Why is the sausage sour?
Because it is made by fermenting pork and rice. It is a sausage enjoyed for the sourness that comes from fermentation, and how sour it is depends on the product and the cooking.
Sai Krok Isan · ไส้กรอกอีสาน
If you would like to taste Isan’s sour fermented food, try sai krok Isan. It is a sausage of pork, rice, garlic and other ingredients that has been fermented. The richness of the meat is joined by a sourness that comes from fermentation. If you have tried sai ua, the northern sausage, you could compare the two.

It is defined by the richness of pork and a sourness from fermentation. How sour it is depends on the degree of fermentation and how it is cooked. The raw chillies served with it can be hot, so try them separately, a little at a time.
Try the raw chillies served with it separately, a little at a time.
Sai krok Isan is an Isan dish made by fermenting pork and rice. It is not food eaten only in Khon Kaen. Compared with the herby northern sai ua, it shows how the ingredients and flavour of a sausage differ from region to region.
Because it is made by fermenting pork and rice. It is a sausage enjoyed for the sourness that comes from fermentation, and how sour it is depends on the product and the cooking.
Sai ua is a northern sausage with herbs, grilled, while sai krok Isan is an Isan sausage of fermented pork and rice. Trying both lets you compare the herb aroma and the fermented sourness.
If you would like to read more about the food and the regions behind it, these sources are worth a look. Ingredients and cooking methods can vary from one cook to the next.
Sharing image credit: Takeaway · CC BY-SA 3.0