Green soybeans are boiled, shelled, and then skinned one by one before anything else can happen. That last step is the work. The thin membrane on each bean has to come away, one bean at a time, and there is no machine in a home kitchen that will do the job for you.

Sugar goes in, and a pinch of salt, and the beans are ground in a heavy ceramic mortar until they become a coarse green paste. Wrapped around pounded rice cake, the colour is startling. In photographs it comes out brighter than it is; in front of you it is a pale, dusty green, and the best versions leave some of the grain intact rather than working it smooth.

Because the beans come in summer, zunda belongs to summer. In Sendai the busy stretch runs from Tanabata in early August through the Obon holidays, and in many houses the sweet was made as an offering for the family dead rather than as a treat for the living.

Freezing arrived in 1989 and the season quietly stopped mattering. It is available all year now, which is convenient, and which has made it easy to forget that the sweet used to mean August and nothing else. The colour still says summer even when the calendar does not.