U̶n̶l̶e̶s̶s̶ ̶b̶o̶i̶l̶i̶n̶g̶ ̶t̶h̶e̶ ̶w̶a̶t̶e̶r̶ ̶r̶e̶s̶u̶l̶t̶s̶ ̶i̶n̶ ̶p̶u̶r̶i̶f̶y̶i̶n̶g̶ ̶i̶t̶,̶ ̶b̶o̶i̶l̶i̶n̶g̶ ̶p̶r̶o̶b̶a̶b̶l̶y̶ ̶d̶o̶e̶s̶n̶'̶t̶ ̶d̶o̶ ̶a̶n̶y̶t̶h̶i̶n̶g̶ ̶b̶e̶s̶i̶d̶e̶s̶ ̶s̶l̶i̶g̶h̶t̶l̶y̶ ̶s̶p̶e̶e̶d̶ ̶u̶p̶ ̶a̶u̶t̶o̶l̶y̶z̶i̶n̶g̶ ̶t̶h̶e̶ ̶f̶l̶o̶u̶r̶ ̶a̶n̶d̶ ̶w̶a̶t̶e̶r̶.̶ *This is probably wrong--see edit. Didn't know about this process because you'd never want to do it with anything you're going to add yeast to.

I've done a fair amount of experimentation on on bread making, and a very important step in bread making is autolyzing[0] the flour and water (letting the flour and water rest for a period after combining them).

However, the only reason water temperature matters in autolyzing is because you want an optimal temperature for yeast at the end of the autolyzation process[1].

More likely, what matters more is not the temperature of the water (assuming distilled, pure water, not subject to local tap water differences), but the time you let it the flour and water autolyze. My suspicion is that even though tortillas don't involve yeast, autolyzation is still important for optimal results.

NINJA EDIT:

Interesting, after doing some more research, I discovered boiling water is actually used to gelatinize flour--resulting in much more elastic dough, as you specify[2].

[0] https://www.kingarthurflour.com/blog/2017/09/29/using-the-au...

[1] https://www.weekendbakery.com/posts/a-few-tips-on-dough-temp...

[2] http://thebreadmaiden.blogspot.com/2016/02/the-science-behin...

Hot water encourages hydration of the flour and gluten development, resulting in a more elastic/homogeneous dough. IMHO, the hottest water from the tap should be good enough for that purpose.

True, but hot tap water doesn't always taste very good. If you've ever had seen the inside of a water heater, you will never want to consume hot water again. It's often full of rust and scale.

You and the other commenter are correct. Just meant that temp ~120F as a reference. Have lived in a calcite water area, no fun.

Water from the standing hot water heater typically doesn't taste as good.

agreed with this, hot liquids def made things much easier