"But the potential was clear. Soon, by exposing large numbers of seeds and young plants, scientists produced many more mutations and found a few hidden beneficial ones. Peanuts got tougher hulls. Barley, oats and wheat got better yields. Black currants grew.
The process worked because the radiation had randomly mixed up the genetic material of the plants. The scientists could control the intensity of the radiation and thus the extent of the disturbance, but not the outcome. To know the repercussions, they had to plant the radiated material, let it grow and examine the results. Often, the gene scrambling killed the seeds and plants, or left them with odd mutations. But in a few instances, the process made beneficial traits.
The payoff was even bigger in Europe, where scientists fired gamma rays at barley to produce Golden Promise, a mutant variety with high yields and improved malting. After its debut in 1967, brewers in Ireland and Britain made it into premium beer and whiskey. It still finds wide use.
“The secret,” reads a recent advertisement for a single malt Scotch whiskey costing $49.99 a bottle, is “the continued use of finest Golden Promise barley and the insistence on oak sherry casks from Spain.”"