Page 34 - Craft of Whiskey Distilling

21 | AmErICAn DIstIllInG InstItutE
It is crucial for proper starch conversion to make sure the pH of your water is below 7. The optimal pH of a mash is 5.2. You can adjust the mash directly, but it is safer to adjust the dough in water in case you undershoot the pH which could compromise the mash.
To start, adjust the pH of the dough in water to 6 and then see what the pH of the mash is once doughed in. The two best agents to adjust pH are food grade phosphoric or lactic acid and are inexpensive. For those who do not want to use these naturally derived acids, you can use sauermalz which is an acidified malt made in Germany which brewers there use because they are not allowed to use acids to lower pH.
Another method to adjust pH would be to make a small “soured mash” by using lactic acid producing bacteria to ferment it. This technique is in essence how the aforementioned sauermalz is made. Attempting to use this technique would require a lot of experimenta- tion and may take a while to reach the desired result consistently. Another concern if this method is employed is that you run the risk of contaminating the pure yeast cultures used in regular fermentation or/and cross contamination of your plant.
You could also use the “set back” which is the wash that is left in your still after a run. The concentration process of distillation also concentrates the acidic nature of wash. But, this concentration can vary from time to time so developing a consistent dosing into a mash might prove difficult.
To test pH of mashes, paper test strips should not be used because of lack of range and the darkness of the mash makes readability difficult. It is best to get a lab grade pH meter from a scientific supply vendor. Make sure to get one that is automatically temperature compensated (ATC) and has a replaceable probe that is high temperature rated and will work properly in protein containing solutions. Do not use a pH meter designed for garden- ing. A pH meter requires calibration before each use. Purchase a meter that calibrates using two buffer solutions, one that is pH 4 and the other, pH 7.
MASHINg
The following example involves using a combi-tun which is the most common mash/ lautering system. In some plants, a mash mixer and a lauter tun are used. This type of sys- tem increases plant efficiency because while the first mash is being lautered, you can begin making another mash. In this style of system, the mash mixer is usually directly heated via low pressure steam. The downside is the additional expense of having two separate vessels and the additional space that is required.
The below example also utilizes a hot liquor tank for the preparation and introduction of water for both the dough in and sparging steps. This is preferred so that you can mix the water with the malt directly into the combi-tun. A grist hydrator is also used so that you can slowly mix the water with the malt to produce a uniformly hydrated and smooth mash. It is possible to dough in without one, but starch balling is inevitable if you simply dump