Hello, Radiana! While Harshvardhan has given some pertinent references, I think you really should consider doing some qualitative research to find out what Bulgarian consumers of beer look for in a beer brand. Does an individual have a favourite beer brand, and why is that brand favourite? Further, food and drink tastes can be very different in each culture. For example, in my place, we have "strong" beers with a high alcohol content, which is not the norm in many other countries. Talking to some of your friends who are also beer consumers should help you here. We are talking of an emergent design at this stage, that is, you look for answers till you get "saturation", or, till no new answers are coming. 

The “Kingfisher” brand is, for example, a popular beer brand in India. It is positioned on the basis of being a fun, outgoing and energetic brand.

Once you have some beer brand descriptors, you can then check how the brand that you have in mind scores vis-à-vis other competitors on the basis of the descriptors and make a perceptual map. That is one plan you can have for this project.

All the best for your work!

Thank you for the answers and the articles. 

My supervisor told me to see what the consumer thinks is the best of the brand I am reseraching and to see how it reflects on the satisfaction. It it said that the factors of customer satisfaction reflects the attittude towards a brand and if I include the attitude I have to make a research for it too ( which is gonna take me like another 2 months). I was thinking about making a scheme where the satisfaction is a function of expectations and reality and the expectations would be a indicator and the attitude will  be the reality or something like this.

Koleva, I will advise you find Oliver (1980) he provided in depth knowledge on consumer satisfaction. Though his proposition about CSAT is been criticised as what constitutes CSAT in a tangible product (sector) most of the times differred from those in an intangible product sector (services). But I think you can produce a rich dissertation using the qualitative research design perhaps focus group approach whilst adapting constructs by Oliver (1980) and Parasuraman et al (1982; 1983) as ur research lens.