I'm trying to make a recipe from Cooks Illustrated that calls for 0.5 cups of dried buttermilk powder. CI indicates that this is found in most supermarkets near the dried-milk products or in the baking aisle. So far I've tried several of the big supermarkets in Montreal (Loblaws, Maxi, Provigo, Adonis, Fruiterie 440) and tried all the weirdo shops at Jean-Talon Market but they all don't carry it.
Does anybody know where buttermilk powder is found? I don't wish to substitute the ingredient so I'm really interested to hear if somebody has ever seen this product anywhere?
7075 Avenue Casgrain, Montreal, QC H2S, CA