Decaffeinated Corpse, by Cleo Coyle

Trouble is brewing again for coffeehouse owner Clare Cosi. An old friend of Clare and her ex-husband (who is co-owner of the Village Blend) has developed a botanically decaffeinated strain of coffee. And the Village Blend has an exclusive on the introduction of the beans and coffee, a real coup. But the friend is mugged behind the coffeehouse and though they try to pass it off as nothing, Clare knows better. And when a body turns up, she's off and running again. With an ex-husband, a detective (and wannabe boyfriend), mother-in-law, old friends, and assorted barristas thrown into the brew, Clare has her hands full.

The Coffeehouse Mysteries always conain coffee lore and recipes, so if you're a coffee lover these are definitely the mysteries for you! Even if you're not (alas, I gave up coffee ten years ago) they're still fun, with engaging characters.