Only eight months late, but I have now made the first attempt at black pudding. My cooking partner and I followed the (apple/chestnut) boudin noir recipe from Modernist Cuisine, pretty closely, I think the only substitute was butter for foie gras fat. We used reconstituted dried pig's blood as we couldn't get fresh stuff. Packed in cow casings (~4cm diameter), which was pretty easy, the mix is really liquidy so we only needed a funnel to fill the casing. Made 8 very hefty ~450g sausages. They are now in the fridge to finish setting (they were very soft before cooking, and a bit firmer after), and I'll try them tomorrow for the first time, better be damn good or I'm not gonna even post the pictures!
Blood Sausage Parametric (%) Grams
Pork fatback 42 420
Butter 16 160
Pork blood 100 1000
Whole milk 20 200
Calvados 8 80
Ground bay leaf 0.3 3
Onions 100 1000
Chestnut puree 20 200
Fine breadcrumbs 13 130
Apple 10 100
Chestnut flour 5 50
Salt 5.4 54
Activa RM 0.6 6
total: 3403
blood is reconstituted per instructions. onions (diced finely) are softened in some butter over low heat. in a small pot chestnut powder and puree, rest of butter, milk, salt, apple, bay leaf are whisked and heated to a simmer, and left to cool. fat is diced, blanched quickly, drained. onion, fat, breadcrumbs, calvados, activa, chestnut mix and blood (ie everything) are mixed well in a large bowl. casing is prepared normally, and the mix is funneled into the casing, which is tied off with butcher's string as desired, leaving a short linker segment between two sausages. sausages are blanched in boiling water 1 minute, and cooked in a waterbath at 82 degrees for 1 hour.