I had previously cured whole (peeled) eggs in tamari, but was intrigued by the idea of curing just the yolks using a similar process.

According to Cook’s Science, “The high concentration of salt from the curing liquid (soy sauce or tamari) draws out water from the exterior of the yolk, forming a thin, intensely savory exterior shell around a gooey, runny interior. You can put them on anything—ramen, toast, salads—but they’re perhaps best served simply on a hot bowl of rice.” 

That was enough to pique my interest.

The yolks are cured in a combo of tamari, sake, and sugar, which gives them a slightly sweet (with caramel-like undertones) and salty flavor profile. As for their texture, that’s the unusual part. I cured my yolks for approx. 20 hours, which resulted in a rather firmly set, almost gelatinous interior. Next time around, I’d probably give them a little less time (perhaps, 12 to 15 hours). I’ve seen recipes that call for curing the yolks anywhere from 8 hours to several days.

Some greens sounded good with the rice and cured yolks, so I made 0hitashi, Japanese blanched (spinach or mustard) greens in a dashi-tamari-mirin sauce topped with bonito flakes. And since I went through the trouble of making dashi, decided to use the leftover broth for miso soup. Thus, simple curiosity about cured egg yolks turned into a bit of a project, albeit a tasty one.

I used duck eggs and chicken eggs. The yolks from the duck eggs are noticeably larger (and a bit richer in flavor) than the yolks from the chicken eggs. Can you tell the difference?

After about 20 hours…

Egg jelly…

Tamari & Sake-Cured Egg Yolks

3.5 ounces (scant 1/2 cup) tamari
2.5 ounces (1/3 cup) sake
1.75 ounces (scant 1/4 cup) sugar
6 egg yolks

Whisk together tamari, sake, and sugar. Add egg yolks. Cover with plastic. Cure 8 to 24 hours in the refrigerator, depending on how set you like your yolks.