Vernor's Ginger Ale and high-grade vanilla ice cream. This works okay with Blenheim and should be fine with Fever Tree (sold as a drink mixer but excellent by itself) or even Ale-8-One,* but simply shines with Vernor's -- so much so that when I looked up the brand, I discovered the combination has its own name, a "Boston cooler." To my relief, this appears to have nothing to do with the East Coast city of the same name.
* Not, strictly speaking, a ginger ale per se; instead, it's a unique taste that is somewhat related. Quite regional -- I stumbled over a local supplier a couple of weeks ago. Highly recommended.
5 weeks ago