Ice Ball for your Cognac
Cognac is the world’s most prestigious brandy. It was born in the early 1700s along the Charentes River in the vicinity of the town of Cognac in west central France. The raw, low alcohol and acidic wines of the area were transformed by double distillation and by extensive aging in oak into a product that could withstand sea voyages to markets in Northern Europe and across the oceans.
Cognac industry has been promoting Cognac served in a tall glass diluted with mineral water, sparkling water, club soda, or ginger ale. While some cognac enthusiasts prefer drinking cognac plain or neat, in a very specified tulip shaped or balloon shaped glasses at an ideal temperature of 20-22 degrees Celsius (68-71 F), such shape of the glass allows not just a better grip but also constant heat of the hand transferred to the drink which on the other hand helps release the drink’s aroma. Unlike other drinks cognac is supposed to be an aperitif. Just pour an ounce or two of Cognac into in a tall glass. Add some ice cubes. Then fill the glass with mineral water, sparkling water, club soda, or tonic water if you want a dry mixed drink. Ginger ale can be used for a slightly sweeter hint in the drink. Cognac goes pairs up amazingly well with cigars (for that nutty flavour), and can also enjoyed with ice-creams.

Using Ice Ball
Grande Champagne cognacs possess a light, floral flavour, and work well when served over ice in the summer months. For those cognac lovers who preferred sipping it cold, obviously prefer it on the rocks. But the problem emerges when the drink is about to get finished and the damned ice-cubes makes the whole experience watery that might spoil that smoky and nutty flavour of cognac. Well, the solution to this problem is ‘Ice Ball’.
Ice ball is nothing more than spherical chunks of ice. The advantage it carries over the normal ice-cube is that it keeps the drink cold, yet it melts much slower than individual cubes. The reason behind this is its, low surface area of the ice ball that slows the meltdown process. It is preferred to put ice-ball in a lowball glass instead of taper martini glasses so as to make them rest easily inside.
There are basically three methods to make Ice-balls. One is the Japanese technique of carving an ice ball out of a whole chunk of ice using ice-picks and ice mold. The other easier method is using ice-ball mould (made of either plastic or aluminium). The last option is to shell out some decent buck and get an ice-ball maker.
Reference:
http://www.taisin-ss.co.jp/icemold/english/index.html