The all-powerful GST Council on Friday more than doubled the tax on caffeinated beverages to 40 per cent and slashed the rate on hotel room tariffs. Briefing reporters after a meeting of the panel, Finance Minister Nirmala Sitharaman said the GST on caffeinated beverages has been hiked to 28 per cent plus additional cess of 12 per cent as against the current rate of 18 per cent.