Our croissant dough is 25% butter, so be sure to use the highest quality you can find. The block of butter used for laminating needs to contain at least 82% fat – a cultured European-style butter is ideal, if you can get it. It will make a world of difference to the flavour of the finished product, as well as to the performance of your dough.
You also need a high-protein bakers flour to get more volume and more pronounced layers. I’ve added spelt for its nutty flavour, and also because it’s more extensible than wheat, which will give you a more elastic dough. If you can’t find spelt flour, use bakers flour.