FAQ Suggestions

MTN WTR is sourced from deep underground aquifers of Mt. Fuji in Narusawa, Yamanashi Prefecture, Japan. It begins as rain and snow that falls high on the mountain (about 1,400–2,700 meters), then moves slowly underground through volcanic rock layers over time. The source region is surrounded by natural forest within Fuji-Hakone-Izu National Park, helping preserve the area’s natural environment

MTN WTR is unique because authentic Japanese spring water is rarely available in the U.S. Japanese spring water is known for a lighter mineral profile (low TDS), which gives MTN WTR its clean, crisp finish. That’s why it pairs so well with quality spirits and delicate dishes—it refreshes without getting in the way.

Sourced from Mt. Fuji’s protected underground aquifers and naturally filtered through volcanic rock for about 50 years, MTN WTR is naturally alkaline at 8.6+ pH with low TDS—no artificial adjustment. And for sparkle lovers, we bring Japan’s 強炭酸 (Kyōtansan / strong carbonation) culture to the U.S. with EXTRA STRONG, featuring 4.0–4.5 volumes of CO₂ for a bold, high-energy fizz.

MTN WTR has a naturally alkaline pH of 8.6+. Mt. Fuji’s basaltic volcanic rock is low in acidity and rich in alkaline minerals. As rain and snow melt and move slowly underground, the water filters through these volcanic layers over decades. Over time, it absorbs those minerals, resulting in a balanced alkaline profile without artificial adjustment.

TDS stands for Total Dissolved Solids. It’s a measure of the minerals dissolved in water—especially calcium and magnesium. Those minerals shape how water tastes and feels. When TDS is high, water can drink “heavier,” with a more mineral-forward finish.

MTN WTR is low TDS because Mt. Fuji’s basaltic volcanic rock is naturally lower in calcium and magnesium. The result is a clean, smooth sip that stays light on the palate. What makes Mt. Fuji water especially distinctive is that it can stay low TDS while also being naturally alkaline (8.6+ pH)—a balance created by the mountain’s geology.

MTN WTR is 100% naturally alkaline. Our 8.6+ pH comes from the water’s long journey through Mt. Fuji’s basaltic volcanic rock over about 50 years. We don’t add anything to change it—no chemicals, no processing, no adjustments.

Approximately 50 years. Rain and snow that fall on Mt. Fuji slowly seep into the mountain’s porous basaltic volcanic rock, then filter through underground volcanic layers over time before emerging at our source in Narusawa. This long journey is what gives MTN WTR its clean clarity and balanced taste.

MTN WTR contains no additives—the only ingredient is water. Any minerals you taste come from the water’s long journey through Mt. Fuji’s volcanic rock over about 50 years. We don’t add minerals, chemicals, or anything to “enhance” the water.

For Sparkling and EXTRA STRONG, the ingredients are just water + carbonation.

We offer two levels of carbonation:

●Sparkling Water: Light, refreshing bubbles for everyday sipping—great on its own, with meals, or for mixing.

●EXTRA STRONG Sparkling Water: 4.0–4.5 volumes of CO₂ for bold, high-energy fizz— inspired by Japan’s 強炭酸 (Kyōtansan / strong carbonation) culture. It stays crisp longer and holds up beautifully with ice and mixers, from citrus and juice to highballs and cocktails—without overpowering the flavors you pair it with.

MTN WTR has a shelf life of 24 months from the production date. The best-by (BB) date is printed on the bottom of each can for your reference.

Our cans use BPA-NI (Non-Intent) liners, which means they are produced without the intentional addition of BPA—similar to BPA-free standards. Our future production runs will continue to use BPA-NI liners.