What is the correct spelling of the cooking term 'shitrein'? Does it even exist?

Can't find it in my 1940 edition of Encyclopedia of Cooking or my Food Lover's Companion (2009)

From where is the origin of the term?

'Schitt' is in German the colloquial form of the vulgar "Scheiße"; 'rein' means "clean".

I could imagine that this term was used with e.g. some poultry recipes or similar, centuries ago.

I was thinking it was a German or Yiddish idiom.

This is very interesting to me and I would really like to find this term myself.

It might be the Yiddish "**** a rein" (in German: 'schütt' es rein'), which just means that you can take a [little] bit more, (translation: pour it in), don't look at the quantity ...

The root of shitrein, ****, is a perjorative for feces. It is commonly used as a curse word and is considered vulgar.

It would therefore not be appropriate to use this word when referring to food in polite company.