Black wheat – blé noir – is a common French term for buckwheat flour or farine de sarrasin, to give it its proper French name. Actually, blé noir and buckwheat are both misnomers since the plant is unrelated to wheat and is botanically closer to rhubarb or sorrel. The flour ground from the grain/seed is greyish with black flecks (hence the French nickname) and has the added benefit of being gluten free.
According to Larousse Gastromonique, until the end of the 19th century, buckwheat was one of the staple foods of Brittany and southern Normandy. It was a crop particularly adaptable to marginal, dry areas unsuited for wheat. In the traditional cuisine of Brittany, buckwheat flour is used in their signature savory-filled crêpes called galettes which we make on Pancake Day (more on that later!). Bretons also make both sweet and savory cakes and biscuits with buckwheat flour.
Since I had the greater part of a bag of buckwheat flour left over from holiday blini making, I thought I’d experiment with making a traditional Breton gâteau. See the Notes on the results of the experiment below the recipe.
Gâteau Breton au blé noir (Breton buckwheat cake)
Many modern versions of Gâteau Breton substitute some of the buckwheat for wheat or other flours, while others cut out the buckwheat altogether and just use wheat flour. Baking only with buckwheat harks back to earlier days and produces a gluten free cake with a unique flavor. The cake is supposed to be a cross between shortbread and pound cake – slightly crumbly, but dense and still moist in the center.
- 1/2 cup butter (1 stick)
- 3/4 cup sugar
- 1 teaspoon vanilla
- 5 egg yolks
- 1-1/4 cup buckwheat flour
- 1 teaspoon baking powder
- 1/2 teaspoon sea salt
- 1 egg
Preheat oven to 325 degrees F. Prepare a 8 inch spring form pan by lining the bottom with baking parchment, lightly buttering the inside and dusting with a little buckwheat flour.
In a mixer, beat the butter and sugar until very smooth and creamy. Add the vanilla. Then, add one egg yolk at a time, making sure each become incorporated. In a separate bowl, mix the flour, baking powder and salt together. Add the flour to the buttery mixture and mix just until it is fully incorporated. Do not over mix.
Put the dough in the prepared pan; it will be stiff. Smooth and press the dough to evenly cover the bottom of the pan. Brush beaten egg over the top, smoothing it. With the tines of a fork, score diagonal lines in the top of the cake. This is the traditional way of decorating the cake, but also serves a purpose in preventing the cake from splitting as it rises.
Bake for 50 to 55 minutes. Remove and let cool on rack for ten minutes before removing it from the tin. The scored lines will have smoothed out, but will still be visible. Cool completely before cutting and serving. It is one of those cakes that is still good (and even improves) in a day or two.
Note on the results: The flavor of the cake is nutty with chocolaty overtones. It is quite strong a flavor and I think that some modern palates might appreciate substituting some of the buckwheat with almond meal or wheat four. David Lebovitz, in his wonderful cookbook, The Sweet Life in Paris, has good balance of flours in his recipe for “Breton Buckwheat Cake with Fleur de Sel”. The cake would also be good with cocoa added to bump up the chocolate flavor, or served with a seasonal fruit compote.