Chhena (Hindustani: [ˈtʃʰeːna]) or chhana (Bengali: [tʃʰana]) is a kind of acid-set cheese originating in the Indian subcontinent that is made from water buffalo[1][2] or cow[2] milk by adding food acids such as lemon juice and calcium lactate instead of rennet and straining out the whey.

[8] Chitra Banerji states that in the life of Krishna, a later manifestation of Vishnu, there is reference to dairy products such as 'milk, butter, ghee and yogurt', but not to chhena.

[9] Catherine Donnelly, author of The Oxford Companion to Cheese (2016), mentions that Vedic literature refers to cheese production made with the aid of barks of palash tree (Butea monosperma), fruits like jujube (Ziziphus mauritiana) and creepers like putika with coagulating enzymes, "as well as Dadhanvat, a cheeselike substance made with and without pores".

According to Catherine Donnelly, these plant substances may have contained rennet-like enzymes and notes that the "Vedas may include some of the earliest known references to rennet-coagulated cheeses".

[10] Lokopakara text dated to the 10th century gives two recipes for coagulated cheeses made from buffalo milk for making sweets using plants and roots.

According to the text, buffalo milk was coagulated using roots of amaranth plant or leaves of marsh barbel (hygrophila auriculata); the soft cheese produced in this manner was called Haluvuga.

Based on texts such as Charaka Samhita, BN Mathur wrote that the earliest evidence of a heat-acid coagulated milk product in India can be traced to 75–300 CE.

[21] Today, some traditional sweet makers such as Annapurna Bhandar in New Delhi continue to make fresh chhena in their stores as a base for their products with locally sourced milk.

[26] Traditional producers of chhena-based products are under pressure from foreign countries such as the United States of America seeking bilateral trade deals with the Indian government, especially as European-style cheeses such as mozzarella become more popular.

[27] Producers argue that they would not be able to compete with international dairy firms as they would have to comply with stricter sanitary and quarantine standards, which would vastly inflate costs of production.

[34] In the case of sweet production, the cheese is drained, kneaded on a wooden board and mixed with sugar and a binding agent such as arrowroot or semolina flour.

[37] The chhena production process can be used to create a bioplastic which presents future innovation opportunities for the technology sector of India.

[28] Three million tonnes of whey[39] is produced each year in the chhena production process and it is typically dumped into the environment, where it is a substantial problem as a pollutant as it has a high amount of organic matter in its mass.

[3] Without adequate cold storage and safe handling, chhena spoils easily due to its high moisture content.

[47] Unsuccessful studies were carried out by Agrawal, Sandey, and Sinha in turning the chhena into powder to preserve it as a dried good and prolong its shelf life, as the reconstituted product was unsuitable for use.

[35] Quality control is a significant issue in India, but food inspectors do not have the power to prosecute those engaging in adulteration of products in the pursuit of increasing profits or selling base ingredients that are below accepted standards.

[46] A study by Maity, Jumar and Misra (2011) found the presence of E. coli in 67% of chhena based sweet samples in Kolkata.