(or More Water Gobbledy-Gook)
You learn something new everyday, so they say, and the more I scratch the surface of this craft of brewing the more I realise that even though it has a strong basis in science (after all none of it would work without the science), bringing all the science together to brew the perfect beer is more of an art form than you would suspect!
I've already discussed the importance of profiling the water by reducing carbonate and therefore alkalinity of the brewing liquor. After adding CRS to reduce the carbonate I was a little worried about the high levels of chlorides and sulphates remaining in my water.
Someone pointed out to me that actually the levels left in my water are quite small compared to the sulphate level in Burtonized water (which have sulphate levels at around 800ppm).
What is much more important to the flavour of the beer at the end of the process though is the ratio of Sulphates to Chlorides. A higher ratio of Sulphate will result in the hop flavour and bitterness being accentuated, whereas a higher ratio of chloride will result in the malt characteristics being more accentuated in the final product.
One of the reasons that Burton breweries were famous for quite strong and hoppy beers was the high sulphate levels in the source water compared to the chlorides, the strength of the beer being upped to increase the maltiness and body of the beer.
I probably have about 1 1/2 times the amount of sulphate to chloride in my water so it will accentuate the hoppiness a little. Initial samples of my latest brew show a very clean and crisp hop bitterness and flavour to the brew without being overly astringent.
In addition, the target mash Ph is not only defined by the water but also the profile of grain being used. Obviously darker malts will lower the Ph in the mash as they are more acidic than pale malts.
Calcium Sulphate (Gypsum) and Calcium Chloride flakes will both have the effect of lowers the Ph as well but one will increase the sulphate and the other the chloride allowing fine tuning of the flavour profile.
So to brew the perfect beer there are a large number of scientific conditions that need to come together at the same time (Alkalinity, Mash Ph, mineral content, mash temperature, hot break, cold break). As each recipe may call for tweaks to the process then, although backed up by the science, the brewer is practicing an art form that requires good knowledge of the ingredients and processes in order to bring it all together at the right time.
So brewing is a science and an art form. I continue to learn more every day, and enjoy the product of that learning even more.