Combine yeast and warm water, stirring a little to dissolve yeast.
Let sit about 10 minutes.
Add 1/2 of flour; add water and honey; whisk until smooth.
Cover bowl and let stand 1 1/2 hours.
Combine remaining flour with butter, and flatten butter pieces.
Pour yeast batter into flour mixture; fold together with spatula; just moisten flour without breaking butter pieces.
Turn dough onto lightly floured surface.
Pat dough down and roll into a 18" x 12" rectangle; if too sticky, sprinkle with flour.
Use a metal spatula to fold 1/3 of dough toward center; then fold from other side, 1/3 of dough over first 1/3.
Lift folded dough off work surface, and scrape surface clean.
Sprinkle work area with flour and repeat, rolling and folding 3 more times.
Dough must be hard; if not, freeze for 45 minutes.
Pat dough into rectangle.
Cut into parts, 1 part for each 4 croissants.
For instance, for 24 croissants: cut in 1/2 lengthwise, then cut each half into 3 pieces, for a total of 6 (4x6=24).
Work with one piece at a time, holding others in refrigerator until ready to use.
Roll each piece individually into 5 1/2" x 14" rectangles.
Cut into two 5 1/2" x 7" pieces.
Cut each piece diagonally to form 4 triangles; roll from wide end to point.
Place on ungreased cookie sheets.
Curve ends to crescent shape.
Beat egg with water; brush croissants with this and set them aside 1 hour.
Reglaze with egg/water mixture.
Bake at 375 degrees until puffed and brown.
Let cool slightly and serve.