The Mongol invasion of Iran in the thirteenth century, followed by the establishment of the Mongol Empire and later the Timurid Empire, brought significant changes to Iran that were not limited to changing the political borders. Increased connections between Iran and Central Asia also contributed to greater commercial and cultural exchange. Increased connections between Iran and Central Asia also contributed to greater commercial and cultural exchange. Some Central Asian and East Asian cooking methods and ingredients entered the Iranian plateau and combined with local traditions. One change associated with this period is the popularity of noodles and dumplings in Iranian cuisine (Fragner, 1987). Although no precise historical evidence shows that the preparation of āsh reshteh began during this period, sources that associate the introduction of noodles to Iran with this era make this a plausible hypothesis.

The works of Besshaq At‘ema Shirazi, a fifteenth-century poet, are important sources for understanding the food culture of this period. His poems are not cookbooks in the strict sense, but their extensive use of food names, ingredients, and terms related to eating and cooking provides valuable information about the culinary culture of his time. These works show that foods based on flour, dough, and grains, as well as different types of ash and noodle dishes, were known in Iranian food culture during that period (Ghanoonparvar, 1993), (Matthee, 2016). However, modern ash-e reshteh, including its Ingredients and cooking methods, has changed over time.

Qajar-period written sources provide a much broader picture of the variety of ash. Kārnāmeh-ye khorāk, written by Nader Mirza Qajar, records many types of ash prepared with combinations of herbs, grains, and legumes, together with ingredients such as sour grape juice, pomegranate, sumac, mung beans, kashk, noodles, milk, and eggplant (Nader Mirza Qajar, 19th century). This variety shows that by the nineteenth century, ash reshteh had already developed.

Ash also appears in many Persian proverbs and expressions, and sources on popular culture have recorded this widespread use (Eilers, Elahi, & Boyce, 1987). For example, “It is the same ash and the same bowl” is used when circumstances remain unchanged despite expectations of improvement. “Hotter than the ash” describes someone who shows more sensitivity about an issue than the person directly involved. “Having a burned mouth without having eaten the ash” refers to a situation in which someone suffers responsibility or negative consequences without receiving any benefit. The proverb “When there are two cooks, the ash becomes either too salty or tasteless” expresses the problems caused by having too many decision-makers.  The presence of one food in such varied linguistic contexts shows that ash has become a familiar part of everyday experience and Persian-speaking popular culture.

Āsh reshteh is one of the clearest examples of how food in Iran has rarely been just about nourishment. Among Iran's Zoroastrian communities, for instance, certain types of āsh have long been tied to specific festivals rather than everyday eating. Ethnographic work on villages around Yazd describes how āsh was cooked for sacred days such as Mehregan, with each family customarily bringing a portion of the raw ingredients, wheat, lentils, chickpeas, whatever they could contribute, all of which was then cooked together in large pots at the fire temple and shared out among the whole community (Eilers, Elahi, & Boyce, 1987). Preparing āsh this way was a symbolic act. It’s a way of enacting solidarity and cooperation among people, and the dish was part of how the festival was marked and experienced together.

A similar logic runs through āsh-e posht-e pā, which literally means “behind-the-foot ash,”. The dish is prepared a few days after a family member leaves on a journey so that the trip will be safe, a custom documented as part of the broader repertoire of āsh associated with life events (Eilers et al., 1987). In it, the food becomes a way to channel a family's private worry into something the neighbors share as well. Other varieties of āsh still served a more explicitly ritual purpose, cooked to ward off misfortune, to pray for someone to recover from illness, or to hope a wish fulfilled (Eilers et al., 1987).

āsh-e Nazri is another way of serving ash reshteh. In this context, the dish offered as a religious vow holds a particularly central place within this tradition, and part of the reason may lie simply in how it is made. Because ash is a kind of food that can be prepared on a large scale in one pot, it does not require many cooking facilities. Second is the collaboration in preparing the dish mentioned earlier that gives the activity social weight (Vejdani, 2026).

Even how āsh looked on the surface matters. The design made with fried onion, mint, kashk, or saffron on the surface is not just decoration. In votive contexts, they could spell out the name of a shrine or a short prayer, turning the plate itself into part of the ritual (Eilers et al., 1987).

This kind of votive āsh was not limited to ordinary people. Historical evidence describes an āsh-pazān (cooking āsh) ceremony held at the court of Naser al-Din Shah, the fourth Qajar king, where princes, nobles, and ministers were invited to a summer residence near Tehran to take part in preparing āsh reshteh, all carried out with considerable ceremony. Different stories are told about how this tradition began. In one, Naser al-Din Shah's mother, Mahd-e Olya, vowed as a young mother to prepare āsh for her son's health, a vow she renewed every spring, and one the Shah is said to have carried on himself once he took the throne. In another version, the Shah made the vow himself during an outbreak of cholera, promising to cook āsh every year if he survived. Once cooked, the āsh was ladled into bowls of different sizes and handed out according to each guest's rank, and every guest was expected to return their bowl filled with gold coins as a gift to the Shah. In this ceremony, āsh was therefore more than an ordinary food. The preparation process carried a spiritual and votive meaning associated with health, while the way the food was served reflected an individual’s position in relation to the Shah, and finally, the gold gifting expressed loyalty and respect toward the king.

Ash reshteh was also present in urban life. A photograph from the late Qajar period in the A. P. H. Hotz collection at Leiden University Library shows a man who was probably an ash seller. Alongside written sources, this visual evidence suggests that ash was part of Iran’s urban and street-food culture as well as its domestic and courtly food traditions (Matthee, 2016).