Shar tos (clarified butter)

What it is

Shar tos, literally "yellow butter" or "yellow oil", is Mongolian clarified butter: pure butterfat separated from the water and milk solids in cream. It is similar in principle to Indian ghee. Because almost all the water has been removed, shar tos keeps far longer than fresh butter, and herding families store it through the winter as a concentrated source of energy when fresh milk is scarce.

It sits near the end of a chain of dairy products. Milk is heated to make öröm (clotted cream) or skimmed for cream; the cream is churned into tsagaan tos, "white butter"; and white butter is gently melted to separate the clear yellow fat.

How it is made

The butter or cream is melted slowly over low heat. As it warms, the water evaporates and the milk solids separate from the fat. The cook pours or strains off the clear golden liquid, which sets to a firm, yellow fat as it cools. The solids left behind in the pot, slightly browned and tasting of toasted milk, are not thrown away: they are eaten, traditionally mixed with sugar and fried millet.

Families store shar tos in containers in a cool place. In the past, dairy fats were also kept in wooden casks or cleaned animal stomachs, which preserved them through the winter.

How it is used and where to find it

Shar tos is a cooking fat, a flavouring and a ritual substance all at once:

• A spoonful is often added to milk tea, especially for a richer festive brew in which flour is first toasted in the fat.
• It is used in baking and frying, including boortsog and other pastries.
• It fuels the small offering lamps placed on household altars.
• It adds calories to winter meals, when herders work outdoors in severe cold.

You will most often meet shar tos without seeing it: in the richer milk tea served in winter, in boortsog, or in pastries made for Tsagaan Sar. In the countryside, ask your hosts whether they make their own; it is part of the summer and autumn work of turning surplus milk and cream into foods that will last.

Etiquette and tips

• If your host adds a spoonful of shar tos to your tea, it is a gesture of generosity. Taste it before declining.
• Dairy foods are treated with respect in a herding household, so avoid wasting or spilling them.
• Shar tos is very rich, so a little goes a long way.