From the enticing aroma of the turkey in the oven to the “whoosh’” of the flames as the brandy-soaked pudding comes alight, Christmas is a wonderful time for the senses. But have you ever considered the science behind our best-loved festive traditions? Here is one of my seven food and flammable favourites: The others can be found on this website.
The more obviously flammable part of the Christmas meal is the Christmas pudding. Brandy is normally used to provide the fuel: ethanol. The ethanol molecule contains some oxygen, so it burns with a clear, hot, blue flame, unlike the hydrocarbons in candle wax, which give a yellow flame.
Over half the brandy is actually water, so some of the heat from the fire is used to evaporate the water, which stops the pudding from getting too hot and burning to a crisp, so it keeps that moist, chewable consistency.