How much of a variation in percentage of roll in butter can there be for croissants?
The above lists a range from 12.5 to 35% of the weight of the dough.
12% is pretty low and 35% pretty high. I'd say more realistically for a high quality croissant the range would be 20%-30%. I've worked at a few bakeries and all have been 25%.
The standard for most bakeries is about 25% which works well with a sheeter.
At home, where all I have is a rolling pin, I keep the butter percentage at about 30, which seems to work better for me.
Richard Bertinet offers (In his book Crust) a recipe with 40% butter in his croissant.
Andrew Whitley, in his Bread Matters book, goes up to 42%
Obviously, minimising expensive ingredients like butter is good for a commercial bakery.
At home you may wish to treat yourself now and then
Since this post I've tried batches at 20% 25% and 30% the 25 worked the best, but I'm still leaking butter during baking. Ah well, even when you fail at croissants the results are still delicious.
Leaking butter during baking is usually a sign of underproofed croissants
Usually it is, but I've had it happen with a batch of croissants that were definitely overproofed. I'm thinking it may be due to not rolling out thin enough, or if the butter is too cold it will shatter and form lumps in the dough, which then leak.