“Why don’t Mexicans have barbecues?”/“Because the beans fall through the grill.”

A barbecue joke is:
 
Q: Why don’t Mexicans have barbecues?
A: Because the beans fall through the grill.
 
The joke—sometimes regarded as offensive—has been cited in print since at least 1983. “Why can’t Chinese barbecue?”/“Because the rice falls through the grill” is a similar joke.
   
     
Google Books
Totally Tasteless
By Blanche Knott
New York, NY: Ballantine Books
1983
Pg. 9:
Why don’t Mexicans have barbecues?
The beans fall through the grill.
 
Google Groups: rec.humor
non-coded joke! - offensive to Americans (rot 13)
Rodney Shojinaga
8/11/90
(...)
Why don’t Mexicans barbeque?
The beans fall thru the grill.
     
Google Groups: rec.humor
ethnic jokes
Dan Hay
12/10/92
(...)
Why don’t they barbecue in Mexico?
The beans fall through the grill.
 
Google Books
Little Buddy Goes to Scout Camp
By Don Wible
Xlibris Corporation (Xlibris.com)
2013
Pg. 32:
“Why can’t Mexicans barbeque . . . because the beans fall through the grill.”
 
YouTube
Jokes - Why don’t Mexicans like to barbecue? Because the beans fall through the grill.
jokesus
Published on Oct 2, 2015
Joke :
Why don’t Mexicans like to barbecue?
Because the beans fall through the grill.
 
Google Books
Food Jokes
By Jeo King
Marine Publishing
2016
Pg. ?:
Q: Why don’t Mexicans like to barbecue?
A: Because the beans fall through the grill.