Maasrot, Chapter Five, Mishnah Six
Temed is a drink made from the grape-skins that have already been pressed to make wine. They would pour water over the grape-skins and they would give some taste to the water. Our mishnah deals with giving tithe from temed. These grape-skins would not have been tithed for because the tithe was taken from the wine, after the grape-skins had already been cast aside.
1) One who makes grape-skin wine, and he put water on by measure, and he finds [afterwards] the same quantity, he is exempt from tithe.
2) Rabbi Judah makes him liable.
3) If he found more than the measure, he must give [tithe] for it from another place, in proportion.
Section one: If after he pours the water onto the grape-skins and then filters them out he finds that the volume of the temed is the same as the volume of the water he added, then the grape-skins have added color and taste but no volume. Therefore, according to the first opinion he is exempt from tithing the temed.
Section two: Rabbi Judah holds that the added taste does make him liable to give tithes from the temed.
Section three: If he finds that the grape-pulp did lead to increased volume, then he must give tithes. The mishnah recommends that he give tithes from other untithed produce. When he does so, he gives it according to the proportion of the increase that the grape-pulp caused in the water. For instance, if he found a one liter increase, he must separate tithes for one liter of grapes. He would end up giving 100 ml of tithe from other wine. However, if he gives from the temed itself, he must separate for all of the temed in order to tithe for all of the wine in the temed. Thus if there was 10 liters of water which increased to 11 liters, he would have to give 1.1 liters of the temed as tithe, in order to account for 10 per cent of the wine in the temed.