Ack! There is no way to make this palatable. Even after finding the bottom of another double long I still can't get the taste out of my mouth. Our first attempt with about half a teaspoon was simply overpowering. It was too much of the spice and all flavour of espresso was obliterated. Even tempered with milk and sugar, the mouth-feel was gritty. Tongue crushingly bad. In espresso infusion experiment history, this was the first time we both needed a glass of water and some recovery time.
The second attempt was just a light dusting over the bottom of the holder. This turned out to be a bit of an overcompensation. The flavour was completely lost in the coffee. A fine brew, but with nothing added it was bound to be.
Third and finally, we added an amount somewhere in the middle, a light spattering to just cover the filter. The balance between coffee and allspice seemed right, but a sip was still too much. The flavours simply don't work together. Adding milk, then sugar, didn't change our opinions about it. The combination can only be described as unpleasant.
Today's results surprised me because, judging by the smell, I really thought they would work well together. When I asked a chef friend of mine for her professional opinion on what flavours would infuse well with espresso, this was the first thing she recommended. It was already on the list but it goes to show I wasn't the only one who thought the combination would blend nicely. The only way I think allspice might work is in a blend of spices, mixed with ginger, cinnamon, nutmeg, and/or clove to achieve a kind of gingerbread coffee effect. Alone it seemed to dominate or be undetectable with no middle ground.
It was bound to happen, something that didn't work and has absolutely no potential worth pursuing. Kinda takes the pressure off. At least it would if there were any pressure to begin with. We learned something, so I'll still consider today's tasting a win.