Why Put Serum-Grade Ingredients in a Lotion? Decorté’s “Black Koji Ferment Filtrate” Redefines the New Standard in Daily Anti-Aging Care

When you hear the word 'fermentation,' you likely think of something good for your body. The cosmetics industry is no different, where 'ferment filtrate' is a buzzworthy ingredient. This fall, Decorté is capturing the spotlight with the launch of its original “Black Koji Ferment Filtrate,” a breakthrough ingredient developed through years of research.'

But why exactly is fermentation beneficial for the skin? And of all the fermented ingredients out there, why choose 'black koji' now? We spoke in detail with Masahiro Taira, a senior researcher at the KOSÉ Research Institute in charge of products for Decorté, to uncover the true potential of this new ingredient, which emerged from their proprietary aging research.

So, Why is Fermentation Good for Your Skin?

We know fermentation has a healthy reputation for our bodies and skin, but what exactly is it?

"Fermentation is the process where microorganisms like koji mold, lactic acid bacteria, or yeast transform a substance into something beneficial for humans. If the change results in something harmful, we call it spoilage.

Miso and soy sauce are classic examples. Fermenting the base ingredients enhances their umami flavor, nutritional value, and preservation. The Japanese have been mastering the art of creating diverse fermented foods for centuries, and it's a technology we can be truly proud of.

Moreover, the compounds created through fermentation are expected to guide the skin toward a more active state. In an experiment we conducted at our company, applying ferment filtrate to cells confirmed an increase in cellular activity, regardless of age.

On the other hand, our proprietary anti-aging[1] research has shown that the number of active cells responsible for skin firmness and elasticity decreases with age. This is why we have such high hopes for the properties of fermentation and are actively researching its many possibilities."

With so many ferment filtrates on the market, Taira explains that developing one that met Decorté's ideal standards was a journey filled with challenges.

"While we knew ferment filtrates were beneficial for the skin, our previous research faced hurdles. Sometimes the balance of components wasn't quite right, or the unique smell of the raw materials made it difficult to use high concentrations. To overcome all of these challenges, we set out four key objectives: (1) Be rich in beneficial components, (2) deliver visible effects on the skin, (3) allow for high-concentration formulation, and (4) minimize fermentation odor while maintaining a pleasant texture. With these ideals in mind, we began the development of a completely new and ideal ferment filtrate."

To achieve this, they took inspiration from *amazake*, a sweet fermented rice drink often called a 'drinkable IV drip,' and decided on koji and rice as the base materials. Thus began a painstaking search for the ideal combination among countless varieties of koji and rice.

"We collaborated with fermentation specialists to first examine the type of fungus. From a long list of candidates, we landed on black koji mold, known for producing an abundance of organic acids that are beneficial for the skin. For the rice, we chose brown rice, which lets us use the whole grain, including the nutrient-rich bran. Specifically, we selected the 'Awayuki Komachi' variety, which is highly absorbent and ideal for fermentation."

Even after discovering the perfect combination of ingredients and bacteria, the development process was incredibly challenging. The biggest hurdle, they say, was the "smell."

"Because black koji mold is a living organism, controlling the fermentation process was extremely difficult. Trying to boost its nutritional value would sometimes result in an unpleasant odor, and even when we succeeded, we couldn't consistently replicate the same quality. We failed countless times during the manufacturing process, refining our approach with each attempt."

Through this painstaking process of trial and error, they created their proprietary, naturally derived ingredient: "Black Koji Ferment Filtrate (KUROKOJI®)." This finished ferment is packed with over 470 different components, including 39 peptides, 18 amino acids, and 353 organic acids.

While packed with this diverse array of components, the Black Koji Ferment Filtrate not only delivers reliable hydration but has also been found to have a skin-smoothing effect. It's so high-performance that it could stand alone as a serum, making it a powerful secret weapon for mature skin that might be tempted to give up on anti-aging care[1].

Why a Lotion and Not a Serum?

The new "Youth Power Essence Lotion" features a high concentration of this powerful Black Koji Ferment Filtrate—a whopping 62%.

There's a specific reason why they chose to develop it as a lotion rather than a thick, serum-like formula.

"The Black Koji Ferment Filtrate can replace the water that typically forms the base of cosmetics. We believed that by formulating it as a high-concentration lotion, which has a high water content, we could maximize its benefits. Plus, lotions are a daily staple for most people. By creating a lotion, we wanted our customers to easily incorporate it into their daily skincare routine and experience its powerful effects."

The packaging even explicitly states "." The goal was to clearly communicate that this is a lotion that also packs the function and high efficacy of a serum. It garnered rave reviews from media insiders even before its public launch. When I tried it myself, I was impressed. It had the fresh, instantly absorbing feel of a lotion, yet it left my skin with the firm, supple feeling you'd expect from a high-performance serum.Decorté's Vision for the Future of Anti-Aging Care[1]Decorté continues to push the boundaries of anti-aging care[1], backed by cutting-edge research. We asked them for their take on the concept of anti-aging."Anti-aging care[1] is an eternal theme in dermatology, with research being conducted all over the world. At Decorté, we don't believe in fighting against age. Instead, we champion a beauty that transcends age itself.The signs of aging are a testament to a life lived. At the same time, it's completely natural to want to feel youthful. When your skin feels firm and radiant, it can brighten your whole outlook. At Decorté, we aim to be a partner in our customers' shining lives, supporting them in achieving their desired look and feel through our products and research."The "Youth Power Essence Lotion," featuring the Black Koji Ferment Filtrate, launched on September 16. In just over 10 days, sales hit 153% of the initial forecast, setting a new all-time record for a lotion in the brand's history. We invite you to experience this ideal anti-aging[1] lotion, the result of Decorté's uncompromising pursuit of excellence.