Musar על שבת 274:11

The reason that the wine saved from גן עדן is called משומר, is that its dregs, its yeast has been removed. When Eve squeezed the grapes and gave her husband to drink she had not removed those dregs first. The Torah (Numbers 18,8) writes of Aaron, who was the rehabilitation of Adam, that he was to be the recipient of what G–d calls משמרת תרומתי, "The residue of My gifts." It is also said of Abraham (Genesis 26,5) וישמר משמרתי. Some of our sages interpret the repetition of the expression שמר in this verse as meaning that Abraham introduced "fences," preventive measures around G–d's laws so as to ensure that the laws themselves could not easily be violated. This would be similar to the Mishnah in Shabbat 20,1 permitting the suspension of a sieve i.e. meshameret on the holiday in order to catch the shemarim, sediments, yeast, of the wine.