Diet
Like most Vulcans, Spock is a vegetarian. Vulcans are a nonviolent species, which is reflected by their eating habits. This can easily be summed up with a quote from The Logic of Surak (as presented in Diane Duane's Spock's World) which states: "Ideally, do no harm. . . As far as possible, do not kill. Can you return life to what you kill?" This philosophy would most likely imply that Vulcans are not just simply vegetarians, but vegan - a very strict type of vegetarian who consumes no animal products whatsoever. For example, a Vulcan would see no logic in raising an animal to consume its eggs, as that could be considered taking a life.
The first time that Vulcan vegetarianism is established within Star Trek "canon" is in the episode All Our Yesterdays when Spock states, after consuming meat: "I'm behaving disgracefully. I have eaten animal flesh and I've enjoyed it. What is wrong with me?" Perhaps his slip was due to being 5000 years in the past, which would be before the Vulcan "Time of Awakening" or simply because there was nothing else available at the time. It should also be noted that Vulcans do not like to touch their food with their hands if at all possible, although Spock can be seen eating meat with his hands in All Our Yesterdays. A popular Vulcan dish is plomeek soup, first seen in Amok Time.
Generally, Vulcans also do not drink alcoholic beverages. However, there have been a number of occassions where Spock has been known to indulge in one. In the episode The Enterprise Incident, Spock shares a drink, which appears to be Romulan Ale, with the female Romulan commander. In Requiem for Methuselah, he requests Terran Brandy and in the film, The Undiscovered Country, he can be seen once again drinking Romulan Ale at a formal dinner with the Klingons. There is a beverage which is called Vulcan Port, but there is some debate as to whether this wine is exported from Vulcan where its speculated use is in ceremonial practices, or if it is simply just a name. It may even be non-alcoholic. The novelization for The Voyage Home suggests that Vulcans are immune to the effects of alcohol, but become intoxicated upon consuming chocolate.
Some Vulcans have been known to eat replicated meat since it is only patterned after real meat and thus did not require violence to obtain as it is considered artificial. Likewise, some Vulcans may also consume seafood. However both of these facts are debatable, as some have argued that in order to make replicated meat, they must first dematerialize and store actual meat compounds. It must also be pointed out that because Jumbo Vulcan Mollusks are available does not mean that Vulcans themselves eat them. Vulcans may consume meat only in dire circumstances where to do so is the only logical course of action. It is also interesting to note that it is customary for guests of a Vulcan home to prepare meals for their hosts.