Design a striking cover for an immersive barista manual

Ac-cent-tchu-ate

This is a barista manual targeting coffee professionals working in 'third wave' coffee shops: baristas, barista trainers, cafe owners.

Please design an eBook cover that stands out as a thumbnail on the iBooks or Amazon store (see the attached images of both stores). The image needs to be striking and be able to stand by itself without text. The background needs to be able to work for both portrait and landscape as with the Kate Atkinson book shown in both formats on the iBook store (image attached).
Please supply two versions: one with text and one without. The title is "Coffee for the mildly obsessed". Author is Michael Wilson. Publisher Ac-cent-tchu-ate.
The manual has chapters on flavour perception, grinding, coffee, espresso, tea and chocolate.
I'm not looking for a cup of coffee or a coffee bean on the page. Please be creative. I need it to look different from all the other coffee books out there.

The kind of cafes these people work in are the high end coffee shops where the flavour of the coffee is very important and they source their coffee from coffee roasteries that deal directly with the coffee farmers - these cafes don't use syrups.