Kuro Tamago

Eggs boiled in Hakone's volcano

Kuro Tamago or Black Eggs are one of Hakone’s trademark items.  This unique snack can only be found while at the volcanic valley of Owakudani. A small hut along the side of the volcano cooks and distributes the eggs here. Boiled inside of the hot sulfur springs, the eggs emerge their namesake black in color.

You’ll probably find a crowd gathered outside of the Kuro Tamago Shop at any point. Getting there will require some effort but since it is also the pinnacle of Owakudani (and thus Hakone), most visitors will want to take the climb up.

The shop atop Owakudani.

The Kuro Tamago are sold in packs of 5 for 500 yen. Which is kind of pricey as far as eggs are concerned but perhaps not so outrageous as other souvenir or novelty snacks. It might be the reason why Kuro Tamago enjoys enduring popularity, even among the locals. Business is amazingly good, with hundreds of people coming and leaving the shop each hour.

Sold in packets of 5 only.The famous black eggs.Bought a pack.

Legend has it that eating one of the black eggs increases one’s lifespan by 7 years but it is also said that one should not eat more than two and a half eggs (the “or else” is not explained). No real source can be accounted for this tale, except the shop of course. It is further suspicious that each packet comes with this exact serving for two. Everything seems to point toward the legend being popular modern myth.

The famous black eggs.

Unlike regular onsen eggs, Kuro Tamago are hard boiled. The egg shells turn black due to a chemical reaction with the sulfur in the springs. Fear not as the trace amounts of sulfur in itself is not poisonous. Small amounts of sulfur is often used in medicine, which might also explain the longevity effects claimed by the eggs.

Spending too much time breathing in the sulfuric gases from the vents is a different question though. But the shopkeepers and their cats seemed to have built up an immunity to it.

Just like regular eggs.

500 yen is a small sum to experience this amusing snack. But if you’re not very fun, do take note that sadly, the sulfur does nothing for the flavor of the eggs (which might not necessarily be a bad thing). Peeling away the black shell, you’ll find that Kuro Tamago are identical to normal hard boiled eggs when it comes to everything else other than appearance. For this reason, each packet of eggs come with some salt for those who find them too bland.