Brioche

The temperature of the butter is one of the most critical variables in brioche. Cold butter (16 to 18°C) that is pliable but not greasy emulsifies into the dough gradually, coating the gluten threads and fat globules in a stable emulsion. This produces the characteristic smooth, glossy, slightly sticky dough with an even, feathery crumb structure. Warm or softened butter (22°C or above) is too fluid — it causes the water and fat phases to separate, breaking the emulsion and producing a greasy, slack dough that cannot hold its structure. If the dough becomes warm and greasy during butter incorporation, refrigerate the bowl for 10 to 15 minutes before continuing. Many professional brioche recipes specify the dough temperature must not exceed 23°C during mixing.

Yes, but it is extremely demanding by hand and Julia Child — who made it regularly — described the process as requiring determination and strong wrists. The technique is called fraisage: stretch the dough forward across the counter with the heel of your hand, fold it back on itself, rotate 90 degrees, and repeat. The butter is incorporated after the dough has been hand-kneaded for 10 to 15 minutes, then the process continues for another 20 minutes until the butter is absorbed and the dough is smooth. It helps to work on a marble counter or cold surface. The result is genuine and sometimes preferred by purists who argue that hand kneading generates less heat than a machine, keeping the butter at the ideal temperature throughout.

The windowpane test is a simple way to verify that gluten has developed sufficiently. Pinch off a small piece of dough (about the size of a walnut), stretch it gently with both hands from the centre outward, working gradually toward the edges. If the dough can be stretched into a thin, nearly translucent membrane without tearing — thin enough to see light through — the gluten structure is developed. If it tears before becoming translucent, the dough needs more kneading. For brioche, the windowpane test should be performed twice: after the initial knead (before butter is added) to confirm the base gluten structure, and again after all butter has been incorporated to confirm the structure has held together through the butter addition.

Brioche improves dramatically with age in a secondary application. Fresh brioche is wonderful eaten plain or with jam, but brioche that is one to three days old — when the crumb has firmed slightly from the butter setting as it cools — makes incomparably good French toast: its density means it absorbs the egg custard deeply without falling apart, and the butter content creates a self-basting effect in the pan. It also makes exceptional bread pudding, croque monsieur, and pain perdu. Truly stale brioche can be blitzed into breadcrumbs — the richest, most flavourful breadcrumbs available for crumbing escalopes or finishing gratins.

Both brioche and challah are enriched, braided egg breads with a long history, but they are distinct in several important ways. Challah is a Jewish ceremonial bread in which all fat comes from eggs and oil — no butter or dairy is used, making it kosher and pareve (neither meat nor dairy). It has a slightly firmer, more bread-like crumb with a distinct eggy flavour. Brioche is a French viennoiserie in which a very substantial quantity of butter is added to the dough after the initial knead — butter typically constitutes 40 to 50% of the flour weight. This makes the crumb dramatically softer, richer, and more tender, with a pronounced dairy quality. Brioche also has a thinner, more shatteringly crisp crust than challah's thick, chewy exterior.