Sushi enthusiasts often regard sea urchin (Uni) as the perfect finish to a delightful meal. However, amidst the Uni lovers, there exists a group who simply can't appreciate its unique taste and texture. When you ask these individuals why Uni doesn't appeal to them, they commonly cite bitterness, a medicinal or chemical scent, and sometimes even a fishy odor. Interestingly, one of the factors contributing to these perceptions seems to be "myoban." To uncover the truth behind Uni and its relationship with "myoban," I sat down with Kimi from Hokkaido Uni Shop.
Q: Right away, Kimi-san, what is "myoban"?
A: "Myoban" is potassium aluminum sulfate, a substance often used for various purposes such as removing bitterness from sweet potatoes and chestnuts or enhancing the vibrant color of pickled eggplants.
Q: Why is "myoban" used for sea urchin?
A: Sea urchin, when rinsed in water containing "myoban," becomes more resistant to dissolving. Therefore, most of the sea urchins you find outside their place of origin have been treated with this "myoban."
Q: Does sea urchin easily lose its shape?
A: Yes, sea urchin has a tendency to absorb air, and when it oxidizes, it tends to develop an unpleasant odor. If sea urchins are left untreated after harvesting, they are prone to dissolve. Immersing them in seawater with "myoban" serves to preserve their structure.
Q: Many people often say they can't eat sea urchin because it smells and tastes bitter. It seems that "myoban" is somehow related to this. What can you tell us about this?
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A: It's a common misconception that bitterness, medicinal aromas, and fishy notes are linked to "myoban." In reality, "myoban" can help sea urchins maintain their natural shape and enhance their inherent umami. Sea urchin itself may have a subtle bitterness.
What we consume as "sea urchin" is actually the gonads of the sea urchin. These gonads store nutrients when the sea urchin is not reproducing, gradually increasing in size. As spawning season approaches, the proportion of reproductive cells within the gonads rises, while the nutrient cells decrease. This period is considered the sea urchin's "prime." However, after this period, as the reproductive cells continue to increase, the gonads start to release eggs or sperm, leading to the "dissolution" of the body and a decline in taste. This is what people often describe as "bitterness."
Furthermore, the quality of sea urchin is heavily dependent on its origin.
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Q: Regarding the origin, we understand that factors such as seawater temperature and the quality of kelp, which is their food, play a role. But how do producers come into play?
A: Skillful producers can expertly adjust the concentration of "myoban" to create high-quality sea urchins. Excessive use of "myoban" can impart a specific bitterness to the sea urchin. Thus, the lower the quality of the sea urchin, the more "myoban" is used. If the sea urchin is already of poor quality, using a significant amount of "myoban" to maintain its shape can further degrade its taste, intensifying the aroma and bitterness.
Q: I see... So, it's like making something that's not originally delicious even less delicious.
A: Preparing sea urchin is a meticulous process. The shells are carefully split in two, and the yellow gonads or sperm are extracted. Any remaining waste or organs are diligently removed. If any remnants are left behind, it can result in a crunchy texture and a seaweed-like aroma. Those who carry out these intricate tasks are what I refer to as "producers."
Q: So, such intricate work is required for delicate sea urchins, and that's why precise work is demanded.
A: Exactly. That's why we always check the origin, even at the auctions.
In conclusion, while "myoban" plays a role in preserving the form of sea urchins and may sometimes be associated with bitterness, it is by no means the sole determinant of Uni's flavor. The origin of the sea urchin and the expertise of producers also play pivotal roles in delivering a delectable Uni experience. So, the next time you savor Uni at a sushi restaurant, remember that there's more to its taste than meets the eye – it's a harmony of nature and craftsmanship.