FIGURE 4 a) Glass column fitted with copper and stainless steel mesh to evaluate the chemical role of copper in the profile of botanical oil components. To ensure equivalent levels of reflux, copper was substituted with stainless steel of equivalent area and mesh size, and b) details of a bespoke glass vessel that allows different metals to be inserted to mimic a basket. In our case the work is currently restricted to stainless steel and copper. HUGHES & HARTZOG
during gin distillation. The research so far is in its early stages. but inspection of over 100 individual botanical components has not led us to observe any systematic influence of the presence of copper on the profile of oil components in the final spirit. The complexity of gin is clear, and the nuances that affect its flavor profile are subtle. In our studies, we are trying to understand the sensitivity of the gin botanical profile in terms of production variables, specifically material of still construction, how the botanicals are presented and the degree of reflux afforded by still design. Until now we conclude that, in decreasing order of importance, gin composition is affected by: maceration vs entrainment
copper vs steel for still construction Nevertheless we do need to broaden the range of botanicals used and to extend the range of reflux and still configuration options to more firmly establish our initial observations. Acknowledgement: We would like to acknowledge our colleague Professor Elizabeth Tomasino for her substantial input into the development of a gin analysis method and making her instrumentation available.
Paul Hughes, Ph.D. is assistant professor of food science and technology at Oregon State University in Corvallis, OR. For more information visit www.oregonstate.edu or call (541) 737-4595.
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