Water and Kamaboko

The Unique Water of Hamacho, Odawara

Water plays a crucial role in the production of kamaboko (traditional fish cake).
Let us explain why we place such importance on the water in this specific region of Hamacho, Odawara.

Protein and Water Interaction

From a chemical perspective, water is essential in maintaining the structural integrity of proteins.
Proteins rely on interactions with water molecules on their surfaces to stabilize their three-dimensional structure.
Inside the protein, atoms are bound as tightly as in a crystal lattice.

Water's pH and Protein Stability

Water can be alkaline, neutral, or acidic, depending on its concentration of hydrogen ions, commonly measured using the pH scale.

Neutral pH

A pH of 7 at 25°C and 1 atmosphere of pressure.

Alkaline

A pH above 7 indicates increasing alkalinity.

Acidic

A pH below 7 indicates increasing acidity.

The Water-Leaching Process in Kamaboko Production

As previously explained, the three-dimensional structure of proteins is maintained through interactions with water molecules.
Changes in pH can affect these interactions, altering the properties of the proteins.
Proteins are formed by ionic bonds, and the electrostatic attraction between negatively charged acidic amino acids and positively charged basic amino acids is the source of their strength.

• A pH range of 4 to 10 is considered natural.
• If the pH drops below 4, the acidic amino acids lose their charge, leading to acid denaturation.
• If the pH rises above 10, the basic amino acids lose their charge, resulting in alkaline denaturation.

When the pH moves outside the natural range, the electrostatic attraction is lost, causing the protein's three-dimensional structure to collapse.
This process is known as pH-induced protein denaturation.

The Water-Leaching Process in Kamaboko Production

In the process of kamaboko-making, a key step is called "mizuasarashi" (water-leaching).
After the fish flesh is carefully separated from the skin, the raw flesh, known as "otoshimi," undergoes a process where it's washed multiple times in fresh water.
At Yamashita Kamaboko, we meticulously adjust the amount and frequency of water used, ensuring the perfect balance depending on the fat content of the fish.

This process removes unwanted blood, fat, and fishy odors, while also contributing to the final product's pristine white color, firmer texture, and improved shelf life.
The texture of kamaboko—referred to as its “foot” in Japan—gains resilience through this vital step.

Another important benefit of the water-leaching process is the removal of allergenic substances.
The main allergen found in fish is parvalbumin, which, during water-leaching, is eliminated along with the myofibrillar proteins.(※1)

References

※1 Tokyo University of Marine Science and Technology, Department of Food Science and Technology
Yuki Hamada, Erina Genga, Michitaka Ohira, Yuji Nagashima, Kazuo Shiomi
"Allergenicity of Fish Paste Products and Alaska Pollock Surimi," p.42 (Journal of Food Hygiene Vol. 41 No. 1, 1999)

The Importance of Water Quality

The water-leaching process uses an astonishing 10 tons of water per hour.
The water's pH level directly affects the stability of proteins, making the water’s quality critical for the perfect kamaboko.

Yamajou Kamaboko Shop is located between the Hayakawa and Sakawa rivers, drawing groundwater from two wells—one deep well reaching 100 meters underground, and a shallow well reaching 20 meters below the surface.

Deep Well

This water source is a confluence of the Hayakawa River, flowing from Mount Hakone, and the Sakawa River, originating from the Nishitanzawa Mountains.
Rich in calcium and magnesium (50–70 mg/L), this water is classified as moderately hard, with a higher mineral content than Odawara’s tap water.

Shallow Well

This water contains trace amounts of sodium, influenced by nearby seawater, though it retains a fresh taste without any noticeable saltiness.

The blended water from these two wells is abundant in minerals, and while it fluctuates slightly with the seasons, it typically has a pH of 7.4 to 7.8.

The Relationship Between Guchi Fish and pH

The optimal pH for the water used in the leaching process varies depending on the type of fish.
The guchi fish, used for making Yamajou Kamaboko, achieves the best protein binding and a perfect balance of tenderness and elasticity when leached in water with a pH of 7.4 to 7.8, created by mixing the two well waters from Yamajou Kamaboko.

If the pH exceeds this range, the dehydration process after leaching becomes less effective, resulting in a softer texture.
If the pH falls below this range, the texture becomes less cohesive and lacks elasticity.

Pure and Unaltered: The Natural Gift of Odawara's Water

Japan is generally blessed with abundant water resources, even by global standards.
However, when it comes to kamaboko-making, not just any water will do.
The significance of Hamacho, Odawara, lies in the fact that we can obtain naturally mineral-rich water, with the perfect pH for guchi fish, without adding or removing anything.

Moderately hard water, rich in calcium, is particularly suited for kamaboko production.
Moreover, the shallow well water in Hamacho, Odawara, which is close to the coast, contains trace minerals from seawater. This combination of calcium, magnesium, and other minerals contributes to the creation of delicious kamaboko.

The natural state of water is something that we, as humans, cannot control.
We believe that the geographical blessing of being able to access this pure water in Hamacho, Odawara, where Yamajou Kamaboko Shop is located, is truly a gift from nature.

The reason for the deliciousness of Yamajou Kamaboko, and why Odawara kamaboko can only be made in Odawara, lies in the unique characteristics of this water that can only be found in this region.
That is why we at Yamajou Kamaboko are so committed to the water of Hamacho, Odawara.