Kindly I had tried this delicious recipe and have a query; the custard looks like cooked white egg while it «s taste is sweet and I had followed or your steps only one change I didn't use whipped cream I used fresh cream with same amount of milk as yours and honestly I beated the egg by my hand as much as I can and it didn't change to white color. (eugeniekitchen.com)
As a guide, the FDA states there's 43 mg of caffeine in 100g of dark chocolate and 20 mg in the same amount of milk chocolate. (dailycupo.com)
So in this case you'd use milk because it's the liquid the recipe calls for - you use the same amount of milk, sugar, and yeast that the recipe calls for and let the active yeast proof in the warmed milk (dissolve the sugar in it) for about 5 - 10 minutes until frothy. (ahintofhoney.com)