"Make(s) your tongue slap your brain(s) out” means that something is mighty fine cooking. The jocular food expression is used in the South and has been cited in print since at least 1959.
29 September 1959, Baltimore (MD) Afro-American, “Meet Dr. Williams, Cook: He’s a college president who makes tasty barbecue” by Elizabeth M. Oliver, pg. 30, col. 6
AS THE FOLKS sitting around his table say: “The president’s hot barbecue’ll make your tongue slap your brains out, it’s that good.”
Dr. Williams himself is quite proud of his open pit cooking.
(Dr. John T. Williams of Maryland State College—ed.)
Google News Archive
8 March 1977, St. Petersburg (FL) Evening Independent, “Happiness Comes As Surprise” by Hazel Geissler, pg. 11B, col. 1:
Dinner. Orfie said was so good “it was enough to make your tongue slap your brains out.”
Google News Archive
19 March 1978, Tuscaloosa (AL) News, “Twitching noses his specialty” by Mary Jacq Rainey, pg. 1C, col. 6:
“I’ve got some sausage made out of those rabbits that would make your tongue slap your brains out,” he said, hee-hawing at his joke.
Stories about the old days
By Bill Harris
Used to be five bars in these two blocks here alone. Along here had restaurants, served down-home cooking so good make your tongue slap your brains out;...
United States. Dept. of Defense. High School News Service
Volume 37, Issues 2-6
“(My cooking) will make your tongue slap your brain!”
Google Groups: alt.appalachian
Date: 24 Feb 1995 00:04:23 GMT
Local: Thurs, Feb 23 1995 6:04 pm
Subject: Re: Slaw Dogs
Boys, if you want to taste the best slaw dogs this side of the Mason-Dixie, try Stewart’s Drive-In, at 24th St. and 5th Ave. in Huntington, WV. So good, they’ll make your tongue slap your brains out!
Google Groups: rec.food.cookinjg
From: Jan Blair
Subject: Re: Yankees and grits
It’ll make your tongue slap your brains out.
Google Groups: atl.general
From: (John Miller)
Subject: Re: Best Que in Atlanta?...Yankees need not reply
Harold’s food will make your tongue slap your brains out.
Google Groups: bit.listserv.dorothyl
From: “Jeanne McWhorter, MSW”
Subject: Re: regionalisms
This food is so good it’ll make your tongue slap your brains out
Google Groups: rec.food.cooking
From: Mike Perry
Subject: Re: Favorite Meal
‘make ya tongue slap ya brain’
Google Groups: alt.support.depression.flame
Subject: Re: HELLO ALL MY LOVING FANS
>Somewhere I have a recipe for a grits casserole made with cheese and
>jalepeno peppers that would make your tongue slap your brain silly.
jeez, i would think it’d be the other way around. the brain slapping the tongue silly. as in “hey! don’t eat that, are you nuts?? knock it off! go get a nice piece of pie, or something!!”
22 August 2003, India in New York, food section, pg. 30, col. 4:
But there isn’t a dish that would, as they say in Alabama, make my tongue slap my brain.
The Cracker Kitchen:
A Cookbook in Celebration of Cornbread-Fed, Down Home Family Stories and Cuisine
By Janis Owens
New York, NY: Scribner
They’re masterpieces in their own way, and in Cracker idiom, will “make your tongue slap your brain.”
Paula Deen’s the Deen Family Cookbook
By Paula Deen with Melissa Clark
New York, NY: Simon & Schuster
This casserole is so full of flavor it’ll make your tongue slap your brains out!
Thoughts. Hopes, and Retrospective
Sunday, July 18, 2010
“Make Your Tongue Slap Your Brain Out” Rib Recipe