Remember those beautiful edible “jewels” that we shared with you a couple of weeks ago? Made simply from sugar, agar-agar, and a beverage of your choice, the jewels are both pretty to look at and make a cool – in both senses of the word – summer treat.

They’re still all the rage right now on Japanese social media, so our Japanese reporter Shimazu decided to try making some jewel flavor combinations for herself. She even experimented with three different manners of preparation–serving them right away, freezing them, and letting them sit for a few days to harden.

Which method of making them do you think she enjoyed the most?


We recently shared the specific recipe and cooking instructions for making kohakutou (琥珀糖; literally “amber sugar”), which is the formal name for the traditional, rock candy-like treat in Japanese. The sweet has been experiencing a wave of popularity ever since a Japanese Twitter user made the following post about how to create them:

Using the original Twitter recipe as a guide, our reporter Shimazu decided to experience making the jewels for herself. Join her as she completes the step-by-step directions from scratch, and later experiments with three different methods of serving them.


▼ String-type agar-agar

Step 1: Soak 5 grams* of string-type agar-agar in water for 12-24 hours.

For those of you who can’t wait that long, Shimazu says you should be able to use powdered agar-agar instead, which doesn’t need to be soaked in water. Just keep in mind that the stringy type appears to come out more transparent at the end.

Step 2: Drain the water and place the agar-agar in a pot with 200 milliliters of fresh water. Heat on medium heat until it’s completely melted.

Step 3: Sieve the mixture over another pot, then add 350 grams of granulated sugar and melt it until it’s frothy and stringy.

OK, folks, from here on out we’ll be exclusively documenting the creative work behind Shimazu’s own original creations!

Step 4: Pour a tablespoon of your favorite juice or beverage into some type of empty vessel, such as a milk carton. Fill the rest of it with the agar-agar/sugar mixture. Shimazu says that as long as it’s drinkable, pretty much any kind of liquid is game!

Here are the five drinks that she rounded up for experimenting with (translator’s note: somebody make me a cassis oolong!!):

From left to right, pictured here are green (“white”) grape juice, crème de cassis liqueur, peach juice, purple grape juice, as well as Shimazu’s personal favorite, Kirin’s Green Label beer. 

The reason she bought three kinds of juice was because she really wanted to make some bluish jewels, but couldn’t find a suitably colored juice to use. Her last hope was that at least one of these opaque cans of juice would contain something like the color she wanted, but to her chagrin, none of them did.

Even the white grape juice, which she was hoping to be a light green color, turned out to be nothing more than a muddied yellow; similarly, the peach juice was a translucent white.

In her disappointment, she decided to mix all three of the juices together, and ended up with a pale pink mixture that was actually pretty decent:

In any case, let’s move on to the final steps!

Step 5: Chill the containers in the fridge until they’ve hardened, then remove them from their molds and cut the block into smaller pieces however you like.

According to Shimazu, the mixtures hardened rather quickly. The cassis liqueur became a lovely, deep shade of violet, the juice combination stayed a light peachy color, and the Green Label beer turned into a golden amber. She says “became,” but the difference in color before and after they firmed up wasn’t incredibly substantial, to be honest.

Serving Method #1: Eat them right away!

Maybe it’s because of all the sugar in them, but it actually took a lot of strength for Shimazu to cut the ready-made blocks.

But all that effort paid off, because the “jewels” were delicious when she tried them! Again, it was probably due to the large quantity of sugar inside of them, but Shimazu noted a surprising crunching sensation along with the jelly-like consistency while she was eating them.

The alcohol in the crème de cassis had disappeared, but its aroma remained intact. The blended juices also retained their fresh and fruity taste. Shimazu was expecting the beer jewels to still smell like alcohol, but like the cassis ones, there was no hint of the smelly booze. In fact, the bitterness itself had also vanished, to be replaced with a fresh and sweet flavor in its place.

When eating the jewels right out of the fridge like this, she came to the conclusion that they had a light and pleasant aftertaste, along with an enjoyable texture. Get ready, however, because she’s about to introduce two other ways to serve the jewels!

Serving Method #2: Freeze them!

If you enjoy sampling frozen treats, then this might be the perfect way for you to prepare your jewels.

Shimazu notes that the frozen jewels are reminiscent of the half-frozen gelatin desserts that Japanese schoolchildren occasionally find in their school lunches during the summer months. Once the water portion inside of them freezes, they even seem to expand a bit, adding an additional crunchy texture to your treat.

In this form, the jewels have the sweetness of traditional Japanese confectioneries, yet the consistency of some typical Western hard candies. About the only downside to freezing them is that they lose their transparent quality to a degree and become a bit murky looking instead.

Serving Method #3: Let them sit for several days!

While Shimazu thought that the freshly cut, ready-to-serve jewels mostly resembled clean-cut diamonds, she was still a bit baffled as to why their Japanese nickname (taberareru ishi; “edible rocks”) involved the word “rocks.” What was so rock-like about them? It turned out that she was able to answer her own question in just a matter of days.

When she let the pieces sit in an undisturbed area for three to five days as instructed to under the third serving method, here’s what they turned into:

The sugar had definitely crystallized, giving them the appearance of rough, jagged rocks. It even felt as if she were holding an actual rock in her hand!

Upon tasting them, she discovered that the crunchy sugar coating contrasted wonderfully with the still-soft interior. The texture and the taste were so fantastic; the jewels could have passed for first-rate candy! Their outer-inner appearance was also quite pretty to look at:


Shimazu enjoyed all three different serving options of the jewels, but her favorite variation was definitely to let them sit in the open air for a few days and become hard on the outside. Compared to the other two variations, this one overwhelmingly felt and tasted like a perfected sweet to her.

Making your own edible jewels isn’t very demanding, so cooking novices and seasoned veterans alike should have fun crafting their own unique flavor combinations. Let us know the results of your home experimenting in the comments section below!

▼ Our reporter Shimazu, sampling the fruits of her labor

▼ “Hey, it’s pretty good!”

Recipe source: Twitter (@Crab000)
All images © RocketNews24
[ Read in Japanese ]