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.

IceVolumeSurface
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 55 mm ice sphere has about 95 cm² of surface; the same 87 cm³ of ice as 2.5 cm cubes has about 209 cm²
The same 87 cm³ of ice: the sphere has less than half the surface of the cubes.

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 XIMIVA YH1800 and YH1600 sphere ice makers side by side
YH1800 (left): 55 mm spheres. YH1600 (right): 55 or 50 mm.

The YH1800 makes four 55 mm spheres per cycle. The YH1600 offers 55 and 50 mm.