Maran writes in Shulhan Aruch (Orah Haim 4) that one must ensure not to touch a vat of beer in the morning before washing Netilat Yadayim, as doing so could cause one to lose the beer. The Mishna Berura (Rav Yisrael Meir Kagan, 1839-1933) explains that since there is Tum'a (impurity) on one's hands when he wakes up in the morning, touching food can cause it to become Tameh, which can have detrimental effects. One must therefore avoid touching food before washing his hands in the morning. The Halachic authorities write that if one did touch food before washing his hands in the morning, he should put it under water three times, and then it may be eaten. This applies even to vegetables that one normally peels, like cucumbers. Despite the fact that one touched only the peel, which in any event will be removed, the vegetable must be rinsed three times before it is eaten. Some writers raised the question of why this method of eliminating Tum'a does not work in the case of garlic that was left without its peel overnight. The garlic in this case should not be eaten, as it contracts Tum'a overnight, and the Poskim do not offer the solution of rinsing the garlic the three times. The work Arsot Haim explains that one cannot compare different forms of Tum'a and evil spirits. A method that is effective for eliminating one kind of Tum'a is not necessarily effective with regard to a different kind, and thus although a food that has been touched before Netilat Yadayim may be rinsed and eaten, this solution cannot be used in the case of garlic that had been left overnight without its peel. The Mishna Berura writes that one should also refrain from smelling tobacco snuff before washing Netilat Yadayim in the morning, for two reasons: 1) he causes the snuff to become Tameh by touching it; 2) smelling snuff involves touching the nostril, and it is forbidden to touch the openings of one's body before washing Netilat Yadayim. Summary: One should ensure not to touch any food or drink before washing his hands in the morning. If he did touch food before washing his hands, he should wash it three times and it may then be eaten.