A high quality baker’s couche is professional grade 100% flax linen that is natural, untreated and unbleached. It is used to support dough, especially baguette, during proofing. Linen is durable, flexible and light, and is the best material to proof bread.
For baguettes placing the dough between the folds maintains its shape, absorbs the excess moisture and prevents them from sticking to each other as they increase in size. Only a 100% linen cloth can do all this and release the dough without sticking.
It has a wicking property that absorbs a little of the moisture on the surface of the dough without drying it out thus gives baguette a chewy, thin, crunchy crust. The couche should have durable seams on all four edges to prevent fraying over time.