Further purification of food-grade alcohol to make a congener-free product

Abstract

Most alcoholic beverages contain small amounts of chemicals other than ethanol, the congeners. These are byproducts of the fermentation process of the substrate. Congeners are implicated in contributing to hangover (veisalgia) symptoms and it is therefore considered expedient to remove these substances. This research compared 12 established vodka brands with a new product by GC-MS-olfactometry. A new vodka produced in Iowa from corn was found to be the purest while another corn-based vodka and a potato-based vodka contained eight and 12 impurities each. Eight other commercially available vodkas contained 15-19 impurities and three vodkas showed more than 30 impurities. Neither the raw material nor the country of origin made a difference to the level of the impurities. However, the treatment process was of great importance in terms of reaching lower impurity levels. Multiple distillations and filtration did not seem to benefit the quality, nor did charcoal and activated carbon alone. However, one vodka based on a multiple distilled neutral grain spirit process from corn contained zero measurable volatile impurities. The particular treatment process involved ozonation, followed by granular activated carbon and a nano-noble-metal catalysis and adsorption.