Windowpane test

The windowpane test tells you if you have kneaded a bread dough enough. You stretch a small piece of dough between your fingers until it is very thin. If it stretches so thin that light shows through, like a window, without tearing, the gluten is well developed and the dough is ready to rise.

How to do it

1. Pinch off a piece of dough about the size of a walnut.
2. Roll it into a ball and flatten it a little.
3. Hold it with the fingers of both hands.
4. Gently pull and turn it, stretching it out in all directions, a little at a time.
5. Hold it up to a light.

How to tell it is done

• Passes: the dough stretches into a thin, see-through sheet. If it tears, the hole has smooth, round edges.
• Fails: it tears quickly with ragged edges before it gets thin. Knead for 2 to 3 minutes more and try again.

Let the piece you tested rest on top of the dough, and it will join back in.

Why it works

Gluten forms as proteins in flour link up with water and are stretched by kneading. A dough with weak gluten has short, broken strands, so it rips. Well developed gluten forms long, stretchy sheets that can thin out a lot without breaking. Those sheets trap gas, so passing the test means the dough can rise well.

Common mistakes

• Pulling too fast. Even a good dough tears. Stretch slowly.
• Testing right after mixing a dough with an autolyse or long folds. Gluten keeps forming as the dough rests, so test after a few minutes.
• Expecting every dough to pass. Rye breads, whole wheat doughs with lots of bran, and doughs heavy with butter or seeds may not form a perfect window. Look for a smooth, springy dough instead.
• Over-kneading in a stand mixer while chasing a perfect window. Check every couple of minutes.

In recipes

"Knead until the dough passes the windowpane test" is the usual phrase. Some recipes for rich doughs like brioche ask for a "full windowpane", which takes longer kneading. Many sourdough recipes build strength with folds instead and do not need a full window.