A new kind of “gold standard” could soon permeate the whiskey industry.
Whiskey distilleries often aging spirits in charred wooden barrels for years, allowing the liquor to gradually absorb the flavorful chemicals released from the wood (Serial number: 10/31/19). Now, researchers have shown that spinning gold ions in a whiskey can reveal how much flavor the liquor has absorbed, a quality called aging. The method could provide master blenders with a quick and inexpensive test for the age of whiskeyresearchers report Oct. 6 in Nano materials applied by ACS.
“A small amount of gold gives you this really bright, strong, red, blue or purple color,” says William Peveler, a chemist at the University of Glasgow in Scotland. The stronger the color and the faster that color emerges, the older the whiskey, he says.
Master blenders sometimes hold tasting sessions to gauge aging, but this process can be labor intensive. Alternatively, laboratory tests can measure aging by checking whiskeys for flavorful chemicals called congeners, absorbed from wooden barrels, but such tests can be expensive.
Previous research has shown that various chemicals, from neurotransmitters a off-flavor compounds in maple syrup, could trigger gold ions in a solution to fuse into ultra-tiny gold nuggets or nanoparticles. So Peveler and his colleagues mixed solutions containing less than a penny worth of gold ions into different blends of whiskey and vodka. While no nanoparticles formed in the vodka, the ions reacted with congeners in the whiskey to form nanoparticles within minutes. The size and shape of the nanoparticles varied from whiskey to whiskey, causing the liqueurs to bloom with different colors.
The researchers plan to further investigate how gold nanoparticles grow along with alcohols and sugars in whiskeys to develop an even more comprehensive aging test.