Q. The minhag to eat macholei cholov in Shavuos is very important in my family and I have always kept it. But now I’m in a very strict diet. Can I keep it by just drinking skimmed milk? If not do I have to be matir neider?
A. Horav Shlomo Miller Shlit’a pointed out that here are numerous different reasons for eating milk food on Shavuos, most of them would apply equally to consuming solid food, drinking milk or ingesting solid edibles that were mixed or soaked in milk. To quote two cited in Shulchan Aruch, the Remoh (O.H. 494: 3) mentions, that it commemorates the shtei halechem korban offered on Shavuos. This would apply also to bread soaked or baked with milk. So too would the B’air Haitev reason (ibid: 8) quoting the Zohar that “the blood turns into milk” (Bechoros 6b) and middas haddin or the quality of severe judgment turns into rachamim or compassion and kindness by learning of Torah. The same would apply to most other rationales that explain this minhag.
Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit’a