Yes and no... technically, it should be „Saftes“, but nobody says that without sounding very weird. I'm not sure why the genitive declination isn't used as such.
A (roughly) analagous case in English is the use of the objective pronoun for the predicate of "to be". For example, if you wanted to identify yourself in a picture of yourself, the proper construction is "That is I.", but absolutely nobody fluent in English would say that. Instead, we use the grammatically incorrect "That is me."
The 'quantity_ingredient' format (with no "of") is technically not correct in English (at least not American English) and only used in abbreviated recipes or product labels. Since this sentence uses "please!" the speaker is clearly requesting/ordering 10 liters of juice, not writing a recipe or reading the label of an (improbable) 10-liter bottle of juice.
You misspelled zehn.
You used a lowercase first letter for the nouns Liter and Saft.
You used the preposition aus (roughly, "out of" or "made from") which makes little sense here -- the litres are not made of juice; they just measure how much juice you have.
German doesn't use a preposition there at all; it's simply zehn Liter Saft, drei Meter Stoff, fünf Kilo Reis etc. For ten litres of juice, three metres of fabric, five kilograms of rice.