Terumos10: 2
תַּפּוּחַ שֶׁרִסְּקוֹ וּנְתָנוֹ לְתוֹךְ עִסָּה וְחִמְּצָהּ, הֲרֵי זוֹ אֲסוּרָה. שְׂעוֹרִים שֶׁנָּפְלוּ לְתוֹךְ הַבּוֹר שֶׁל מַיִם, אַף עַל פִּי שֶׁהִבְאִישׁוּ, מֵימָיו מֻתָּרִין.
[If] one crushed an apple and placed it into dough and it leavened it, this is forbidden. [If] barley fell into a pit of water, even though [its waters] were spoiled, its waters are permitted.