Tortillas made with the blue massa harina certainly are pretty, they are a slatey grey colour rather than blue and they have a coarser texture than tortillas made with white massa. I can notice no difference in that taste. Diana Kennedy is very sniffy about tortillas made with either blue or in particular yellow corn. She is probably being somewhat absolutist about blue tortillas as they are unusual and pretty however when it comes to the yellow corn I have to agree with her. There is something off about the smell of yellow tortillas, they have a musty unpleasant smell, there is no difference much in the taste or texture, but I would see no reason to to ever select yellow tortillas instead of white.
Based on subsequent experiences with white massa de harina I think some of my earlier comments require slight modification, specifically on the use of warm water and resting the masa dough before pressing and cooking.
- Using warm water does seem to make a difference, it seems to take less warm water than cold to produce a dough, it also seems to produce a smoother dough.
- Also dough that is rested the dough for 20 minutes or so before pressing does seem to have hydrated and relaxed more than when used immediately.