(FIGURE 1) Vendome copper pot still at Wilderness Trail Distillery.
obvious solution is to buy a bigger mill, but that’s not always possible or feasible. Another solution is to grind ahead of cooking. That way the milled grains are ready for addition and your cook time is less dependent on your milling speed. That is pretty much common sense, but I promise we will get more technical below.
COOKING AND MASHING
(FIGURE 2) Vendome continuous beer column at Wilderness Trail Distillery.
How quickly you can turn over a cooker is directly correlated with production speed, because you can’t start a new cook until your last cook is finished and the tank has been emptied. Big time killers in cooking/mashing are several fold. Distilleries cook mash in many different ways. Several will add the grains to water that is either ambient or 150 F and then heat it all up, sometimes to temperatures above boiling. Keeping track of cook temperatures is important for batch-to-batch consistency and energy savings. Depending on your method of heating (steam, electric, wood or other fire, etc.) this can take a long time. Again, we are trying to turn the cooker as quickly as possible. If you start with cold water it takes longer to heat (and more energy), so starting with warm/hot water saves time and energy, especially if you can get hot water by conserving heat from another area of production. We installed water coils in our stillage tank (which is normally around 200 F) so that we can generate hot water (>150 F) for filling the cooker. This saves a lot of time and also helps us recover some of the heat energy from the stillage. Rather than add any grains at this point, we steam the water and increase to our target
temperature of 192 F. At this point we cut the heat and no more active heating is applied during our cook process (another energy saving step). We know from experience that corn starch gelatinizes well at temperatures of between 175190 F, so we know we don’t have to maintain our starting cook temperature of nearly 190 F (and we certainly don’t need to go above that). When we add the corn the additional mass lowers the temperature of the mash naturally. However, afterwards we are still in the optimum temperature range for excellent starch conversion. There is a certain residence time required for starch conversion in cook, but keep in mind that every minute allotted for cooking is another minute added to turn over that batch. Choosing the shortest residence time that will get the job done and not leave behind unconverted starch is key to quick batch turnover. This will somewhat depend on the particular grain recipe, so use your best judgement and experiment to determine the best cook time for any particular mash bill. After corn, the next grain we add is wheat or rye depending on the mash bill, so cooling the mash to 145-150 F is another step that adds to our cook time. The time it takes to cool a cooker is directly related to your maximum temperature (starting from boiling compared to being at 170 F after the corn rest, for example), the capacity of your chilling system, and other factors. For example, there is a big difference in using incoming water (well or city water) versus chilled water. This will vary based on location, but here in Danville, KY our incoming water ranges from the low 40s F in the winter to over 70 F in the summer. To cool quickly you have to have WWW.ARTISANSPIRITMAG.COM
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