There is something self-contradicting about the allegory of this verse. The γν ("blood") of the grapes that flows from a winepress is the precious product, treasured for its qualities. To switch to actual γν of enemy soldiers disrupts any consistency to the allegory and has no precedent in the Bible. The γν of the grapes is never permitted to simply run off into the fields as waste. A fortiori, drinking γν is prohibited by Torâh. It is the pulp that is disposed of, not the γν of grapes. Yet, this verse makes no mention of disposing of the pulp.
Interestingly, this could have been a redaction by copyists who assumed that the phrase, found several times previously, was "originally intended." Such redactions have been documented even by the most eminent Christian scholars (cf. note "Redactions" in "Discontinuity" section of Who Are the Nәtzârim? Live-Link). This seems an unavoidable conclusion as the same passage is found in the next chapter (15.1) describing the ultimate rewards being doled out as "the outrage of Ëlohim."
Moreover, though there is no documented redaction in the extant mss., there is a duplication of near identical phrases, used often elsewhere, that could explain the enigma. The phrase "of the anger of Ëlohim" is του θυμου του θεου (tou thumou tou theou). There are many ways in which this phrase could have become duplicated, by error or deliberately. If the phrase του θυμου (tou thumou; of the anger) wasn't originally included, then the entire passage reads dramatically differently, describing the process of separating the desirable γν ("blood") of the recently reaped grapes (Torâh-observant Jews and geirim) from the undesirable pulp.
The questionable phrase is also suspect because of the misojudaic inflection the redaction would have introduced.
A candidate similar Greek term, θελημα (thelæma; will, desire, pleasure), offers a likely alternative "original intent" if a misojudaic redaction did, in fact, occur in these passages.