Related for Gittin 3:8
הַמַּנִּיחַ פֵּרוֹת לִהְיוֹת מַפְרִישׁ עֲלֵיהֶן תְּרוּמָה וּמַעַשְׂרוֹת, מָעוֹת לִהְיוֹת מַפְרִישׁ עֲלֵיהֶן מַעֲשֵׂר שֵׁנִי, מַפְרִישׁ עֲלֵיהֶן בְּחֶזְקַת שֶׁהֵן קַיָּמִין. אִם אָבְדוּ, הֲרֵי זֶה חוֹשֵׁשׁ מֵעֵת לְעֵת, דִּבְרֵי רַבִּי אֶלְעָזָר בֶּן שַׁמּוּעַ. רַבִּי יְהוּדָה אוֹמֵר, בִּשְׁלֹשָׁה פְרָקִים בּוֹדְקִין אֶת הַיַּיִן, בְּקָדִים שֶׁל מוֹצָאֵי הֶחָג, וּבְהוֹצָאַת סְמָדַר, וּבִשְׁעַת כְּנִיסַת מַיִם בַּבֹּסֶר:
If one set aside fruits from which to separate terumoth and ma'aseroth [i.e., if he relies upon them and eats other tevel (untithed produce) that he has, saying: Its terumah is in those fruits that I set aside for this purpose], or (if he set aside) money with which to redeem ma'aser sheni, he can proceed on the assumption that they (the set-aside fruits and moneys) are there (in his possession). If they were lost, [If he went to check and found them missing], he must be apprehensive [as to the status of the tevel produce that he had "corrected" through them. And if he had not yet eaten of it, he must tithe it; for it may be that when he said: "Its terumah is in the fruits that I set aside," they were already lost], (he must be apprehensive) for a twenty-four hour period [(retroactively) from the time of checking. When he checked and found them missing, he must suspect that they were already missing yesterday at this time. And if he had made them ma'aser within a twenty-four hour period for other produce, he must tithe it on the possibility (that they were missing.) The rabbis did not require more apprehension than this, relying on the chazakah (the original status, i.e., that they obtained)]. These are the words of R. Elazar b. Shamua. R. Yehudah says: There are three occasions on which wine [which one had set aside for the tithing of other wine] is checked [to see if it had soured (vinegar not being tithable for wine)]: when the east wind blows at the termination of the festival (Succoth), at budding time, and when water enters the boser (half-ripe grapes). [When they are "double-white" they are called "boser," and the entry of water (above) refers to water entering and accumulating within them to the point where some of it is retained. Another interpretation: They would crush grapes when they were boser and add water to prepare vinegar for dipping. The halachah is in accordance with R. Yehudah.]