The Chatnut decree extended to beverages, the prohibition limited to the place of sale (במקום מכירתו), settling down to drink (קובע עצמו), the Rama's lenient custom (coffee, tea, beer), wine hidden (יין נסך) in pickles, the price test, רוב / קבוע and the lenient doubt (תלינן לקולא) (Shulchan Aruch, Yoreh De'ah 114 — 12 se'ifim)
שֵׁכָר שֶׁל עוֹבְדֵי כּוֹכָבִים, אַף עַל פִּי שֶׁהוּא עָשׂוּי מִתְּמָרִים אוֹ מִתְּאֵנִים אוֹ מִשְּׂעוֹרִים אוֹ מִדְּבַשׁ, אָסוּר מִשּׁוּם חַתְנוּת; וְלֹא נֶאֱסַר אֶלָּא בִּמְקוֹם מְכִירָתוֹ, אֲבָל אִם הֵבִיא הַשֵּׁכָר לְבֵיתוֹ וְשׁוֹתֵהוּ — מֻתָּר, שֶׁעִיקַּר הַגְּזֵרָה שֶׁמָּא יִסְעַד אֶצְלוֹ.
The beer (שכר) of a non-Jew, even though it is made of dates, figs, barley or honey, is forbidden because of Chatnut (social closeness). But it is forbidden only at the place of its sale ; if one brings the beer home and drinks it, it is permitted, for the root of the decree is “lest one feast with him” (שמא יסעד אצלו).
Shulchan Aruch, Yoreh De'ah 114:1LEVEL 01
Hebrew text of the 12 se'ifim with a fluent English translation. The Chatnut decree on beer, the prohibition at the place of sale, the lenient custom (coffee, tea), the wine hidden in pickles and the price test explained with practical cases.
📖 StudyLEVEL 02
In-depth pilpul: the sugya of Avoda Zara, the Taz's great question (sk4) — why require 60 when סי' קל״ד nullifies wine in water already at שישה? — the מהרי״ט / פנים מאירות debate on the קאווי (PT sk1), שמרים and דבר המעמיד, רוב / קבוע, חקירות and נפקא מינות.
📖 StudyLEVEL 03
Comparative tables (place of sale / one's home, קביעות / עראי, חנות / מן החבית, קבוע / פריש), golden rules, classic pitfalls (price test, בטל בס׳, תלינן לקולא, שמרים) and memorization of the 12 se'ifim.
📖 StudyLEVEL 04
The practical halacha according to the Beit Yosef, Rama, Taz, Shach and Pitchei Teshuva, then the Sephardic poskim (Yabia Omer, Yalkut Yosef, Or LeTzion) and Ashkenazi poskim (Aruch HaShulchan). Note: the Shulchan Aruch HaRav does not deal with this siman — this is a level of psak, not "Daat HaRav".
📖 StudyAccording to the Shulchan Aruch (YD 114:1), the beer (שכר) of a non-Jew — of dates, figs, barley, grain or honey — was forbidden by the Sages as part of the Chatnut decree, out of fear of social closeness (a meal, סעודה). But this prohibition is limited to the place of sale (במקום מכירתו) and only when one settles down to drink (קובע עצמו): taking it home is permitted, and drinking casually in passing (דרך עראי באקראי) is permitted too. The Rama adds that many permit beer of honey and grain, and such is the lenient custom in our lands. This is the principle applied to today's coffee (קאווי), tea and sodas. For its application to your situation, consult your Rav.
Several commercial foods (beer vinegar, juice, honey-drink, capers, olives, fish/טרית, מורייס/garum, spices such as saffron) may have had non-Jewish wine (יין נסך / stam yeinam) added, hence the suspicion. The Shulchan Aruch gives tools: the price test (forbidden if the product is dearer than wine → suspicion that wine was added), בטל בששים (the wine is nullified in sixty times its volume), and the distinction shop (חנות) vs. barrel (מן החבית) — from the barrel there is no fraud, for wine would spoil the barrel. For its application to your situation, consult your Rav.
For foods into which one sometimes puts wine (se'if 10), the Shulchan Aruch forbids them for consumption but permits them for benefit; if all put wine in, it is forbidden even for benefit. The Rama notes this is a rabbinic prohibition: if there is even one non-Jew in town who does not add wine, one buys from all so long as one does not know for certain (תלינן לקולא). If some certainly add and others certainly do not, one follows the majority (כל דפריש מרובא פריש) — but buying directly from them (קבוע) is מחצה על מחצה. For its application to your situation, consult your Rav.