Paul Adams of PopSci:
"It takes only 48 hours to distill a barrel of whiskey. The next decade is spent making it taste good. The liquor undergoes constant chemical changes, some from the charred oak of the barrel itself, which acts like a sieve, trapping the large-molecule forms of alcohol (methanol, butanol) that give young whiskey such a rough edge. The process takes years, and as a result good whiskey is old and expensive. Four-year-old bourbon runs about $20 and tastes OK. But a truly delicious bourbon out of its teens will easily fetch $200.
However a South Carolina inventor has invented a way to age liquor overnight.