You can knead the dough by hand or in a machine. As always, I use my food processor on low speed and finish off the kneading by hand.
Mix the yeast and the milk in a small bowl. Let it stand for 5 to 10 minutes till frothy. Mix the flour, salt, sugar, and lemon zest in a large bowl. Make a well in the center of the mixture and add the butter, eggs, extracts and dissolved yeast.
Mix in the flour from the sides of the well. Add the water, a little at a time, till a soft, sticky dough forms. Turn the dough out onto a lightly floured work surface. Knead until the dough is smooth, springy, and elastic.
Shape into a round, and place in an oiled bowl, turning it to coat well. Cover loosely and let the dough rise until doubled in size, about 4 hours (See my note above, about rising times). Deflate the dough gently, cover and let it rest for about 10 minutes.
Divide the dough into two equal pieces and roll each piece into a 16-inch-long rope. Twist the two dough ropes together.
Place the dough rope on a parchment lined baking sheet. Shape it into a ring by bringing the two ends of the rope together. Pinch them well to seal and cover loosely. Let the dough rise again until doubled in size, about 11 ⁄2 hours (once again, a reminder about my note on proofing times).