Why whiskey loves a big ice sphere
It comes down to geometry: for the same amount of ice, a sphere has the least surface. We did the maths.
How fast ice melts depends largely on how much of it touches the drink. More contact means faster heat transfer, faster melting and more dilution.
The numbers
A 55 mm sphere holds about 87 cm³ of ice with about 95 cm² of surface. The same volume in 2.5 cm cubes takes about 5.6 cubes, with roughly 209 cm² of surface.
| Ice | Volume | Surface |
|---|---|---|
| 1 × 55 mm sphere | ≈ 87 cm³ | ≈ 95 cm² |
| 5.6 × 2.5 cm cubes | ≈ 87 cm³ | ≈ 209 cm² |
So for the same amount of ice, the sphere has about 55% less surface. That is why it melts slower and dilutes less.
A few tips
- Choose clearer ice. Fewer bubbles mean denser ice that looks better too.
- Chill the glass first, so the ice is not doing that work.
- Match the size to the glass: 55 mm for a standard tumbler, 50 mm for a smaller rocks glass.
The YH1800 makes four 55 mm spheres per cycle. The YH1600 offers 55 and 50 mm.