Tevul Yom 2:2-3

T’vul Yom 2:2

Let’s say there was a pot full of liquid and a t’vul yom touched it. If the liquid was trumah, it’s invalidated but the pot remains clean; if the liquid is secular (chulin) then everything remains clean. If his hands were ritually unclean, then everything is rendered unclean. This is a case where hands are treated more stringently than a t’vul yom. A t’vul yom is treated more stringently than hands in that a doubtful t’vul yom invalidates trumah, but doubts involving hands are ruled to be clean.

T’vul Yom 2:3

Let’s say that a thick stew was made of trumah but the garlic or oil in it was chulin. If a t’vul yom touches part of the garlic or oil, he invalidates the whole dish. If the stew was of chulin and the garlic or oil in it was trumah and a t’vul yom touched part of them, then he only invalidates the part that he touched. If the major part of the dish was garlic then we follow the majority. Rabbi Yehuda said that this is only the case when the garlic is a mass in the pot but if it was scattered in the mortar, then it remains clean because he desired it to be scattered (and therefore it's not a connective). The same is true for all other mashed foods that are mashed with liquids. If a food is usually mashed with a liquid but in this case it was mashed without a liquid, then it is treated like a cake of pressed figs even if it formed a mass in the pot (i.e., touching part doesn’t render the entirety unclean).