“Tastes like cardboard” is a popular saying, even though most people have never eaten cardboard. The saying has applied to foods such as bad bread and bad pizza. “The cake tastes like foam and cardboard” was said by a soldier in Germany in 1918. “It tastes like slightly sweetened cardboard” was cited in 1938. “Bread is made with so many ingredients that it tastes like cardboard” was cited in 1941.
 
“Tastes like chicken” is another popular phrase about taste.
   
 
5 April 1918, Fairfield (IA) Tribune, “Kaiser Hated Says Returning Soldier,” pg. 3, col. 1:
“Germany has little natural food. Everything is substitutes. Milk, coffee, sugar, cake, all substitutes. The cake tastes like foam and cardboard.”
 
13 December 1938, Corpus Christi (TX) <>Times, “Christmas Approaches in Hollywood” by Frederick C. Othman (UP), pg. 5, col. 2:
We hope you receive none of this; it tastes like slightly sweetened cardboard.
(Glazed fruit.—ed.)
   
15 March 1941, Winnipeg (Manitoba), Free Press, “Norway Being Starved,” Magazine Sec., pg. 7, col. 6:
Bread is made with so many ingredients that it tastes like cardboard.
 
28 May 1945, Southern France Stars and Stripes(Nice, Provence. Alpes. Cotes d’Azur) and Paris Stars and Stripes:
The pastry still tastes like cardboard, but the confectionery shops are always filled with soldiers.
 
16 April 1954, Oakland (CA) Tribune, “Atomic Search Turns Up Key to Dental Problem” by Frederick C. Othman, pg. 12, col. 3:
It taste like damp cardboard, sprinkled lightly with engine oil.
(A hamburger in a cellophane bag for six months.—ed.)
 
28 July 1956, Boston (MA) Traveler, “Rigney Baffled Over Plight Of His Giants Team” (UP), pg. 7, col. 1:
His appetite is poor, what food he does eat tastes like cardboard.
     
Google Books
The 87th Precinct
By Ed McBain
New York, NY: Simon and Schuster
1959
Pg. 396:
“It tastes like cardboard, if you want to know. Now, don’t misunderstand me. I like cardboard. My wife often serves cardboard for dinner. She has some wonderful recipes for cardboard.”
 
6 December 1961, Evansville (IN) Courier, “Stan’s Postcard: Tortillas Fight Fallout” by Stan Delaplane, pg. 10, col. 3:
To me it tastes like cardboard.
(A tortilla.—ed.)
   
Google Books
The One and Only You
By Bruce Larson
Waco, TX: Word Books
1976, ©1974
Pg. 18:
However, there is one major drawback. The milk “tastes like cardboard.” The researchers assume that beef produced in the same way will also taste like cardboard.
   
Google Books
Journalese:
A Dictionary for Deciphering the News
By Paul Dickson and Robert Skole
Portland, OR: Marion Street Press
2012
Pg. ?:
TASTES LIKE CARDBOARD. Restaurant reviewers and food writers are among the very few people on earth, except teething babies, who know What cardboard tastes like.
 
Twitter
Cecilia
‏@Ceciliaax
Whole grain pasta tastes like cardboard but who am I to deny my body it’s recommended daily fiber intake
3:47 PM - 21 Apr 2015