That reminds me of the first batch of Blind Man Espresso Stout, a microbrew that was made here several years ago. John Gayer, the brewer, used dark roast beans that had so much caffeine in them that we who tried it that first night (I drank 5 pints) couldn't get to sleep until the next afternoon.
My mother, who was 84 or 85 at the time, thought it was a screamingly funny mistake; she made an important observation: "Tell John to use 50% decaf beans, if he can find them in dark roast. Surely they can be had. That ought to solve the problem."
Next batch, he took her suggestion verbatim. The brew tasted the same and we managed to get to sleep after quaffing several pints apiece.
Today, this same brew rotates in availability with two or three other Stouts and Porters at Copper Creek Brewing here; the brewer, Matt Buley, was John's assistant. His version is superb, and won't rob anyone of sleep... he uses roughly 75% decaf!
Two Cups Are Enough (But That's Not Revealing The Size Of My Cup!), Ort. Carlton in 30601-land.