Kosher (literally "ritually acceptable") foos are those that conform to Jewish dietary laws. Reasons for food being considered non-kosher include the presence of ingredients derived from non-kosher animals or from kosher animals that were not properly slaughtered, a mixture of meat and milk, wine or grape juice (and their derivatives) produced by gentiles, the use of produce from Israel that has not been tithed properly, or even the use of cooking utensils and machinery which had previously been used for non-kosher food. For an in-depth discussion of this tradition, see kashrut.