Combine yeast and warm water, stirring a little to dissolve yeast. Let sit about 10 minutes. Add half of flour; add water and honey; whisk until smooth. Cover bowl and let stand 1.5 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 46 cm x 30 cm rectangle; if too sticky, sprinkle with flour. Use a metal spatula to fold one third of dough toward center; then fold from other side, one third of dough over first 0.33333333333333. 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 half lengthwise, then cut each half into 3 pieces, for a total of 6 (4x6$). Work with one piece at a time, holding others in refrigerator until ready to use. Roll each piece individually into 14 cm x 36 cm rectangles. Cut into two 14 cm x 18 cm 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.