Chocolate Mochi (チョコ餅)
After making butter mochi a few months ago, which infuses the soft, chewy mochi with the creamy flavor of butter, I started to wonder what other kinds of hybrids between Japanese sweets and Western treats would be possible. Of course, as someone who’s addicted to all things cacao, my mind quickly wandered to chocolate mochi.
Inspired by chocolate truffles, which get their name from the knobby subterranean fungi from which they get their name, I created these decadent confections, which packs a triple dose of chocolate. In the center lies a sphere of chocolate ganache with a soft consistency that instantly melts in your warm mouth.
Since the ganache is too soft to hold its shape at room temperature, this is where the mochi comes in. By wrapping it in a thin layer of elastic mochi, it holds the chocolate together long enough to get it into your mouth. A generous dusting of cocoa powder outside keeps the mochi from sticking while adding an intense burst of chocolate.
Why This Recipe Works?
- Using mochi flour (as opposed to whole mochi rice) significantly simplifies the preparation of the mochi.
- Mixing high-quality cocoa powder into the mochi flour infuses the mochi itself with loads of chocolate flavor.
- Making a soft ganache and refrigerating it solidifies the chocolate enough to scoop it into spheres that you can wrap without making a mess. As it comes to room temperature, the ganache will soften again, leaving you with delicate mochi with an impossibly soft core.
Ingredients for Chocolate Mochi
- Dark Chocolate – Chocolate is the main component in the ganache. I used Valrhona Equatoriale Noire (55%) feves, but you could do this with any chocolate, including milk or white chocolate.
- Unsalted Butter – Butter gives the ganache a smooth, creamy texture and rich taste. The butter in the mochi keeps it from getting hard, especially after being refrigerated.
- Heavy Cream – The cream adds richness to the chocolate, while the liquid keeps the chocolate from setting completely at room temperature. This is what gives the ganache its melty texture.
- Mochi Flour – mochi flour, known as mochiko (餅粉) in Japanese, is simple short-grain glutinous rice (mochi rice) that has been milled into flour. This makes it significantly easier to prepare than the usual soaking, steaming, and pounding that needs to happen to turn rice into mochi.
- Cocoa Powder – While you could theoretically melt some chocolate and fold it into the mochi, it is much simpler just to use cocoa powder. I recommend using high-quality Dutch-processed cocoa powder (as opposed to a “natural” cocoa powder) for the best flavor and color. I used Valrhona Cocoa Powder.
- Sugar – You can cut back on the sugar a little if you use milk or white chocolate in the ganache as these tend to be sweeter, but for the 55% chocolate I used, you want a little sweetness in the mochi.
- Milk – mochi flour needs a liquid to turn it into mochi, and I like adding a little creaminess to it by using milk instead of water.
How to Make Chocolate Filled Mochi
The ganache needs about 4 hours to chill and firm up, so you’ll want to start with it. In a microwave-safe bowl, add the chocolate, butter, and heavy cream. Put the bowl in a microwave oven and set it to 600 watts for a minute and a half. If you can’t set the power of your microwave, you may need to reduce or increase the amount of time, depending on how powerful the default setting is (it should say how many watts it is on the back of the unit). You can also do this in a double boiler.
Once the chocolate and butter are about halfway melted, remove it from the microwave oven and let it rest for half a minute. This will allow the residual heat to melt the remaining chocolate without overheating it. Next, use a spatula to mix it until it’s smooth and velvety. Finally, cover the bowl and refrigerate for at least four hours, or until the chocolate ganache is very firm.
For the mochi, you want to start by lining a square baking pan with parchment paper. I used a 5×5-inch pan, but a bigger one will work.
Add the mochi flour, cocoa powder, and sugar to a large microwave-safe bowl and whisk together until the ingredients are evenly combined.
Add in a bit of the milk and whisk it together to form a paste. Continue adding a little milk and whisking until you have a smooth paste that’s free of lumps. Add the remaining milk and whisk it all together.
Pop the chocolate mochi mixture into the microwave and cook it at 600 watts for two and a half minutes. Remove the bowl and use the whisk to mash up any big clumps of solidified mochi. Add the butter and whisk everything together until the butter is fully incorporated. You may still have some small lumps, but this is fine.
Put the bowl back into the microwave oven and set it at 600 watts for another three and half minutes. Now you want to use a silicone spatula or wet wooden paddle to knead the mixture until it’s smooth and elastic. The chocolate mochi is hot and sticky, so be careful not to let it get on your hands.
Once the chocolate mochi is smooth and stretchy, spread it into the prepared mold in an even layer. This is not necessary, but it makes it a lot easier to divide the mochi into equal-sized pieces later. Let this cool to room temperature. You will want to cover the surface with plastic wrap once it has cooled to keep it from drying out.
Once the ganache is ready to use, unmold the chocolate mochi and cut it into 16 squares (4×4).
Use a round spoon or a melon baller (I used 1/2 tablespoon) to scoop a sphere of ganache out of the bowl.
Pick up a square of mochi and flatten it with your thumbs, so it’s about 2-inches in diameter. Be careful not to press any one area too thin, or it will tear when you stuff it.
Put the ball of ganache you scooped out earlier into the center of the mochi and then wrap the edges around the chocolate. The ganache will melt on contact with your hands, and it will prevent the mochi from sticking, so try not to touch it directly. Pinch the seams of the mochi to seal it shut.
Roll the mochi around in some cocoa powder to keep it from sticking, and then round out its shape with your hands, being careful not to tear through the mochi. Repeat with the remaining mochi and ganache.
Other Japanese Sweets Recipes
Mochi is a Japanese rice cake made by pounding glutinous rice into a tender, sticky cake. Chocolate mochi is made by filling this mochi with chocolate or by infusing the mochi itself with chocolate. In this chocolate mochi recipe, I do both.
Chocolate mochi is not a typical sweet in Japan, but if it were, it would probably go by the name Chocomochi(チョコ餅) or Choco Daifuku (大福); daifuku being the word used to describe mochi that is stuffed with something.
If you are eating this chocolate-filled mochi within a day, you can store them in a sealed container in a cool room; if you plan to keep them for longer than a day, I recommend storing them in the refrigerator. The ganache will solidify, but this can also be a fun texture. If you really want the center soft, you can put them in the microwave for a few seconds.
unsalted butter a little less than 3 tablespoons
For chocolate mochi
mochi flour ~1/2 cup + 2 tablespoons
cocoa powder 3 tablespoons, plus more for dusting
sugar a little less than 1/2 cup
unsalted butter 3 tablespoons
To make the ganache, add the chocolate, butter, and heavy cream to a microwave-safe bowl and put it in a microwave set to 600 watts for one minute and thirty seconds.
Let the mixture rest for an additional thirty seconds, and then stir together until it’s smooth and free of lumps. Cover and refrigerate until solid (about 4 hours).
To make the mochi, line a 5×5-inch pan with parchment paper.
In a large microwave-safe bowl, whisk together the mochi flour, cocoa powder, and sugar until evenly combined.
Whisk in the milk a little at a time until the mixture is smooth and free of lumps. Add the remaining milk and whisk until smooth.
Put the mochi mixture into the microwave and set it at 600 watts for two minutes and thirty seconds.
Use the whisk to break up any solidified lumps and add the butter. Whisk together until the butter is melted and emulsified with the mixture.
Microwave the chocolate mochi at 600 watts for an additional three minutes and thirty seconds.
Use a spatula or wet wooden paddle to knead the mochi until it is smooth and elastic. It is extremely hot and sticky, so be careful not to get any on your hands.
Dump the chocolate mochi into the prepared mold, spread the mixture evenly into the corners, and flatten off the top. Let the mochi cool to room temperature, and then cover while you’re waiting for the ganache to set.
When the ganache has firmed up, use a knife to cut the chocolate mochi into quarters in both directions to make 16 squares that are roughly the same size.
Use a round 1/2 tablespoon or melon baller to scoop a ball of ganache out of the bowl.
Use your thumbs and fingers to press out a piece of mochi into a 2-inch disk that’s roughly the same thickness.
Place a ball of ganache into the center and wrap it with the mochi. Pinch the seams together with your fingers to seal the mochi shut, and then roll the chocolate-filled mochi in cocoa powder to keep it from sticking.
Adjust the shape of your chocolate mochi ball as needed and repeat with the rest of the mochi and ganache.