Pan de cristal

Four airy loaves from a very wet dough

Pan de cristal, also called glass bread, is a Catalan-associated wheat bread with a thin crust and a very open interior. This King Arthur Baking version makes four medium loaves, each about 5 by 7 inches. Its dough begins unusually slack: the formula uses equal weights of water and bread flour. Repeated folds build enough structure to divide and bake it without extensive kneading. The formula here follows that publisher's tested version, rather than presenting one universal Catalan method.

The ingredient list is short: water, bread flour, instant yeast and table salt, plus olive oil for the resting dish and extra flour for handling. That last flour is specified as needed rather than measured. Do not treat it as a fixed part of the dough hydration; it is used on the bench and surface during division. The source's weights are the clearest guide for the main formula.

A regional association, not an origin story

King Arthur Baking describes pan de cristal as a variation of a traditional loaf from Catalonia in Spain. Its introduction gives no dated evidence or specific locality, so the recipe's place record stays at regional precision and its earliest period remains unknown. The publisher's recipe is a contemporary US adaptation with its own measured flour, timing and equipment choices. It should not be used to fill gaps in the bread's broader history.

The publisher's author describes developing this version by changing the dough strength, fold count, fermentation and final rise across several bakes. That account explains why this particular formula uses bread flour and a short series of folds. It documents recipe development, not a historical chronology of pan de cristal in Catalonia.

Why the dough needs folds

At 100 percent hydration by flour weight, this mixture initially feels more like a thick batter than a conventional kneaded dough. The recipe relies on bread flour's gluten-forming capacity and time between folds. The King Arthur author reports that the dough becomes smoother and stronger through fermentation and repeated handling; the final structure is meant to retain gas while remaining loose enough to open into large cells.

A bowl fold gathers dough from the sides toward the center. A coil fold lifts the dough underneath and lets it fold over itself. Wet hands help with the sticky mass. The recipe uses several rest periods, with folds becoming fewer as the dough gains strength. The source's test notes say an extra fold is not always helpful: over-strengthening can reduce the open crumb. That is a texture observation from the publisher's bakes, not a guaranteed result for every flour or kitchen.

Mixing, resting and folding

Mix the water, bread flour, yeast and salt in a medium bowl until evenly combined. The publisher prefers weighing the flour. Measure the center dough temperature after mixing: the published target is 74–76°F (23–24°C). If it is below 72°F (22°C), the recipe directs the baker to move the dish to a warmer place. Oil a 2-quart (10-by-7-inch) rectangular dish, or an 8- or 9-inch square dish, and transfer the dough there. Cover for a 20-minute rest.

Use wet hands for the first bowl fold, lifting dough from the sides into the center eight to twelve times. Cover and rest 20 minutes. Make a coil fold, turn the dish a quarter turn, and repeat until the dough begins to resist stretching. Cover and rest another 20 minutes. Repeat the coil fold and rest twice more; the third set uses only two or three folds. For the last set use one or two folds only if the dough still needs strength. Then cover and rest about 80 minutes. The source allows skipping that last fold when the dough already feels strong.

Dividing and baking two loaves at a time

Turn the dough gently onto a heavily floured surface. Dust its top and cut it into four pieces with a bench knife or sharp knife, taking care not to press out the gas. Place two portions on parchment with space between them. Leave the loaves uncovered at room temperature for two hours. The publisher says to look for several large bubbles on the surface and a light, airy feel; it also notes that proofing can vary with ambient conditions.

While the loaves proof, preheat the oven with a baking stone or steel on a lower rack at 475°F (246°C) for one hour. Slide two loaves, still on parchment, onto the hot surface. Bake for 15 minutes, then move them directly to the upper rack for another 13–15 minutes. Repeat with the other two loaves and cool fully on a rack. The page header lists a 27–28 minute bake. Its instructions say 15 minutes on the stone or steel, then 13–15 minutes on the upper rack, and state a total of 27–30 minutes; the step durations add to 28–30 minutes. This is an internal timing discrepancy in the source, so follow the staged instruction and check the loaf as it bakes. It also lists a preheated cast-iron pan or oven-safe skillet as an alternative. A baking sheet may work, but the publisher warns that it can warp when heated empty.

Planning, equipment and batch limits

Allow the publisher's stated six-hour total schedule. It includes multiple 20-minute rests, a long covered rest, a two-hour uncovered proof and an hour to heat the oven and stone or steel. The oven preheats during the proof, so those tasks overlap. The published sample timeline starts mixing at noon and places the bread in the oven at 5 p.m.; oven loads and cooling extend the work around that outline. Active time is listed as 40 minutes, and the source divides the four loaves between two oven loads.

The method uses a medium bowl, a covered dish, a digital thermometer, a bench knife or sharp knife, parchment, a baking stone or steel (or one of the listed alternatives), an oven and a cooling rack. The resting dish is not used to bake the bread. The high heat creates a practical parchment concern: the publisher notes that parchment edges can char above 450°F (232°C), so trim excess and keep an eye on exposed paper. Use parchment only within its manufacturer's temperature guidance.

The four-loaf batch is the only documented scale here. The source does not test doubling the formula or changing the loaf size. A larger batch could change fold handling and oven scheduling; no adjustment is supplied. The rating reflects the wet dough, repeated timed folds, delicate division, hot baking surface and two-load schedule. It does not describe a special microbiological hazard.

Crust, crumb and storage

The bread is known for a crisp crust and large irregular holes. The high water ratio and gentle handling help keep the dough open, while the hot stone or steel gives the loaves a strong initial heat. The publisher reports that the crust softens and the bread stales quickly because it has a high crust-to-crumb ratio. For quality, it suggests reheating uncovered in a preheated 400°F (204°C) oven for about 8–10 minutes.

King Arthur Baking advises wrapping the bread loosely and storing it at room temperature for several days, or freezing it for longer storage. That is publisher quality advice, not a validated safe-storage limit. This page does not infer a shelf-life deadline or food-safety control from the recommendation. Use clean handling and discard bread with visible spoilage.

A documented modern restaurant bread

Ariadna Boada's 2012 report places pa de vidre in Barcelona's modern restaurant trade. It describes Jordi Nomen's Concept Pa bakery in the Zona Franca making bread for restaurant customers, par-baking and freezing it for distribution. The report connects its service with pa amb tomàquet and ham; it does not publish the commercial formula.

In a 2021 interview, Nomen recalled presenting his bread at San Sebastián Gastronomika in autumn 2008 and developing it after a mixing error left excess water in dough. That is an attributed maker's recollection, rather than a verified first invention date for every bread called pan de cristal. It adds modern production history to the Catalan association without making King Arthur's four-loaf home recipe a reproduction of Concept Pa's process.