Reference for Maasrot 4:1
הַכּוֹבֵשׁ, הַשּׁוֹלֵק, הַמּוֹלֵחַ, חַיָּב. הַמְכַמֵּן בָּאֲדָמָה, פָּטוּר. הַמְטַבֵּל בַּשָּׂדֶה, פָּטוּר. הַפּוֹצֵעַ זֵיתִים שֶׁיֵּצֵא מֵהֶם הַשְּׂרָף, פָּטוּר. הַסּוֹחֵט זֵיתִים עַל בְּשָׂרוֹ, פָּטוּר. אִם סָחַט וְנָתַן לְתוֹךְ יָדוֹ, חַיָּב. הַמְקַפֵּא לְתַבְשִׁיל, פָּטוּר. לִקְדֵרָה, חַיָּב, מִפְּנֵי שֶׁהוּא כְבוֹר קָטָן:
If he pickled, stewed, or salted [produce] in a field, he is required [to tithe]. If he stored [produce] in the ground [in order to warm it up], he is exempt. If he dipped it [while yet] in the field, he is exempt. If he split olives so that the bitter taste may come out of them, he is exempt. If he squeezed olives against his skin, he is exempt. If he squeezed and put [the oil] into his hand, he is required. One who skims [wine] in order to put it in a dish is exempt, but if to put it in an [empty] pot, he is required [to give tithes] for it is like a small vat.