Thanks to their high sugar content and strong flavor, apples have been a great base for spirits like cider, calvados and applejack for hundreds of years. But “many decisions about their processing are still subjectively determined.” When to stop distillation for the most flavorful liquor, for example, is open to question. But new research has identified the best conditions for making apple-based spirits with the most desirable qualities and taste.
Researchers with the American Chemical Society fermented apples into a mash, then distilled it in a German-style batch column. Heat concentrates the alcohol and “removes unpleasant fermentation byproducts, such as carboxylic acids that can impart unclean, rancid, cheesy and sweaty flavors.” The researcher’s mash was continuously monitored during heating, and the levels of the nine carboxylic acids measured.
Heating the mash too quickly yielded unwanted flavor compounds and a bland aroma. But raising the temperature of the cooling tower slightly produced a good fragrance intensity, and reduced carboxylic acid levels.
Read more (American Chemical Society)