Ayran is a popular drink of water and yoghurt not unlike the Finnish/Russian buttermilk or Indian lassi, but always served without sugar (and, in fact, typically with a little salt added). A version loved by the locals köpüklü ayran is a delicacy if you're travelling by bus over the Toros (Taurus) Mountains. Ask for yayık ayranı or köpüklü ayran.
Turkish coffee (kahve), served in tiny cups, is strong and tasty, just be careful not to drink the slugdy grounds at the bottom of the cup. It is much different than the so called Turkish coffees sold abroad. Sade kahve is served black, while as şekerli, orta şekerli and çok şekerli will get you a little, some or a lot of sugar in your cup.
Instant coffees, cappuccinos and espressos are gaining more popularity day by day, and can be found with many different flavours.
Tea (çay) is also very popular in the country. Be careful, if your tea is prepared by locals, it can be much stronger than you're used to. Although it is not native-typical and a rather touristic feature, you have to taste the special apple tea (elma çayı) or island tea (adaçayı) ( sage )of Turkey!
Boza is a traditional cold, thick drink that originates from Central Asia. It is fermented bulgur with sugar and water additions. Vefa Bozacisi is the most known and traditional producer of boza in Istanbul. In Ankara, you get excellent Boza from Akman Boza Salonu in the old city in Ulus. Boza can also be found on the shelves of many supermarkets, especially in winter, packaged in 1-litre PET bottles. However these bottled bozas lack the sourness and consistency of traditional boza, they are sweeter and less dense.
Sahlep is another traditional hot drink, made from milk, orchid root and sugar, typically decorated with cinnamon. It is mostly preferred in winter and can be found in cafes and patisseries (pastane). You can also find instant sahlep in many supermarkets sold with the name Hazır Sahlep.
Red Poppy Syrup is one of the traditional turkish drinks made of red poppy petals, water and sugar by natural ways. Bozcaada is famous with red poppy syrup.
International brands of colas, sodas and fruit-flavoured sodas are readily available and much consumed alongside some local brands. Please note, in Turkish, soda means mineral water, whereas what is called as soda in English is gazoz or sade gazoz in Turkish.
While the significant proportion of the Turks are Muslims, alcoholic beverages are legal, widely available, and thoroughly enjoyed by the locals. The local firewater of choice is rakı, an anise-flavoured liquor double distilled from fermented grape skin. It is usually mixed with water and drunk with another glass of iced water to accompany it. You may order 'tek' (single) or 'duble' (double) to indicate the amount of rakı in your glass. Rakı is a national drink which Turks like to make foreigners taste. Make sure to try it but don't overindulge as it is very potent! Remember not to mix it with anything else. There is a wide selection of different types in supermarkets. Mey, and Efe Rakı are two of the biggest producers. Only the connaisseurs know which type is the best. Yeni Rakı which is a decent variety has the wıdest distribution and consumption.
As for Turkish wine, the wines are as good as the local grape varieties. Kalecik Karası from Ankara, Karasakız from Bozcaada, Öküzgözü from Elmalı, Boğazkere from Diyarbakır are some of the most well-known varieties. The biggest winemakers are Kavaklıdere, Doluca, Sevilen, and Kayra with many good local vineyards especially in the Western part of the country. In addition liquory fruit wines of Şirince in İzmir are well worth tasting. One specific sweet red wine to try while you're there is Talay Kuntra.
There are two major Turkish breweries. Efes and Tekel Birası are two widely known lagers. In addition, you can find locally brewed Tuborg, Miller, Heineken and Carlsberg too.