# Microbiological and Sensory Quality of Artisanal Sour Cream
## 1 Introduction  
Sour cream is a dairy product consisting of concentrated milk fat, in which the fat globules are protected by a surrounding membrane [1]. It is widely appreciated for its richtaste and is consumed on its own, often paired with other dairy products such as fresh cow's milk cheese, or used as an ingredient in various culinary dishes and in butter production. Today, there is a wide range of dairy products on the market, with cheese (including fresh, soft, smoked, and hard varieties), milk, and sour cream being among the most common. Traditionally, in Croatian marketplaces, small-scale producers sell artisanal sour cream in plastic containers, plastic bags, or glass jars. However, this type of distribution can negatively affect product quality, as the cream is exposed to various external conditions throughout the distribution chain, increasing the risk of contamination and spoilage [2]. Artisanal sour cream, in particular, often has a shorter shelf life, mostly due to the absence of adequate heat treatment and sterile conditions during milking, handling, and storage. Unfortunately, there is little publicly available information on the quality of sour cream found in public marketplaces. In Croatia, small-scale dairy processing households must be registered in the Register of Small Agricultural Households and comply with the provisions of the Rulebook on the Registration and Approval of Facilities and on the Registration of Food Business Operators [3] in order to meet the food safety standards set by Regulation (EC) No 852/2004 on the hygiene of foodstuffs. Currently, there are 884 such households registered for the production of fresh cheese and cream in the Republic of Croatia. These households are permitted to process up to 50 litres of milk per day from animals kept on their own farms, which must have brucellosis- and tuberculosis-free herd status. Their products may be sold at the place of production, at markets, as part of tourism offerings, or through direct delivery, provided they comply with the requirements of Regulation (EC) No 852/2004. However, many artisanal dairy products are often sold without proper labelling, often lacking basic information such as name, expiry date, storage instructions, and nutritional composition. Consumers must therefore rely on their own judgement or the advice of vendors when making purchasing decisions. The traditional method of making artisanal sour cream involves the spontaneous fermentation of raw milk at the household level. In the absence of homogenisation, milk fat separates and rises to the surface due to differences in density among milk components, forming sour cream. Its quality depends on several factors, such as the season of production, the microbiological quality of the raw milk, the hygienic conditions, and the skill of the producer [4]. The method of producing sour cream in households is often primitive: freshly milked raw milk is left to ferment at room temperature and the fat layer that forms on the surface is collected. This process, however, can lead to the presence of pathogenic microorganisms, posing potential risks to consumer health [5]. The basic prerequisite for the production of high-quality cream is the use of microbiology clean raw milk and minimizing the time milk is stored at elevated temperatures. When raw milk is of high quality (total bacterial count < 20,000/mL), microbial spoilage in the cream is negligible. In contrast, milk with a high microbial load (total microbial count > 100,000/mL), even when refrigerated, significantly compromises cream quality [6]. Pathogenic microorganisms commonly associated with milk and dairy products include _Staphylococcus aureus_, _Salmonella_ spp., _E. coli_, _L. monocytogenes_, _Y. enterocolitia_, and _Campylobacter_ spp. These pathogens can originate from various sources, including the farm environment, milking equipment, handling personnel, and airborne contamination [2,7,8].