Please excuse this naive question from someone almost totally ignorant of the language.
In an exchange having a German context, I wanted to ask the well-known (in the US) and snarky question "Where's the beef?". What came out of the Universal Translator (-cough-) was "Wo ist das Rind?"
Correct, I'm sure, but it misses the flavor of "Where's" as opposed to "Where is". So I wrote it as "Wo'st das Rind?", and the point was made.
Is this remotely acceptable in colloquial German?
“Wo’st” isn’t a typical German contraction.
You could perhaps get away with something like
That said, contractions are less standard in German than in English, where a whole range of auxiliary verbs shrivels down to “‘s” and “‘d” both in written and spoken language. In German, you are (as a rule of thumb) better off with the full version in written language, apart from e.g. a theater script trying to mimic spoken colloquialism.
And finally, while Americans are familiar with the phrase “where’s the beef”, there’s no direct translation that also captures the meaning. For that, you’d have to find an alternative - but that’s probably best asked in another question.
Such contractions are not usual in this form, and they certainly are not something one ever writes - unless one wants to mimic a certain dialect or slur.
But then such sentence would probably read more like (in my regional flavour), shortening "wo ist denn" to "wo is'n":
Wo is'n das Fleisch?
Wo is'n das Rindfleisch?
Wo is'n die Kuh?
However as suggested in the comments, if you mean the idiom "Where's the beef?" which is somewhat synonymous to "What's the point?" / "Is that really worthwhile?", then I'd probably go for something like
Was soll'n das?
Wat soll dat denn? (with more slang pronounciation)
If the intend is more like "what's in for us?": Was haben wir davon?
Und was ha'm wir davon?
No, "Wo'st" is not a contraction that would be used in German.
In general, contractions are not commonly used in written text, formal or informal.
That said, in written text that imitates a spoken conversation like chat or instant messaging contractions like "Wo issn das?" or "Biste fertig?" are sometimes used. "Gibt es ...?" is almost universally written as "Gibts ...?".
Please note that you need to write the apostrophe only if it would otherwise be ambiguous.
"Proper" written contractions cannot elide much more than "e" with an "'". Spoken language has a number of comparatively informal contractions that don't quite reach the level of French (which writes more syllables than spoken in even the most formal language use).
At any rate "Wo's das Rind" (slightly more acceptable than "Wo'st" but still wrong) would be "Where's the cow?". Which is cute but probably not what you meant.
If the meaning was supposed to be "I want to see something more substantial" (typically concrete commitment), the German idiom would be "Jetzt mal Butter bei die Fische!". Note that this is decidedly not correct German but a phrase borrowed from Plattdeutsch (where pronunciation and typical phonetic spelling would be quite different but did not venture into mainstream German along with the phrase).
In German, there are contractions, but they follow different rules.
In your example, you would not drop one of the consecutive vowels, but rather one of the consecutive consonants. So "Wo ist das Rind(fleisch)?" would become "Wo is' das Rind(fleisch)?".
It would be acceptable in speaking, though quite uncommon in writing, to contract even more to "Wo's' das Rind?".
I'd like to note that "Wo is'n das Rind?", as proposed in the other answers, is not actually wrong, but it's a contraction of "Wo ist denn das Rind?" which was not used in the question like this and isn't an exact translation of "Where's the beef?" either.
"Wie geht's" is a very common example of the very few traditional High German contractions. You will find more contractions in the regional dialects, but they are specific and rarely written out, unless the dialect itself is being emphasized. The Hessian "Ei-guda-wie" is one such example, if it can be considered a proper contraction.
Writing out a contraction (that's not "wie geht's") would almost come across as crude (depending on the region/person) -- unless, again, you're emphasizing the crudeness/slang itself, such as quoting a drunk from the subway or obnoxious teens.
