Karume

Karume
Daiso Japan, $1.50

Thanks to Daiso, the Japanese "dollar" store, you can try a treat that would have been familiar to children living in Japanese cities more than 100 years ago.  

Karume are feather-light hard brown lumps with hexagonal sides and ravaged-looking tops.  Pop one in your mouth for a rather straightforward brown sugar flavor and a comparatively intricate textural experience:  the porous sweet slowly erodes from the inside out and collapses in on itself in a jumble of shards and syrup.  

Karume are a kind of dagashi, a category of "cheap sweets" that became popular among urban children during Japan's Meiji period, when increased foreign trade made sugar affordable for the masses. 

According to Eric Rath in Food and Fantasy in Early Modern Japan, the historic precursor to our modern factory-formed karume was called karumeyaki, and it was then as much as taste of the future as karume is now a taste of the past.  Although the -yaki suffix is more usually attached to something that has been cooked or grilled, these candies get their bubbled appearance and hard shell from a chemical reaction caused by the addition of baking soda--an ingredient first introduced to Japan in the Meiji period.

This reaction is so spectacular that a university handout I found characterizes karume-making as a science experiment rather than a recipe.  In essence, you beat egg whites to a soft froth, stir in baking soda, then combine the egg with melted brown sugar.  The mixture foams furiously, and the bubbles can be hardened by cooking over a gentle flame.