How to Make Sizzling Yaki-imo
How to Make Sizzling Yaki-imo: The Secret to the World’s Sweetest Potato
If you walk through a supermarket in Japan in autumn or winter,
you’ll notice it right away.
the warm, sweet aroma of yaki-imo (stone-roasted sweet potato).
In the past, you would often find yaki-imo sold by street vendors.
These days, it’s much harder to come by.
Yaki-imo is one of the simplest foods in Japan.
But because it’s slowly roasted over hot stones,
it becomes incredibly soft, moist, and naturally sweet.
To recreate that at home, you need just one extra step.
But when it’s done right, it becomes something truly special.
Soft. Moist. Almost syrupy.
So sweet, it tastes like honey—without adding any sugar.
Today, I’ll show you the quiet “secret” behind it.
The Secret Begins with Salt Water
The first step surprises many people.
Before cooking, we soak the sweet potatoes in salt water.
This simple step helps draw out the potato’s natural sweetness
and creates that signature moist, syrupy texture.
Golden ratio:
- 2 liters water
- 1 tablespoon salt
Soak for at least 6 hours, or overnight.
In Japan, this type of sweet potato is sometimes called
“mitsu-imo” (honey potato)—and this is where it begins.
The Two-Stage Cooking Method
To achieve that deep sweetness, temperature control is everything.
If the heat is too high at the start,
the outside cooks too quickly—and the magic never happens.
Step 1: Gentle Cooking
Place the soaked sweet potatoes in a rice cooker
with about 1 cup (240 ml) of water.
Cook using the regular rice setting (about 45 minutes).
This gentle, even heat allows the starch to slowly convert into sugar,
creating a soft, almost custard-like texture.
Step 2: Finish with Heat
Once the sweet potatoes are fully cooked and tender,
transfer them to an oven or air fryer.
Bake at 200°C (400°F) for about 10–20 minutes,
until the skin becomes slightly crisp and caramelized.
This step enhances the natural sweetness
and creates that signature syrupy texture inside.
The Result: Nature’s Candy
Break it open, and you’ll see it!
a golden, glossy interior,
soft, rich, and naturally sweet.
No sugar. No additives.
Just time, technique, and the power of nature.
What Comes Next
If you can resist eating them all…
these yaki-imo become the perfect base for
hoshiimo (sun-dried sweet potatoes)—
a chewy, concentrated version of this same sweetness.
I’ll be sharing that next.
