Should I use "馬乳酒", "クミス", or "アイラグ" for fermented mare's milk?

Question

Which word should I use for fermented mare's milk (Japanese wikipedia, English Wikipedia)?

馬乳酒 represents the kanji form, literally "horse milk alcoholic beverage", while "クミス" is gairaigo based on what most languages call it ("kumis"), and "アイラグ" is based on what Mongolians call it ("airag").

Which form should I use? The kanji form has the advantage of being easily understood when written down, and it was the form used by Wikipedia, but I don't know when to use kanji, and when to use katakana. Also, does Japan have closer ties with Mongolia than with other central Asian countries like Kazakhstan, meaning that it's more likely to use アイラグ than クミス?

Answer 1

If you are generally referring to fermented mare's milk, I'll definitely go with 馬乳酒. The katakana form would be appropriate when you are specifically referring to that culture's particular style of fermented mare's milk.

Also, does Japan have closer ties with Mongolia than with other central Asian countries like Kazakhstan

Not really. I'd say Korea and China are the only countries that we have a "special cultural relationship". So for example one might explain ピクルスはキムチみたいなもん or 西洋の餃子. But I guess this is really simply because the foreign word is already widely used, rather than because of close ties. If it's in kanji then words may be used even if they are not widely used yet (e.g. if 馬乳酒 were used in either countries, it can be understood by both).