An Ankoù
Landlord.
All the explanations of water alkalinity talk about calcium carbonate (equivalents) as buffering the pH of the water/malt mixture so that too much alkalinity can prevent the mash from achieving its optimum pH. We can correct this in one of three ways: treating the water with acid; diluting the water with low-mineral water; using malts which are more acidic- ie, dark malts or acidulated malt.
Let's look at this from the other way round. A given sample of mash water can only contain a fixed amount of CaCO3 (equivalent) and if enough base malt were added, then the buffering effect would ultimately be overcome. The limitation on this, of course, would be mash density- we can only add a certain amount of malt to a given volume of water before it's too thick to work. My question is this: is there an easy way of calculating how much base malt would be needed to achieve optimum pH in a given volume of untreated water of a certain alkalinity? For example, my tap water has 107 ppm of CaCO3. Is there any way other than by trial and error that I can calculate how many grams of malt per litre of pale ale malt I would need to add to overcome the buffering effect and achieve optimum pH. A complication would seem to be that the pH of the malt is not necessarily indicative of the pH of the mash. A quick bit of research shows that most base malts have a pH around 5.6 - 6 so the remaining drop 5.2-5.4 must come from enzymatic activity.
I'm fully aware that this doesn't take into account the effect of the sparge water on the boil pH. That's a question for another time and I'm already wondering whether the mash can buffer this to any useful extent.
Any thoughts out there?
Let's look at this from the other way round. A given sample of mash water can only contain a fixed amount of CaCO3 (equivalent) and if enough base malt were added, then the buffering effect would ultimately be overcome. The limitation on this, of course, would be mash density- we can only add a certain amount of malt to a given volume of water before it's too thick to work. My question is this: is there an easy way of calculating how much base malt would be needed to achieve optimum pH in a given volume of untreated water of a certain alkalinity? For example, my tap water has 107 ppm of CaCO3. Is there any way other than by trial and error that I can calculate how many grams of malt per litre of pale ale malt I would need to add to overcome the buffering effect and achieve optimum pH. A complication would seem to be that the pH of the malt is not necessarily indicative of the pH of the mash. A quick bit of research shows that most base malts have a pH around 5.6 - 6 so the remaining drop 5.2-5.4 must come from enzymatic activity.
I'm fully aware that this doesn't take into account the effect of the sparge water on the boil pH. That's a question for another time and I'm already wondering whether the mash can buffer this to any useful extent.
Any thoughts out there?
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