I'd guess so. I've been living in Spain for the last 9 months and I've never heard it called "jugo" and I've never heard anyone using that word when referring to juice. All the lessons and translations here are Latin American Spanish - the pronunciation is too. This is just another difference between the variations of Spanish, and Duolingo follows the Latin American version
yeah, but it's the concept they are teaching you, not the words/sentences/sentence structures themselves. It's taking baby steps...As a baby you don't start speaking and then like magic can belt out a structured piece of literature like the Emancipation Proclamation! I mean, C'mon...
Do you really use an indefinite article with jugo? I'm a native English speaker, and I can't imagine ever saying "an orange juice."
Maybe if it was in a little can on a shelf, and someone was passing it to me, but certainly not the more typical scenario of having a jug and pouring a glass. I'd just say "I want some orange juice."
It's not a countable noun.
This sentence does sound strange out of context. At the very least, writing "I want good orange juice" should not be marked wrong, as was the case for my answer.
You are right that juice is not a countable noun by itself. However, we can use it with a countable noun to make the entire phrase countable. For example, "I want a good glass of orange juice" or "I want a good brand of orange juice". Sometimes this countable noun is omitted, which results in "I want a good orange juice". A strict grammarian may regard this as incorrect, but it is used in conversational English.
The accepted English translation for this, "I want a good orange juice," is awkward. You can invent scenarios in which someone might say that, but you have to because it's weird. Is the Spanish also awkward, or is it just a straightforward way of saying "I want good orange juice"?