Borjomi vs. Istisu: Two Waters, One Caucasus

Same mountains. Different origins. Different personalities.

Borjomi is the volcanic classic of Georgia. Istisu is the geothermal treasure of Azerbaijan.

Both are zero-calorie gifts of the Caucasus — shaped by ancient rocks, underground journeys, and the landscapes that surround them.

The best way to choose? Don’t choose.

Taste both, and let the mountains tell their stories.

Born from Different Depths

Borjomi rises from volcanic layers deep beneath Georgia’s Lesser Caucasus. Its signature feature is its exceptionally high bicarbonate content — around 3,900 mg per liter — giving it a bold, salty, slightly alkaline taste. With around 1,550 mg/l sodium, 60 mg/l calcium, and 50 mg/l magnesium, Borjomi is one of the most recognizable mineral waters in the region.

Istisu, meaning “hot water” in Azerbaijani, tells a different story. Emerging from thermal springs in Kalbajar, at an altitude of around 1,600 meters, it is shaped by geothermal activity. Its water comes from a source reaching approximately 58.8°C and is known for its bicarbonate, sodium sulfate profile, as well as trace minerals such as lithium, iodine, and bromine.

What Each Mineral Does

Bicarbonates — your body’s natural antacid. Neutralizes stomach acid, eases heartburn and bloating. The higher the number, the better for digestion.

Sodium — regulates fluid balance and hydration. Great after exercise or heat. High in both waters — not ideal for all-day drinking if you manage blood pressure.

Sulfates — stimulate bile production and gut motility. Good for the liver and fat digestion. Above 600 mg/l they have a mild laxative effect. Best drunk in the morning on an empty stomach.

Chlorides — supports stomach acid production and fluid balance. A background mineral at these levels. Helps proteins digest properly.

Calcium — bones, muscle contractions, nerve signals. Waters above 100 mg/l are a meaningful dietary source — comparable to dairy in bioavailability.

Magnesium — muscle recovery, sleep, stress regulation. Most people are quietly deficient. Absorbs exceptionally well from water.

Who Should Drink Which

Drink Borjomi if you…

• Get heartburn or acid reflux regularly
• Drink a lot of coffee or alcohol
• Want a mineral water you can drink every day
• Care about magnesium (50 mg/l is high for a sparkling water)

Drink Istisu if you…

• Have sluggish digestion or eat heavy, fatty meals
• Want a meaningful calcium source without dairy
• Are doing a liver or digestive reset
• Prefer to drink water with purpose, not habitually

Drink both if you…

• Are generally healthy and curious — rotate them. Borjomi with meals, Istisu in the morning.

About Caucasica

Interested in traveling, researching, volunteering, or collaborating? We’d love to hear from you.

Every journey with Caucasica is designed to benefit both the traveler and the community through local ownership, regenerative practices, cultural respect, accessibility, and authentic human connection.

We create immersive 1-3 day experiences across Azerbaijan, connecting travelers with family homes, regional gastronomy, wellness traditions, artisans, nature, and the stories that rarely appear in guidebooks.

Beyond travel, we collaborate with academics, universities, researchers, exchange students, volunteers, and local communities who share our commitment to regenerative tourism, cultural preservation, and sustainable regional development.

We believe tourism should not simply consume places — it should strengthen them.

Discover Azerbaijan. Contribute to its future.