Historically, coffee and booze played nice in mug-worthy drinks. But hot beverages are hardly appropriate during the year's sweatiest months.

Coffee lovers have long buzzed about the cold-brew method, dubbing it the ideal process for iced coffee. Now, distillers and bartenders are catching on, too: A spate of new, delicious coffee liqueurs have joined the trailblazers, and each uses cold-brewing to extract optimum flavor.

The generally excellent distillers at House Spirits in Portland, Oregon, have released an excellent liqueur--made with Stumptown beans, natch. And neighboring New Deal Distillery has two coffee liqueurs--each made from a different roast.

The process is simple to replicate at home with the Toddy Cold Brew system ($38; click here to buy). Substitute high-proof vodka or rum for water, and add sugar to the final product for a liqueur that matches beautifully with everything from bourbon to ice cream (click here to see the recipe).

And caffeinated booze is getting play among bartenders as well: In the coming weeks in New York, bartenders are pairing with baristas in a competition to create an ideal coffee cocktail.