[Sca-cooks] Buttermilk?

[lilinah at earthlink.net]

With all this discussion of sourdough and lactic acid fermentation, i 
have a question entirely unrelated to bread...

In the US the only buttermilk i think i have ever drunk is commercial 
cultured dairy buttermilk. I am quite fond of the stuff, especially 
in the summer, and can easily go through a quart in a day or a tad 
more.

Question One

To the best of my knowledge, buttermilk was originally the whey (if 
that is the appropriate word) left after churning cream into butter. 
I believe i have never had this. I would assume it would not be as 
thick as the cultured buttermilk, but that's just a guess. So, what 
would its texture be and why would it be sour?

(side bar: i seem to recall a commercial brand that claims to be the 
result of the process of churning butter, but as best i recall, it 
didn't seem vastly different from my preferred cultured brand. 
Perhaps real churned buttermilk actually isn't?)

Question Two

When i was in Morocco, i had a dairy beverage which name has been 
translated into English as buttermilk, but i know nothing of its 
production method. It was indeed thinner than the usual USAmerican 
cultured buttermilk. But what i found most interested was the mouth 
sensation it induced. While not in the slightest carbonated, there 
was a "fizzy" or "tingly" mouth feel. Was this due to lactic acid 
fermentation? I've had plenty of dairy products produced by 
lactobacilli and never noticed this sensation. What is this? I'd love 
to reproduce it or find a source to purchase it.

Thanks for any clues,

Anahita