Dissolve yeast in one-half cup of lukewarm milk, add salt, and a tablespoon of sugar and let it rise. Then make a soft dough of sifted flour and as much milk as is required to work it, about two cups; add the yeast, one-half cup of sugar, the butter dissolved in the warm milk, the grated peel, raisins, and eggs. Work this dough perfectly smooth with the palm of your hand, adding more flour if necessary. It is hardly possible to tell the exact amount of flour to use; experience will teach you when you have added enough. Different brands of flour vary, some being drier than others. Work the dough as directed, set it aside covered until it is double the bulk of the original piece of dough. Then work again and divide the dough into two parts, and divide each of the pieces of dough into three parts. Work the six pieces of dough thoroughly and then roll each piece into a long strand; three of which are to be longer than the other three. Braid the three long strands into one braid (should be thicker in the centre than at the end), and braid the shorter strands into one braid and lay it on, top of the long braid, pressing the ends together. Butter a long baking-pan, lift the barches into the pan and set in a warm place to rise again for about one-half hour. Then brush the top with beaten egg and sprinkle poppy seed all over the top. Bake in a moderate oven one hour.