Dry Hop with Citra hops, 7-10 days in secondary. You will get a sour twang, with a citrus feel to it. If you just want it very slight, dry hop for a bit less.
Amarillo is good for some twang too..I think it has more of a grapefruit twang, but I always seem to detect grapefruit in Citra too, though some say its a bit sweeter like a cross between a mango and a grapefruit, Cascade, Centenniel.
I just said Citra above because we just did an Imperial IPA, and dry hopped with Citra for 10 days, the first sip makes your mouth slightly pucker, each one after that the citrus flavor just bursts out. Then the next beer goes down ridiculously smooth, but yeah..thats because the first was a 9.7 % 22 oz.
Abbey Ale #2
Rye Imperial Pale Ale
20 Gallons of Apple Cider
Bourbon Vanilla Imperial Porter