Usak Tarhana Product Description and Distinguishing Features: Tarhana is a traditional fermented food commonly enjoyed throughout Turkey, made by fermenting a dough consisting of wheat flour, yogurt, a variety of vegetables, and spices, which is then dried and ground into a powder. The distinctive reputation of Uşak Tarhana stems from the province’s unique climatic conditions, which result in a cooler fermentation temperature and extended fermentation period. This allows for a richer diversity of microorganisms that enhance the fermentation process, producing a more intense flavor. Moreover, the generous use of red pepper in Uşak’s tarhana, more than in other regions, contributes to its appealing and characteristic taste. For these reasons, Uşak Tarhana holds a geographical indication status, requiring that all stages of production occur within the borders of Uşak province. Uşak Tarhana is a granular style of tarhana made by fermenting a blend of wheat flour, full-fat yogurt, red pepper, onion, tomato, and mint for a minimum of 21 days. After fermentation, the dough is spread thinly on a clean cloth, gradually reduced in size, and dried in the shade. This tarhana can be used in its dried form or stored as dough under refrigeration or freezing conditions. The unique flavor of Uşak Tarhana compared to other types is attributed to factors such as the extended fermentation period conducted under the natural climate of Uşak and the generous amount of vegetables (red pepper, onion, and tomato) incorporated during preparation. While in many regions fermentation completes within a week, Uşak Tarhana undergoes a longer 21-day fermentation. Locals traditionally believe that fermentation is finished only after the dough rises and falls twice. The prolonged fermentation process is closely tied to the natural climatic conditions of Uşak province, which features a transitional climate between the Aegean and Central Anatolian zones. Production typically begins in the last week of August and continues until the end of September, during which the average temperature hovers around 22°C with relative humidity near 60%. This specific temperature range is vital for developing various compounds that give Uşak Tarhana its distinct taste and aroma. The microflora present in Uşak Tarhana primarily consists of lactic acid bacteria such as Lactobacillus plantarum and Lactobacillus brevis, along with the distinctive strain Lactobacillus alimentarius. Yeasts like Saccharomyces cerevisiae and Pichia kudriavzevii are also part of the fermentation. This long fermentation process contributes to the release of beneficial proteins that may support human health by boosting the immune system and helping regulate blood pressure. Furthermore, scientific research has revealed that certain lactic acid bacteria present in the microflora of Uşak Tarhana produce bacteriocins, which exhibit antimicrobial effects against harmful bacteria. Another notable characteristic of Uşak Tarhana is the abundance of ingredients used, especially the generous amount of vegetables, which not only enhance the taste and aroma but also support the proliferation of beneficial microorganisms during fermentation. As illustrated in Table 1, the vegetable content in Uşak Tarhana production reaches a high proportion of 42%, exceeding that of tarhana from other Turkish regions. Additionally, a factor that contributes to the diversity of advantageous microbes is the omission of vegetable cooking in the dough preparation process—a step that is common elsewhere but skipped in Uşak to maintain the beneficial microorganisms naturally present on the vegetables. Another unique aspect of Uşak Tarhana is its preparation through an extended fermentation period of 21 days under the distinctive climatic conditions of Uşak, combined with the prominent use of Sivaslı Pepper, cultivated in the Sivaslı district of Uşak. Production Method: The ingredients and their quantities used in making Uşak Tarhana are detailed in Table 1. The recipe calls for whole wheat flour (complying with the Turkish Food Codex Wheat Flour Regulation, No: 2013/9) and full-fat yogurt (with fat content above 3.8%, according to the Turkish Food Codex Fermented Dairy Products Regulation, No: 2009/25). In addition, only high-quality, defect-free red pepper suitable for tarhana, onions, tomato paste-grade tomatoes, and dried mint free from mycotoxins and pesticides (with moisture below 10%) are used. For the red pepper component in Uşak Tarhana, the Capsicum annum L. cv. Kapya variety is utilized. To add a mild spicy note, the Sivaslı Pepper (also called "üç burun"), grown in the Sivaslı district of Uşak and known for its low moisture content and vibrant green color, is incorporated. The production steps of Uşak Tarhana are outlined in Figure-2. The initial phase involves preparing the mixture: fresh tomatoes, red pepper, onions, and dried mint are finely ground, after which full-fat yogurt is added. This blend, locally referred to as "tarhana ezesi," is left to ferment at room temperature (around 22°C) for one day. Next, pre-prepared sourdough and wheat flour are incorporated, and the dough is kneaded until it reaches a soft texture, reminiscent of an earlobe. The dough is then covered with a clean cloth and left to ferment again at room temperature (22°C) for a period of 21 days. Locals observe that fermentation completes when the dough rises and falls twice. The fermentation process plays a vital role in defining the quality and unique properties of the product, as the beneficial microorganisms—including lactic acid bacteria and yeast—utilize available carbon and nitrogen sources to produce lactic acid and various aromatic compounds. To prevent the dough from overflowing during fermentation, it is regularly pressed and mixed to introduce air. By the end of fermentation, the dough’s initial pH, typically between 4.5 and 5.0, drops to approximately 3.7. Furthermore, the acidity level—expressed as ethyl alcohol content—should range between 10 and 35. To measure acidity, 10 grams of tarhana (accurate to 0.01 g) is placed into an Erlenmeyer flask—a tall, narrow glass vessel commonly used for boiling, stirring, and titration where evaporation must be minimized. Then, 50 mL of ethanol at 20°C is added. The flask is sealed and shaken vigorously for 5 minutes, after which the mixture is filtered through filter paper. From the filtrate, 10 mL is taken and diluted with distilled water until the color changes. A few drops of phenolphthalein indicator are added until a persistent pink hue appears, and the solution is titrated with 0.1 N sodium hydroxide. The volume of sodium hydroxide used is multiplied by 5 to determine the acidity of the tarhana. Following 21 days of fermentation, the flavored dough is divided into smaller portions and spread out on a clean cloth to dry in the shade. These pieces are progressively reduced in size each day to accelerate and improve drying. The final step involves grinding, where the dried tarhana dough is manually rubbed to achieve a fine consistency. The ground tarhana is then sifted through a sieve to remove any large particles. The moisture content of Uşak Tarhana must be reduced below 10%. Lastly, the granulated tarhana is packed into cloth bags of desired sizes and stored in cool conditions. Commercial production can also follow these traditional methods using stainless steel tools and equipment.