Huyết (congealed blood) can be found in some Huế dishes such as bún bò Huế (Huế styled vermicelli with beef), mì nui (Huế styled rigatoni), or in some cháo (porridge), etc. Huyết is commonly extracted from cow, pig or duck. While Huyết bò (or huyết lợn) the congealed cow’s (or pig’s) blood is thicker, huyết vịt (congealed duck’s blood) is tenderer and more light-colored. Besides, I observe that only the cubes of huyết bò or huyết lợn have holes on them after cooked, huyết vịt does not.
I once talked to a bún bò Huế seller and learnt that many people love huyết because they believe that it helps them to be more persuasive, more fluent and smoother in speaking. Well, of course, it’s not true. It’s just a way to explain why many Huế people are so addicted to the chocolate-colored cubes of boiled huyết.
Although I’m a fan of huyết, I don’t think it is healthy and so I don’t recommend it. To avoid having it in your bún bò Huế, you can tell the seller: “Tôi không thích huyết. Cảm ơn.” (I don’t like congealed blood. Thanks.)