• For a very successful batch of croissants, I divide the work over three days and find it easy and calm and a lot less time consuming than I ever imagined. You must read the directions from top to bottom very carefully before starting.

  – Day 1: Make the dough and stick it in the refrigerator. Easy. Bake the baking soda and store it in a clean jelly jar. Even easier. Soften the butter until pliable and beatable and beat in the flour, form the butter block and place it in the refrigerator. – Day 2: Make the puff pastry and do all three turns then leave it in the refrigerator for 24 hours. – Day 3: Roll out the puff pastry, shape the croissants, make the dipping solution and dip, brush with egg wash, dust either with coarse salt, half with sesame seeds, or pearl sugar, or nothing at all. Bake.

Day 1: Prepare the laminated puff pastry (the dough), baked baking soda & butter block

• Have a clean, dry, soft pastry brush handy for brushing flour off of the surface of the dough and in between folding…
• Stir the yeast and 1 tablespoon of the brown sugar into the lukewarm milk and allow to sit until foamy, 10 to 15 minutes.
• Whisk the flour, remaining brown sugar, and salt in a large bowl. Add the 2 tablespoons softened butter, use your fingertips to rub the butter into the flour mixture, breaking it up into tiny flour-coated pieces the size of breadcrumbs. Stir in the yeast mixture and the beer using a wooden spoon or rubber spatula to form a shaggy mass.
• Turn the dough out onto an unfloured (or very lightly floured) work surface and knead eight to ten times, until all of the flour is just incorporated. You don't want to over work it or the butter may melt too much. The dough will not be a smooth mass; you will see some flecks of butter. It should be soft and tacky, but not sticky. Adjust as needed with flour or water. 
• Lightly oil a large bowl and set the dough into it. Cover the bowl with plastic wrap. Place in refrigerator for 8 to 24 hours (24 will give you the best flavor).

Make the butter block (when you put the dough in the fridge to rest)

• Fold and blend (light kneading) the slightly softened butter and flour together until well blended, using a bit of elbow grease. Or beat the two together in the bowl of a stand mixer, using the paddle attachment until it forms a smooth mass – this should take about a minute. You want the butter to be pliable without beating air into it or melting it.
• Spread the butter between 2 large sheets of plastic wrap or parchment or wax paper, and use a rolling pin to shape into an evenly-flat rectangle that is 8 x 9 inches (20 x 23 cm). Use a straight edge to form corners, but work quickly as you want the butter to stay cool. Wrap the block in plastic and refrigerate until you're ready to roll out the dough (preferably overnight with the dough).

Prepare the baked baking soda (once the dough and the butter blocks are in the fridge)

• Preheat the oven to 250°F (120°C ). Spread ¼ cup (about 60 grams) of baking soda out on a baking tray lined with parchment paper or foil (or in a foil-lined pie pan). It will decrease in weight, but shouldn't decrease in volume. Slide it into the preheated oven and bake for 1 hour. Cool completely, then store in an airtight container at room temperature.

Day 2: Prepare the puff pastry

• 1st turn:

  Turn the dough out onto a lightly floured work surface. Roll it out into a 10 x 15 inch (25 x 38 cm) rectangle about ¼-inch (1/2-cm) thick. Using your hands, press the dough flat then gently pull and stretch the dough to form straight edges and sharp corners. Brush excess flour off of the dough. Set the dough with a long edge facing you.
• Mentally divide the dough into 3 equal portions (make slight marks using a tape measure, if needed). Place the butter block over the right 2/3 of the dough, leaving a 1-inch border on the outer edges.
• Fold the empty (bare) left portion of the dough over the middle third (brush off excess flour from the dough). Now, lift and fold the right section of dough over that (the right 1/3 of dough with 1/2 the butter on top). You should have 3 layers of dough that encase 2 layers of butter (dough-butter-dough-butter-dough).
• Pinch the outsides and the seams together and lightly press the layers together using a rolling pin. This completes the first turn. Wrap well in plastic wrap and refrigerate for 1 hour.
• 2nd turn:

  Remove the dough from the fridge and set it on your lightly floured work surface. Roll dough out into a 10 x 20-inch rectangle, pulling, blocking, and stretching to form straight edges and sharp corners. Brush off any excess flour. Set the dough with a long edge facing you (now measure and lightly mark the dough in 4 equal lengths). 
• Fold both of the short ends in to the center, leaving a 1/4 -inch gap where they meet (think of a book jacket – so the two edges are brought towards the center). Brush off excess flour. Fold one side of the dough over the other. You should have 4 layers of dough.
• Lightly press the layers together using a rolling pin, and square and sharpen the edges and corners. This completes the second turn. Wrap in plastic and refrigerate for 1 hour.
• 3rd (and final) turn:

  Lightly dust your work surface and the top of the dough with flour. Roll dough out into a 10 x 15-inch rectangle. Do another trifold, as done in the first turn (with the longer edge of the rectangle in front of you left to right, lightly mark the dough in 3 equal lengths, fold the left 1/3 in on top of the centre 1/3, then bring the right 1/3 over the top for 3 layers of dough; press the packet together). 
• Square the edges and sharpen the sides; wipe off excess flour. Wrap in plastic and refrigerate for at least 2 hours, but up to another 24 hours (I leave mine in the fridge for 24 hours; the dough will rise more than if left to rest for only 2 hours or so).
• * At this point, you can wrap the dough tightly in plastic wrap, slide it into a freezer bag, and freeze for up to 1 week. Defrost overnight in the refrigerator before proceeding to final shaping.

Day 3: Final shaping, dipping, and baking

• Line two baking sheets with parchment paper and set aside.
• Lightly dust your work surface and the top of your dough with flour. Roll out into a 15 x18-inch (38 x 45 cm) rectangle that is about ¼ inch (1/2 cm) thick. Pull and stretch to form straight edges and sharp corners. Patch any holes where butter may have popped through by dusting them with flour. Brush any excess flour off the dough.
• Cut the rectangle in half, creating two 15 x 9-inch (38 x 23 cm) sheets of dough. Using a pizza cutter or bench scraper, cut each piece of dough into three equal strips, the short way (you should now have small 9 x 5-inch/23 x 13 cm rectangles). Then cut each strip in half diagonally, so that you left with 6 long triangles. Repeat with other half of dough.
• (At this point, before rolling each long triangle, I gently lift each triangle one by one and flip it over, brushing off all excess flour then move the brushed triangles to the parchment paper-lined baking sheets to roll up)
• Beginning at the wide base, roll the triangles up, tugging on the tip to elongate it slightly (dip a finger in water and dampened the tip – about 1 inch), then gently pressing it into the dough.
• Place on the prepared baking sheets with the tips tucked under, and curve the ends to form crescent shapes. (Leave space between the croissants to rise and the puff up during baking)
• Cover the croissants with damp, clean kitchen towels (I loosely cover each croissant-filled baking sheet with plastic wrap then loosely lay a clean kitchen towel on top of that) and allow to rise at cool room temperature until they have almost doubled in size and feel spongy, about 2 hours.
• After the 2 hours, slide the croissants into the refrigerator for 20 minutes while you prepare the dipping solution (I do not do this; my fridge is not big enough and it works perfectly).
• Preheat oven to 425°F (220°C), positioning one rack in the upper third of the oven, and one in the lower third (in a small French oven, I bake one baking sheet of croissants at a time).

Prepare the dipping solution

• Add the baked baking soda to 8 cups of cold water in a pan or bowl (make sure the recipient is not too large, the croissants must be immersed totally in the water) and stir until completely dissolved. 
• One by one, place a croissant on a slotted spoon and dip into the dipping solution (baking powder water bath), lift out and allow the excess to drip off, then set back on the lined trays. Repeat with the other croissants.

Finish them off (finally) and bake

• Brush the tops of the dipped croissants with the egg wash, then, if you like, but it isn’t necessary, sprinkle with coarse salt, sesame seeds or poppy seeds, if using, or even pearl sugar.
• Slide into the 425°F (220°C) preheated oven immediately and bake for 15 – 20 minutes (rotating pans from front to back and top to bottom halfway through), until they are deeply browned, crispy, and flaky. They should feel light and airy if you pick them up (during baking, the croissants may release buttery liquid; don't worry about this, just carefully lift the croissants off of the buttery parchment with a spatula onto cooling racks as soon as they are baked).
• Transfer to a wire rack to cool for 10 minutes before serving. They are best enjoyed the day they are made, ideally warm from the oven. Store any extras in a paper bag for a day. You can reheat them by placing them in a 350° F (180°C) oven for about 5 minutes.