Other Distillation Compounds

STEM Challenge

Carver was interested in the chemicals that one might make from agricultural products. Alcohol production was a common use of the distillation process. The moonshiners knew how to do this well.  They mixed sugar and wheat, corn or barley grains and heated them with yeast.  The mixture produced a mash. The yeasts (small one-celled fungi) digest the sugars and carbohydrates in the mash and as a byproduct create alcohol and carbon dioxide gas. The mash is poured into a container and boiled. The steam goes into a condenser. Note the large boiling vat in the picture below and the condensing pipe that comes out of the top. The jars are filled with illegal moonshine.

Although Carver knew of this process, his interest was not to create alcohol for consumption, but to find interesting compounds that could be used for multiple purposes.

Esters

One kind of compound that is common in nature is the ester. There are many different kinds of esters that occur in fruits and vegetable matter. When we think of a fruity smell, the compound that we likely sense is an ester--an organic compound that has a distinctive pattern of structure. For example, the ester that gives the smell of apple is butyl acetate, diagrammed below.

This ester is used to flavor foods. It boils at 261 degree F and can be extracted from apples directly, or synthesized in the laboratory.  Other esters give different flavors.  The chart below shows some of these compounds.

To view a larger imager of the chart see: TABLE-OF-ESTERS-AND-THEIR-SMELLS-V2.PDF 

What esters or other compound might Carver have discovered as he tested different fruits, grains and vegetables often allowing them to ferment and then to distill the different liquids? Students can use the chart to smell available fruits and then attempt to extract that compound using distillation.  Does the extracted smell mirror that of the fruit? What is the utlilty of such a compound?