Why is it called "blind baking"?

Solution 1:

Most people will say the defining characteristic of "blind-baking" is that you haven't put the pie-filling in when you cook the pastry. You may fill it with small stones, dried peas, etc. to stop the pastry from buckling up, but that's not inherent to the method.

But my source (an experienced "semi-professional" chef) tells me it's highly relevant to note that you don't normally use either elapsed time or sight to decide when it's "done". You use your nose.

Thus "blind" relates to the means of determining baking time.

Solution 2:

I've found an early use of the phrase in A Concise Encyclopaedia of Gastronomy by André Simon, 1952:

Simon was French and I assume wrote this book in French. The clip above includes the following note from the translator (presumably):

N.B.—'Blind' means pricking paste well and filling with tissue paper and beans to stop crust rising

The French phrase for blind baking is cuire à blanc—literally to bake white. My guess is that the English blind resulted simply from its similarity in sound to the French blanc. Perhaps there's even some funny story of mistranslation between a great French pastry chef and his English-speaking protégé.