2,415. Preventive Measures

Maachalos Assuros 13:13

Sometimes the prohibition against libation wine doesn’t apply but the Sages prohibited things as a preventive measure. These include: a non-Jew may not mix water into wine in a Jew’s possession so that he doesn’t come to pour wine into water; a non-Jew may not bring grapes to the winepress so that he doesn’t press them or touch the wine; a non-Jew may not assist a Jew in pouring wine from one vessel to another so that the Jew not leave the wine in the non-Jew’s possession where it will flow from the non-Jew’s power. While these things shouldn’t be done, if the non-Jew assists, mixes the water or brings the grapes, the wine remains permitted.

Maachalos Assuros 13:14

It’s permitted for a non-Jew to smell Jewish wine and it’s permitted for a Jew to smell libation wine. This is permitted because aroma is literally insubstantial and therefore of no consequence.