I have been thinking about demitasse cup shape lately. You see, most cups are about the same, whether it's the nova point moka brown ones or the IPO white cups and even the tulip shaped cups really fall into the same category. But I have one demitasse in my collection, a small brown cup from Germany, that, hands down, is the best demitasse for espresso I have used.
One of the key questions I have asked myself when looking to get the best out of a cup of coffee or espresso is: How do we capture and transmit the essential aromatics? As many know, it's the aromatics that are the most important factor in determining the flavor of the coffee. All things being equal, the better the presentation of the aromatics for the particular beverage, the more dynamic and richer flavor experience for the consumer.
That being said, the typical demitasse has an opening diameter of 2 1/16" to 2 1/4" and a height of about 1 7/8 to 2". This particular demitasse has in opening diameter of 2 1/2" and a height of 1 3/8". This wider opening, shorter and less tapered design creates more surface area for the crema and allows your nose to hit closer to the center of the cup rather than the edge. This essentially surrounds your nose with aromatics. Also, the way the flavors present themselves in the cup seem somehow more pronounced, beyond what the aromatics should provide. My theory is that the dispersion and layering of the espresso is different enough that it results in enough separation for greater clarity without losing balance.
While it's certainly not enough for a scientific trial, I've had about thirty shots of espresso to compare (60 total) on roughly 12 different espresso - both blends and SO, and I've pulled about eight shots for our best customer who gets espresso daily. The first time I made an espresso for him in this demitasse, I didn't say anything, and all he could say was "Wow!" to the same espresso he had earlier in the day, but in our normal demitasse. Every time we each remark at how good it tastes.
When it comes to the siphon, cup shape certainly matters to us. Now the best shape when it comes to the aromatics of the coffee, is actually a Champagne flute.. but at about 4-5 oz, expensive, and a general pain in the ass to keep spotless... it's not the most practical delivery system.
We therefore specifically use tapered or tulip shaped Japanese bone china, and a few German as well (for some reason, the handles on many of the German cups are oddly small). The cups are usually 7-8oz, but sometimes five. Larger doesn't make any sense at all. It's the same reason why you don't serve wine in a one liter boot or hefty stein. And the shape maintains the best aromatics out of the useable drinking vessels. A smaller cup with a smaller diameter also works well too. The nose isn't as pronounced in the beginning, but it will maintain a balanced clarity throughout.
One of the most important aspects of choosing the right cup, is raising the level of the coffee experience for the customer. To make coffee by the cup, and serve it in a paper cup is insane (and not the good kind!) . Or to serve it in the same ceramic you use for everything else really doesn't convey the specialty of what the customer is about to consume. How can we expect a customer to understand what they are receiving if we treat it the same as every other cup. And if EVERY cup is special, then treat every cup that way. Find the best way to prepare, and the best vessel to serve in, and in doing so you honor the coffee, the customer, and your business.