Daf Yomi - Beitza 23 - Fragrance on the Hands of the Kohanim

Rabbah and Rav Yosef both state that it is prohibited to turn over a cup with fragrance on top of silk garments since it will produce a new fragrance in the clothing and this forbidden because it's creating something new. Rashi explains that this is Rabinically forbidden since it is regarded as if he is doing a new melocha. Rashi in Shabbos (51b) states the same thing regarding transforming snow into water. It is noteworthy that creating something new which is molid and when something achieves its present useful state on Yom Tov which is nolad are two separate things and have two different sets of halachos. something that is nolad is considered muktza and one is prohibited from handling on Yom Tov; however molid which resembles a melocha is permitted on yom Tov if it will involve a preparation for food.

The Taz (O"C 511) writes that there are those that place a smelling fragrance of oil into the water that the kohanim wash their hands with on Yom Tov. This, he rules, is forbidden because it creates a smell in the water on Yom Tov and it is even forbidden to place the oil into the water prior to Yom Tov for it will be producing a smell on their hands on Yom Tov.

Chacham Tzvi (92) disagrees and maintains that there is never an issur of molid in foods or drinks in the same manner as there is no prohibition of dying foods or drinks. There is also no prohibition on the the flesh of a person and therefore it would be permitted to place the oil into the water on Yom Tov.

Rav Yaakov Emden (42) writes that if it is the custom in the city to prohibit this action, it is preferable not to do it. The Chida rules stringently as well.