I need to learn how to make Arepa flour from scratch for the same reason. Making them from fresh corn, while tasty, is time consuming and having it ready for mix and cook makes up for any loss of taste.
I figure in case of emergency one of the major things I will be lacking is enough hours in the day to do things. Having short cuts available will be just as handy then as now.
It is good to have shortcuts. But you just can't beat some stuff that takes a long time. That's why I only make tamales about 4 times a year. ;)
I am still working on building my mud brick horno, because I used one in NM, and I've never baked better bread. And I've baked bread all over the world. Forget the fancy french ovens with the injected steam... a good horno beats it hands down in my opinion. That also takes time to build, but I've got more time than money right now, so it's ok.
/johnny