Post-harvest handling, utilization, marketing and processing practices of traditionally produced buttermilk (Arera) in Sidama Regional State

In the highlands and valleys of Ethiopia, milk is more than just a drink; it is a cornerstone of daily life and a vital source of nutrition for millions. While much of this milk is consumed fresh, a significant portion is transformed into traditional dairy products through natural fermentation, a process that has sustained communities for generations. Among these products, buttermilk holds a special place. It is the liquid left behind after churning milk into butter, a byproduct that is rich in protein and probiotics, offering a refreshing and digestible alternative to the heavier fat content of butter. In many parts of the country, this sour, defatted liquid is not discarded but cherished, consumed alongside staple foods or sold to support household incomes. Yet, despite its importance, the specific ways this product is handled, processed, and sold in the Sidama region have remained largely undocumented, leaving a gap in understanding how small-scale farmers navigate the challenges of keeping this perishable food safe and profitable in a tropical climate.

To fill this gap, researchers from Dilla University, Haramaya University, and other Ethiopian institutions traveled to the Sidama Regional State to observe the daily realities of buttermilk production. They focused on three distinct ecological zones—highlands, midlands, and lowlands—each with its own climate and farming practices. The team interviewed 216 smallholder families, asking detailed questions about their routines, from how they wash their hands and equipment to how they decide when to sell their product. They wanted to understand the entire journey of the buttermilk, known locally as Arera, from the moment milk is collected to the moment it reaches a customer's cup or a local market stall.

The study revealed that the process is deeply rooted in tradition and managed primarily by women. In nearly every household surveyed, the women were the ones responsible for turning fermented milk into butter and separating the buttermilk. This task is physically demanding and time-consuming. On average, the churning process takes about 86 minutes, but this time varies significantly depending on the weather and location. In the cooler highlands, where the milk ferments more slowly, the churning takes over 100 minutes. In the warmer lowlands, the process is faster, finishing in roughly 68 minutes. The researchers found that the temperature of the environment plays a crucial role in how long the milk must sit before it is ready to be churned, with colder climates requiring longer fermentation periods.

Hygiene and the tools used are central to the quality of the final product. The study showed that while most farmers wash their hands before handling the milk, the equipment used is often made of traditional materials like clay pots, calabashes, or plastic containers, rather than modern stainless steel. A unique and widespread practice observed was the smoking of these containers. Before use, farmers smoke the pots and jars with wood chips from specific trees, most commonly the Olea africana, also known as the wild olive. This smoking is not just for cleaning; it imparts a distinct flavor and aroma that consumers prefer, and many believe it helps preserve the milk. The researchers noted that while this traditional method adds character, the lack of standardized, food-grade equipment and the reliance on informal cleaning methods pose challenges for maintaining consistent hygiene.

Once the buttermilk is ready, it faces a race against time. The product has a very short shelf life, lasting only about two days on average before it spoils. In the cooler highlands, it might last three days, but in the hot lowlands, it can go bad in just over a day. This rapid spoilage forces farmers to sell or consume the product almost immediately. Consequently, the market for buttermilk is entirely informal. Farmers sell directly to neighbors, at local markets, or from their own homes. There are no formal supply chains or refrigerated transport systems. The price of the buttermilk fluctuates with the seasons; it sells for an average of 62 Ethiopian Birr per liter during the dry season when supply is lower, but the price drops to about 51 Birr per liter during the wet season when milk production is abundant.

Despite the challenges, the product is a vital source of income, particularly for women, who handle the majority of the marketing. However, the study identified several significant hurdles. The most pressing issue is the seasonality of demand and supply; during the wet season, an oversupply of milk drives prices down, making it difficult for farmers to earn a fair return. Other constraints include the lack of small-scale processing equipment, which makes the churning process slow and labor-intensive, and the limited access to broader markets. The researchers also noted that while the taste of the buttermilk is the most important factor for buyers, the current methods of production do not always guarantee consistent quality or safety, as pathogenic bacteria cannot be detected by taste alone.

The paper concludes that while buttermilk is a cherished and nutritious part of the Sidama diet, its potential is limited by traditional constraints. The heavy reliance on manual labor, the short shelf life of the product, and the lack of modern processing tools mean that the work is difficult and the economic returns are often low. The researchers suggest that to improve the livelihoods of these families and the safety of the food, interventions are needed. These could include providing better, easier-to-clean equipment to reduce churning time, improving the milk yield of local cattle breeds, and developing ways to extend the shelf life of the product. By addressing these specific bottlenecks, the region could transform a traditional byproduct into a more reliable and profitable source of nutrition and income for its people.