Spring is a great time for fans of wagashi, traditional Japanese sweets. While many wagashi reflect the seasons all year long visually — especially the colorful, beautifully formed nerikiri created by skilled artisans — this is the time of year when you can taste, as well as see, the season as it progresses.
In March and early April, there are sakura-mochi that use salty, tangy preserved cherry blossoms as well as leaves for flavor. And later on in May, there are kashiwa-mochi, wrapped in woodsy kashiwa (oak) leaves, as well as chimaki, which use young green bamboo leaves as wrappers.
One of my favorite springtime wagashi is kusa-mochi, which means “grass mochi,” also known as yomogi-mochi, made with the young leaves of yomogi — Artemisia princeps, sometimes called Japanese mugwort (it differs from European or common mugwort, Artemisia vulgaris). Kusa-mochi was originally made with a plant called hahako-gusa (Gnaphalium affine), which is one of the seven herbs of spring, and enjoyed by the nobility during the Heian Period (794-1185).
In the Edo Period (1603-1868), kusa-mochi started to be served during Momo no Sekku, the Girl’s Festival held on March 3. But hahako can also be translated to mean “mother-daughter,” and tearing apart a food containing “mother-daughter plant” leaves was considered to be unlucky on a day to celebrate girls.
So the yomogi plant started to be used instead of hahako. (Mochi sweets containing yomogi leaves existed in China too, where the idea may well have been copied from.) An advantage of using yomogi is that it is free, since it grows wild almost everywhere in Japan. Even now, yomogi grows in abundance in the poorest soil, along roadsides and in empty lots: It’s a rather invasive, perennial weed. The plant’s vigor is one of the reasons why it’s also used as a medicinal plant throughout East Asia.
Yomogi-mochi comes in many different shapes, depending on which area of the country you’re in. The common factor is the tender dough that is made with short-grain or mochi rice, sugar and/or mizuame (a sweet syrup derived from starch) and yomogi. The dough is a subdued green color, and has a refreshing fragrance and flavor. The green color of the mochi symbolizes new life and growth. The most common type of yomogi-mochi involves the green dough bring wrapped around a dollop of an (sweet adzuki bean paste) in a round or taco-like shape, but sometimes the dough is served as is, rolled out and cut out into squares or diamond shapes.
Making mochi sweets is quite difficult if you start with uncooked rice, which first has to be steamed and then pounded, but shiratamako, a steamed short-grain rice flour that was invented hundreds of years ago, simplifies the process considerably.
Jōshinko, which is made in a similar way from medium-grain rice, is also added for more texture. If you use fresh yomogi, only pick the young, tender leaves, and make sure it’s actually yomogi, not another plant that could be poisonous! Yomogi powder is available by mail order or from well stocked supermarkets. For this recipe, I’ve specified store-bought an, but homemade would be even better.
Yomogi-mochi: Mochi cakes with a seasonal twist
Ingredients (makes 10)
• 100 grams shiratamako flour
• 50 grams jōshinko flour
• 40 grams white sugar
• 5 grams yomogi powder or about 100 g fresh yomogi leaves
• 120-150 milliliters water
• Katakuriko (potato starch flour)
• 200 grams tsubu-an (chunky sweet adzuki bean paste) or koshi-an (smooth adzuki bean paste)
To make yomogi-mochi:
If the bean paste is too loose, cook it in a pan over low heat while stirring until the moisture evaporates and it becomes a stiff paste (it will get stiffer when it cools). Cool, and divide into 10 portions. Form each portion into a ball. Dust a baking tray or large plate generously with the katakuriko.
If using fresh yomogi leaves, wash very well. Bring 1 liter of water to a boil and add 1 tsp. of salt. Boil the leaves for 2 minutes, drain and cool under running water. Squeeze out well, and puree by pounding it using a mortar and pestle, or use a food processor if you have a small bowl attachment. Measure out 25 g of the puree. (Any left over can be frozen.)
Mix the shiratamako, jōshinko, sugar and yomogi in a microwave-safe bowl. Add 140 ml water if using yomogi powder (120 ml if using puree) and mix well until it forms a smooth, thick paste.
Microwave on the high setting, uncovered, for 1 minute. Beat the paste vigorously with a wooden spatula. Microwave for another 2 minutes, and beat and mix again. Repeat at 30 second intervals until the paste has thickened to a fairly thick yet still soft dough.
While the dough is still hot, but cool enough to handle, divide into 10 portions with moistened hands and form into balls. Flatten each ball with your hands on the katakuriko in the tray, and wrap around the bean paste. These should be eaten the day they are made.
For variety, use kinako (roasted ground soy beans) mixed with a little sugar and a pinch of salt instead of the katakuriko.