Spelling of "juice"?

[Daniel]

We know there are many oddities of English spelling, but I just noticed one I had never questioned before, and I can't see a pattern.

juice... what's the <i> doing there?

The history of the word and spelling in other languages doesn't explain anything:
http://etymonline.com/index.php?search=juice

juice (n.)
c.1300, "liquid extract obtained by boiling herbs," from Old French jus "juice, sap, liquid" (13c.), from Latin ius "broth, sauce, juice," from PIE root *yeue- "to blend, mix food" (cf. Sanskrit yus- "broth," Greek zyme "a leaven," Old Church Slavonic jucha "broth, soup," Lithuanian juse "fish soup"). Meaning "liquor" is from 1828; that of "electricity" is first recorded 1896.

So is this just a random spelling variant that caught on? Or is there a phonological reason?

[freknu]

It does seem wierd compared to words like "puce", "truce", "spruce", and so on, but perhaps the spelling follows words like "bruise"?

[Daniel]

Ah. Bruise, cruise. Any idea there?

[freknu]

Not really. At least "bruise" and "cruise" show the /i/ in the source:

bruise < Norm. bruiser < Gaul. *brus-
cruise < Dut. kruisen, kruis < Lat. crux

I don't know about OEn/MEn, but would it have been orthographical even back then, or would the /i/ have been pronounced?

(EDIT)

I would guess that it's purely orthographical, for some reason it just ended being spelled like that, perhaps drawing from similarly spelled words. The pronunciation actually follows the rest of the Germanic languages and shows no evidence for why it would need an /i/.

[Daniel]

I agree. French "jus" suggests there was no /i/.

It's possible this was due to the great vowel shift: it was a front rounded vowel spelled ui as a hybrid of the two. Maybe?

[freknu]

So there were two variants: jūs /juːs/ and jūis /jyːs/, and after /yː/ became /iː/ the /juːs/ variant survived but adopted the latter spelling?

[Daniel]

Weird! Good point. It was an incomplete thought before. I'm not sure. I have no evidence except speculation.
Spelling is much more affected by analogy than other parts of the linguistic system so it's likely that it could be just based on other words that way. Still there should be something to compare it to for that analogy....