would get the hummus really smooth and creamy without skinning them.
I've read that adding baking soda to the cooking water helps with this, and I did do that to the last batch since the beans were so old. And the beans, as well as the skins, did get really soft (I removed the skins anyway). But I've also read that adding baking soda depletes thiamine (vitamin B1), so I guess each person has to decide for themselves what to do.
When I get a fresher bag of beans, I'll keep experimenting with the skin issue, whether to leave it or remove it. But I doubt I'll use the baking soda.