Is it Christmas?
One explenation could be: People like to buy Cognac for Christmas, assumingly as a present: The famous french brandy is considered to be something special, valuable and a product that is to be consumed with pleasure and time.
If you look at the graph below, you see that every year the “cognac” searches in google go up. The date: 10th to 17th of December, just before Christmas.
Is it New Year’s?
Another explenation could be: People don’t buy it for Christmas but for New Year’s eve.
Sitting in front of the fireplace, it’s cold outside, having a cognac in your free time, during holidays.
Probably the reason why wordwide consumers look for Cognac in this period is a combination of the three listed assumptions. The graph above somehow could also be mean, that a huge chunk of cognac buyers might only buy a bottle once a year; for Christmas.
The image of “grand father’s old drink” is somehow confirmed with this. But if we look at other countries, we also see google search activity during the summer – this might be linked to usage of Cognac in cocktails.
Unfortunately we do not know the sales figures for the different seasons; that would be something highly interesting.