In a continuation of my musing on Christmas food (see also mince pies and marzipan), today I write about the Yule Log. If you’re not familiar, this is a cake - usually a Swiss-roll type sponge - covered in chocolate icing or ganache to look like wood.

Versions are popular across Europe (in French it is the bûche de Noël). My mother made them sometimes when I was a child, and even had a tiny model robin to sit on the cake as a decoration.

As a dessert it’s very nice, makes a change from the denser fruitcake options. Indeed it’s unusual in Christmas sweets for not having any dried fruit in sight! So how did it get onto the Christmas table?

“Yule” refers to a winter festival of the pre-Christian Germanic groups of Europe. The “yule log” was once the choice log fallen from the woods to be burned during the winter festival.

However, it’s not necessarily a straight line from someone worshipping Odin hundreds of years ago, and someone rolling up a sponge cake today. After the arrival of Christianity in Europe, and the focus of the winter festival shifted to the birth of Jesus, some older customs lingered. How much they really lingered, is a different question. The invention of tradition since the 1700s has led to the “rediscovery” or recreation of older pagan ideas (see also the rise of Druidism in Britain in the twentieth century, and the creation of “wicca” with its mythos of being an ancient faith).

Of course, in a place dependent on wood for light and warmth, choosing a primo log to burn makes a lot of sense, beyond any spiritual significance.

The time that the term Yule Log starts moving to referring to cakes rather than wood, is the nineteenth century. This is the point where more people were able to use coal for heating (or had oil or gas central heating), and kitchen technology was changing too.

The older Christmas desserts, like fruit cake and pudding, could be steamed or baked slowly in a box oven over coals. They could be made well ahead. They were stirred with a wooden spoon.

Sponge cake was a very different matter. To bake one successfully required a more controlled heat in an oven (which modern stoves were better able to provide). They also required a lot of beating of eggs, with whipped whites providing the raising for the cake.

Enter a key piece of kitchen technology: the egg beater.

They start showing up in the 1850s, and various versions (moving onto something closer to a stand mixer) are patented over the succeeding decades. Cranking one can still be hard work, but produces an aerated batter.

Recipe books (another flourishing nineteenth century industry, catering to a rising middle class) were quickly full of sponge-based desserts, and other things that require lots of beating (the chemical raising agent, baking powder, also started to be widely available commercially in the second half of the nineteenth century).

More desserts were possible because sugar was also more affordable - through the mechanisation of cane harvesting, and the development of sugar beets (beets were the source of 50% of the world’s sugar production by 1880, and dominated the market in Europe). Fancy dishes like meringues and sponges were no longer the province of patisserie chefs, but could be made easily in the middle-class home.

Earlier this year, John Kelly wrote in the Washington Post that few people today own a rotary beater. Modern cooks use an electric mixer. That doesn’t mean they don’t have fans: one collector/devotee has written an entire book about them.

In the twentieth century came box cake mixes, and pre-made icing, additional ways for home cooks to prepare cakes with less effort (Betty Crocker even have instructions to make a yule log with their products).

But this is why we have a sponge cake, that looks like a tree, as part of a Christian festival.