicarbonate sort of aka alkalinity: <100 ppm
Following these ranges you see descriptors of what higher levels taste like
Chloride: "Levels greater than 250 ppm....tastes pasty or salty...> 300 ppm can have negative effects on clarification, body and colloidal stability"
Sulfate: "At concentrations over 400 ppm however, the resulting bitterness can become astringent and unpleasant"
Calcium: "essentially flavor neutral, but it can reduce the somewhat sour flavor perception of magnesium...minerally"
Sodium: "can contribute a salty taste at concentrations of 150 to 200ppm...may taste harsh and sour in excess, especially when > 250 ppm"
Bicarbonate: I can't find definitive info about levels, but this is closely tied into alkalinity which is really what water chemistry is about.
So I read all this and thought, well, now I need to test this. I can read all about what tastes like what at what concentration, but until I really taste it, I can't know how it will turn out. To me, this is all theoretical and I needed a practical example.
Commence the experiment which is outlined here but for those who want a summary: rebrew my saison from before with a slight tweak in grain bill, ferment out with Wyeast 3711, then split it 3 ways and dose each split with CaSO4, NaHCO3 or CaCl2, respectively, at bottling. Most importantly, dose it high enough that it's in excess so we can test these threshold numbers.
Those numbers to be exact:
Post boil into the fermenter (after adding salts to adjust my mash pH)
Ca 80 | Mg 1 | Na 47 | Cl 55 | SO4 95 | HCO3 134
First gallon 1.5 g CaSO4 added (final pH into bottles 3.9)
Ca 197 | Mg 1 | Na 47 | Cl 55 | SO4 375 | HCO3 134
Second gallon 1.6 g NaHCO3 added (final pH into bottles 4.4)
Ca 80 | Mg 1 | Na 162 | Cl 55 | SO4 95 | HCO3 441
Third gallon 1.1 g CaCl2 added (final pH into bottles 3.9)
Ca 185 | Mg 1 | Na 47 | Cl 241 | SO4 95 | HCO3 134
2 weeks in the bottles and it was time for a taste test. I poured the beers into glasses marked on the bottom, had my SO mix them up, then we tasted them.
My tasting notes below are somewhat sparse, but that's for a reason. The beers were, overall, extremely similar. I was expecting a huge difference in these beers. I'm pushing the upper limits of ion concentrations in beer from what I've read and I expected a similar taste disparity. What I found was that my SO, who drinks a ton of beer, couldn't taste a difference. After tasting through all three beers for 30 minutes, I found that there were subtle differences, but nothing huge or groundbreaking. I would have been happy with any of these beers. This biggest difference is the slightly elevated bitterness note in beer 3, coming from what I assume to be the elevated sulfate.
Beer 1 (CaCl2)
Taste is slightly sour, a slight harshness on the back end. Somewhat lingering in the finish.
Beer 2 (NaHCO3)
Fruity up front. Slightly dry and chalky in the finish.
Beer 3 (CaSO4)
Fell off on back end. Rounded. More bitter than others.
I know the sample size of this experiment = 1 and it's tough to draw meaningful conclusions from one experiment with no replication but the most significant thing I take away from this is to not be afraid of your water chemistry, especially if you end up high or low. I'm going to go ahead and say can't taste the difference in a beer that has 40 ppm Ca versus a beer that has 50 ppm Ca, for example, and you might not even be able to taste the difference in a wider range either.
In the future I need to push the upper boundaries even further to find a meaningful taste threshold for these ions. I might also blend some of these beers to see if elevated levels of everything does anything to the overall taste. Many more thoughts going on in my head with regards to water chemistry and the like.