Reference for Pesachim 220:15
אמר רב יהודה אמר שמואל כל המזוג מצטרף
R'Joseph said: Two [cups] of wine and one of beer do not combine; two of beer and one of wine combine, and your token [is this]: 'This is the general principle: Whatever is joined thereto of a material more stringent than itself is unclean; of a material more lenient than itself, is clean.'<span class="x" onmousemove="('comment',' Materials, to become unclean, must be of a certain minimum size, which varies according to the value of the material: the greater the value, the more stringent it is, i.e., the smaller its minimum. If the material is less than the minimum and a piece of another material is joined to it, making it up to the minimum, the rule is as stated. Thus here too, wine, being more valuable than beer, combines with it; beer being less valuable than wine, it is disregarded.');"><sup>17</sup></span> R'Nahman said in Rab's name: Two [cups] before the meal<span class="x" onmousemove="('comment',' Lit., 'tray.'');"><sup>18</sup></span> and one during the meal combine; one before the meal and two during the meal do not combine. R'Mesharsheya demurred: Do we then desire to effect a remedy for the meal: we desire to effect a remedy for the person, and surely the person stands remedied!<span class="x" onmousemove="('comment',' Since he has drunk three.');"><sup>19</sup></span> Yet all agree that two during the meal and one after the meal do not combine, in accordance with the story of Rabbah B'Nahmani.<span class="x" onmousemove="('comment',' V. B.M. 86a.');"><sup>20</sup></span> Rab Judah said in Samuel's name: All mixed drinks combine,<span class="x" onmousemove="('comment',' If a man drinks mixed (i.e., diluted) wine and then any other mixed drink (so Rashbam) , they combine.');"><sup>21</sup></span>