On an unusually balmy day in Scotland's Speyside region, the sun shone brightly down on the warehouses and trademark pagodas that dot the grounds of the Glenfiddich distillery. Scotland is famous for being misty, gloomy, and chilly—in the most wonderful and atmospheric way. But there wasn't a cloud in the sky or a drop of rain in sight. It might not have seemed like Scotch-sipping weather. But after touring the distillery grounds, I visited one of the oldest warehouses onsite, where...