Gandalf seems to be wearing the same grey robes all the time*. Through rain and snow, while he rides, while he smokes, he is, as his name moniker suggests, wearing grey. In addition, hygiene in medieval times is generally suspect to say the least...
So with all he goes through does Gandalf carry an odor/smell about him or since he is also a Maiar does his magic/deity status prevent this from happening?
*Yes, I am aware his robes do become white at a certain point... this would be prior to that.
In some linguistic notes (circa 1967) about the elvish root √PHAN "cover, screen, veil", Tolkien digresses a little bit to discuss how the Valar and Maiar appeared when not adopting a physical raiment. He says that Maiar had recognizable smells even when invisible.
In QUENYA, owing to close relations of the Eldar in Valinor with the Valar. and other lesser spirits of their order, fana developed a special sense. It was applied to the visible bodily forms adopted by these spirits, when they took up their abode on Earth, as the normal "raiment" of their otherwise invisible being. In these fanar they were seen and known by the Eldar, to whom glimpses of other and more awe-inspiring manifestations were seldom given. But the Elves of Valinor asserted that unclad and unveiled the Valar were perceived by some among them as lights (of different hues) which their eyes could not tolerate; whereas the Maiar were usually invisible unclad, but their presence was revealed by their fragrance.†
†This applied only to those uncorrupted. Melkor, they said, was invisible, and his presence was revealed only by great dread and by a darkness that dimmed or blotted out the light and hues of all things near him. The Maiar corrupted by him stank. For this reason neither he nor any of the evil Maiar ever approached one of the Eldar that they wished to persuade or deceive except clad in their fanar. These they could still make to appear beautiful to Elvish eyes, if they wished - until after the great treachery of Melkor and the destruction of the Trees. After that Melkor (Morgoth) and his servants were perceived as forms of evil and enemies undisguised.
Parma Eldlamberon #17, page 175
These notes were placed in a cardboard folder which Tolkien labeled "PHAN, MBAR, BAL and other Elvish etymologies". Along with other such linguistic notes, these were edited by Christopher Gilson and published in 2007 in Parma Eldlamberon #17, to accompany the publication of Tolkien's unfinished "Words, Phrases, and Passages in Various Tongues in The Lord of the Rings".
I bow to Ibid's wonderfully sourced answer which addresses how Gandalf smells in-universe.
For the record, the individual portraying Gandalf in the (2001-2003) film series is described as smelling very pleasantly like incense and tobacco.
Q. What does Sir Ian Mckellen (Gandalf) smell like?
EW: He smells really good! He smells of a sort of masculine incense. I just…I can't put my finger on specifically what notes of the scent are there, but there's something very pleasant about the way that he smells. Incense definitely comes to mind. What an interesting question.
Q. And Old Toby
EW: That was great.
Ibid's gives a good description of how bodies work for the Valar and Maiar — they are naturally incorporeal beings who can inhabit and disinhabit corporeal bodies as easily as we put on and take off clothes. They do this mainly for self-expression and to interact with the world more easily.
The Istari (wizards) did something different. They were Maiar, but they were actually incarnated by the Valar.
For with the consent of Eru they sent members of their own high order, but clad in bodies as of Men, real and not feigned, but subject to the fears and pains and weariness of earth, able to hunger and thirst and be slain; though because of their noble spirits they did not die, and aged only by the cares and labours of many long years.
— “The Istari,” Unfinished Tales
So Gandalf and the other wizards were not “wearing” bodies like other Maia, but were actually embodied like any man or elf. So then I suspect they smell like any man or elf — probably pretty rank, knowing Gandalf's penchant for traveling in the wilderness. I don't think Gandalf's “noble spirit” acted as deodorant, even if it did prevent him dying of old age.
