Step 1: Create the Mud
In a clean container, add water to the dirt. The ratio of water to dirt will vary depending on the type of dirt. Start by adding a small amount of water, mix, and slowly add more water until the mud reaches an even consistency, similar to dough.
Step 2: Create the Core:
Grab a handful of mud and begin to shape it into a sphere with both hands, squeeze out as much water as you can. Eliminate irregularities from the mass by gently shaking it. The vibration removes voids, increases surface moisture, and facilitates compaction. As you shape/shake the mud, clayey particles will migrate to the surface, forming a slip layer that will make it easier to smooth the mass into a sphere. Proceed to Step 3 when the ball becomes tacky to the touch.
Step 3: Create Preliminary Capsule
Holding the ball in one hand, grab handfuls of dirt with the other and sprinkle the dirt over the ball. With your thumb, gently sweep the excess off, rotating the ball as you do so. Use the outer curvature of your thumb, near the base, to do this. Fumio Kayo has a great video that demonstrates this technique. The newly added dirt will absorb the surface moisture very quickly. Work the ball to point where it retains its shape but isn’t so dry that cracks begin to form.
Step 4: Draw the Moisture Out
Insert the ball into a plastic bag. At first, you will only need to do this for 20 minutes or so. Be careful to lay the ball on something soft to prevent a flat area from forming. Water will condense on the inside of the bag and the surface of the ball will become wet again. Remove the ball and repeat Step 3. Return the ball to the bag before cracks begin to appear.
Repeat steps 3 and 4 until the ball begins to feel leather-hard to the touch. You will find that it takes longer for water to condense on the inside of the bag – you can accelerate the process at this point by putting the bag and dorodango in the refrigerator. Note: This will cause the water to condense very quickly, be careful to remove it before too much water condenses out – it will dissolve the ball where it gathers at the bottom of the bag.
Step 5: Create Final Capsule Layer
The brilliant shine of the dorodango is created by applying a final layer of extremely fine particles of dirt. I use two different methods to do this:
On-Site – When you have unlimited access to the dirt that you’re working with, simply pat the dry dirt lightly with your hand. Gently rub the fine particles that stick to your hand over the ball.
Off-Site – When you have limited access to the dirt you’re working with, screen the dirt into a plastic container with a lid – a regular window screen works fine. Place the lid on the container and shake. Note: If the lid of the container doesn’t seal completely, be sure to wear a dust mask. Wait a few minutes for the dust to settle. Remove the lid; there should be an abundance of very fine dust sticking to the sides. Rub the dust into the ball.
Continue this process until the surface moisture of the ball has been completely absorbed (it looks and feels powdery). Insert the ball into a new plastic bag. Repeat this step as many times as possible to create a thick capsule. When the fine particles no longer adhere to the surface of the ball after you take it out of the bag, you’re ready to begin polishing.
Step 6: Polishing
Remove the ball from the bag and let it dry for 20 minutes. Polish with a soft cloth – carefully at first – if any moisture is present, the cloth will mar the surface. Polish or buff more vigorously once the ball is dry.