Why TOST Loves the Water in Mid Wales

At TOST, we know that water makes up over 98% of your coffee and the right minerals can bring out the best in every cup. Specialty coffee guidelines, suggest the “ideal” water for coffee contains:

• Magnesium: 15–25 mg/L

• Calcium: 10–30 mg/L

• Total hardness: 50–100 mg/L

• Alkalinity: 30–60 mg/L

These minerals help highlight sweetness, clarity, and bright, vibrant flavours.

Here in Mid Wales, we’re lucky. Our upland springs and reservoirs naturally provide water that is clean, balanced, and positively suited to specialty coffee. It’s soft enough to preserve delicate flavours, yet naturally mineral-rich enough to support a full-bodied, satisfying extraction.

We’ve done extensive in-house taste testing, comparing our local water with other mineral profiles. The result? The difference is minimal — far smaller than the impact of beans, roast, freshness, and precise extraction.

That’s why at TOST, we make a conscious choice: we let the natural qualities of Mid Wales water shine. It’s one of the reasons our coffee tastes so vibrant, clean, and amazingly balanced.