There is a Halacha requiring one to wash his hands before eating a food that has on it one of the seven Halachic liquids, which include water, milk, oil and others. Among the questions that arise concerning this Halacha relates to a donut that has been saturated in oil to the point where the surface of the donut is moist. We might, at first glance, require one to wash his hands before eating such a donut, given that he eats a food moistened with oil, which is one of the seven Halachic liquids.
In truth, however, the only oil which is included among the "seven liquids" is olive oil. Obviously, donuts are not customarily fried in olive oil, and therefore one is not required to wash his hands before eating an oily donut.
Must one wash his hands before eating vegetable soup? Vegetable soup is, after all, vegetables in water, which would seemingly require washing. However, the Halacha requiring hand washing applies only if one eats the moistened food with his hands. Vegetable soup, of course, is eaten with a spoon, and therefore one does not have to wash his hands. Furthermore, this requirement does not apply if the liquid has been cooked. Vegetable soup is boiled before it is served, and for this reason, too, one is not required to wash his hands before eating vegetable soup.
Hacham Ovadia Yosef ruled that one is required to wash his hands only if he eats a Kezayit of food with liquid. Therefore, if one eats a small piece of cake dipped in coffee, and the piece is less than a Kezayit, he does not have to wash his hands before eating the cake.
One is not required to wash before eating cereal in milk. Even though milk is included among the seven liquids, the milk we purchase today is pasteurized, and the milk has thus been boiled before it is consumed. As mentioned earlier, the requirement to wash before eating moist food does not apply if the liquid has been boiled, and therefore one does not have to wash before eating food dipped in milk. Furthermore, as mentioned, this requirement applies only if one eats with his hands, and cereal is eaten with a spoon.
The Mishna Berura (Rav Yisrael Meir Kagan of Radin, 1839-1933) cites an opinion that equates salt with water for the purposes of this Halacha. Since salt is produced from water, this view contends, it must be treated like water, and thus one must wash before partaking of any food dipped in salt. However, Halacha does not follow this opinion, and one therefore is not required to wash his hands before eating a food dipped in salt.
Butter that has melted and become a sauce is considered a liquid for the purposes of this Halacha. Therefore, if a person dips crackers, vegetables or other foods into melted butter, then he must first wash his hands before eating.
Summary: Generally speaking, one must wash his hands before eating a Kezayit or more of food moistened with or dipped into liquids such as water, milk and olive oil. There are, however, several exceptions to this rule, including vegetable soup and cereal with milk, which do not require hand washing. One must wash before eating food dipped in melted butter.
