Place the flour in bowl of electric mixer. make a well in the centre and add the yeast and milk.
Sprinkle over a little flour and wait a few minutes for bubbles to appear. This means you yeast is active.
Start the mixer with the dough hook attached and slowly add the water and melted butter and combine.
Add the salt and sugar.
Keep mixing until the dough becomes very sticky. In dry weather you may need to add more water.
Continue until the dough is very elastic. This could be up to 10 minutes of mixing.
Place in an oiled bowl and cover with plastic wrap. Allow to proof until 1½ times it's size (about 45 minutes to 1 hour) then refrigerate overnight.
Roll the dough to an oblong shape three times longer and it is wide.
Spread ½ the softened butter over the centre third part.
Fold the top third over the butter then spread remaining butter over the folded section.
Fold the bottom third over the top. At this point I covered it in plastic and placed it in the freezer for ½ hour.
Take the dough and place it so that the folded seams are at the sides.
Roll out the pastry again to form a large oblong sheet and fold it in three.
Cover in plastic wrap and refrigerate for 30 minutes in winter and 45 minutes in summer.
This is one "turn". Repeat this procedure 3 times - a total of 4 "turns". Remember to keep everything very cold. If butter oozes through sprinkle with flour to seal and refrigerate.
Preheat the oven to 220C and line a baking tray with greaseproof paper.
Roll the dough into a large 3-4mm thick rectangle.
Trim the edges, then cut out 10cm wide by 20cm deep triangles.
Make a small slit in the base of each triangle which will allow the dough to stretch when rolled. So starting at the base roll the croissants and shape into a crescent.
You can now let them rise for at room temperature until doubled. This could take 30 minutes to a little over and hour. Or refrigerate them overnight as I did. At this point they can also be frozen to be baked at a later date.
When risen brush with egg wash and bake for 10 minutes then lower the temperate to 350ºF/180ºC and bake for a further 8 minutes. Do not open the door while baking.