I always knew crystal and roasted malts were less fermentable than base malts but I never really knew how much. I was surprised at how not fermentable roasted malts are. I guess it also follows that lighter crystals are likely more fermentable than darker crystals. Something to keep in mind when making recipes:
httpss://byo.com/hops/item/629-fermentability-advanced-brewing
Pale base malts and adjunct grains produce the most fermentable wort (wort that may ferment to an apparent attenuation of 70–80%), while darker specialty malts contribute to less fermentable worts. Caramel and crystal malts will yield wort that only ferments to 40–60% apparent attenuation. With dark roasted malts, this may be as low as 25%. On the other hand, simple brewing sugars have very high attenuation. In the case of table sugar (sucrose), the apparent attenuation can be more than 95%.
Edited by Evil_Morty, 27 June 2017 - 07:23 AM.