Kohi zeri (coffee jelly) is a common dessert in Japan. You can find it everywhere - prepackaged at the conbini, at craft coffee shops like Maldive in Shimokitazawa, heck you can even get one fresh off the plane at Royal Coffee Shop in Narita. Kohi Zeri is so pervasive, that even Starbucks Japan came out with their own version in 2016.
So how did this dessert come to be? Its roots can be traced back to a quick mention of "coffee jelly" under the section "French Modes of Preparing Milk Coffee" in a British recipe book published in 1817 called the New Family Recipe Book. After the publishing date of this book, versions of coffee hardened with gelatin in elaborate molds started appearing in England.
Coffee gelatin skipped the pond, and gained some popularity in New England as Coffee Jello. Boston's Durgin-Park would use leftover coffee to make this "commoners" dessert. Even Jell-o released a version in the 1918. But it never quite took off in America, and is now rarely seen in the U.S.
No one is quite sure how this dessert skipped another ocean and made its way to Japan. This article does mention that there was a recipe for coffee jelly published in Yomiuri Shinbun, a newspaper in Japan, in 1914. I wish I could see this original recipe to see if this was when it was adapted for the Japanese by using agar agar instead of gelatin for the hardening agent. In 1963, Nakano-based Mikado Coffee chain, released a version of coffee jelly as "Taberu Kohi" or eating coffee. This took off and solidified coffee jelly into the Japanese dessert vernacular.
Knowing the history of coffee jelly, I'll never look at it the same again! So now onto the fun part – making it.
1. Add the water and kanten packet to a saucepan.
Mix while bringing to a boil.
2. Remove from heat and add sugar and instant coffee.
Mix well, approximately 1 minute.
3. Pour into kanten mold.
Let cool at room temperature, before putting in the refrigerator.
4. Keep in refrigerator for at least 2-3 hours until hardened and chilled.
5. Cut into cubes and serve with milk, heavy cream, condensed milk, or dollop of fresh whipped cream.
Now you don't have to traverse the pond for your coffee jelly cravings. Enjoy making this at home!