I've only had pumpernickel once - at the time I described it as corkboard soaked in treacle. But that was half a lifetime ago. I might like it now¹.

- an h2g2 Researcher

Pumpernickel is a special dark German bread made of coarsely ground rye and water. Unlike with other rye bread, no sourdough is added. To give you an idea of the procedure, here is roughly how it is done the traditional way: part of the dough is mixed with hot water and left to ferment for about 12 hours. This mixture is called the Brühstück (literally: a piece of broth).
The rest of the flour is added, the whole mixture is kneaded and put into a lidded tin which is put into the oven at low heat (~ 120°C/250°F) where it stays for another 12 to 16 hours. The oven has to contain steam at all times. You could say that the bread is steamed, rather than baked.

Our ancestors needed to have quite some skills and experience for the successful production of pumpernickel (or any other bread for that matter).
Without a thermometer it wasn't easy to decide whether the oven had the correct heat. One test was, to take a pinch of flour and throw it into the oven. If the flour turned black, the oven was too hot, if it remained white, the oven was too cold, if it turned brown, the oven had the right temperature.

It's probably not surprising that the size of the oven determined the number of loaves which could be baked in one go. A smaller oven allowed for fewer, smaller loaves than a large oven. However, the small loaves didn't need so many hours to be baked; they could be ready after about seven hours.

Why is it so black?

Once the dough is in the oven and submitted to the heat, something called the 'Maillard reaction' takes place. In short: the starch of the rye is transformed into sugar which reacts with the proteins. The sugar caramelises and gives the bread its dark brown to nearly black colour as well as its specific flavour. Another effect of this special steaming procedure is that pumpernickel is pasteurised which explains why it can be conserved for so long: sealed appropriately it can be kept for several months (some even claim up to two years if kept in cans). The texture is crumbly and the bread doesn't have a crust.

Nowadays, as 'Time is Money', the process is often shortened by adding sourdough to the flour as a starter, and molasses for the colour. For instance North American pumpernickel has little resemblance to its German 'brother'. Traditional pumpernickel, however, does not contain anything but rye and water.

History

Pumpernickel originates from Westphalia, Germany, but that's about the only thing that's certain. The Westphalians themselves referred to it as grobes Brot (coarse bread) or schwarzes Brot (black bread), and it was only outside Westphalia that it was called pumpernickel.

It possibly dates back to the 15th Century but it wasn't until after the Thirty Years' War (1618 - 1648) that it was called pumpernickel, when HJ Christoffel von Grimmelshausen mentioned it in his book Der abenteuerliche Simplicissimus Teutsch (The adventurous Simplicissimus German) in 1668.

What is the meaning of the name?

There is no certain explanation, but various attempts at an etymology have been made: some of them amusing, some likely. Here are some possible explanations:

The OED gives the origin as: originally meaning 'lout, bumpkin'. This is probably close to the truth, as you'll see a bit further down.

A Pumper is an old German word for a fart. Those among you who have tried pumpernickel will know that it does indeed have this effect on the digestive system.

Nickel has various meanings. Apart from the most obvious one, namely the chemical element (Ni) which is of no relevance here, it was the name for an old German coin, probably comparable to the farthing, so you could get a fart for a nickel. Others say it derives from Nicklas (Nicolas), so pumpernickel would be a farting Nicklas or a lout - which brings us back to the OED's explanation. Yet other meanings are given as nickel being an imp or a wicked child. Regionally, it also meant a loner or a fogey.

In various witch trials of the time, Pompernickel is documented as the name for the devil; the possible connection here being the colour (black) of the bread, and the farting it causes. In England, 'Old Nick' is an expression for the devil, and in Germany, he is known as De Belsenickel regionally.

An anecdote which is still known today and was already mentioned in the Oeconomische Encyclopädie (Economic Encyclopaedia) by Johann Georg Krünitz in 1779, claims that either Napoleon Bonaparte himself or one of his soldiers refused the bread he was offered in a German inn with either the words: C'est bon pour Nickel (or Nicole) or C'est pain pour Nickel/Nicole², with Nickel/Nicole being the name of Napoleon's horse.

Although all these meanings seem to imply that the name 'Pumpernickel' was a pejorative for the bread³, you will nowadays find a huge variety of recipes using pumpernickel. Pumpernickel slices are always thin. They are an ideal base for canapées amongst others.

However, you can always just have it instead of other bread, and it is possibly still the bread of choice for a German to take on a holiday abroad to prevent constipation.

Pumpernickel Trivia

• The radio DJ Chris Howland became famous (in Germany) under the name of Heinrich Pumpernickel, a term he apparently coined himself during one of his very popular radio shows.
• Actress and singer Doris Day topped the charts in 1952 with her hit 'Pumpernickel'.
• Pumpernickel as a reason to want to be German is mentioned in Blackadder Goes Forth (series four, episode five: 'General Hospital').
• There is a Loony Tunes Cartoon called The Scarlet Pumpernickel.
• Marlene Dietrich is said to have taken innumerous slices of pumpernickel whenever she went to a restaurant serving borscht.