The boiled drinking water (100oC) is brought to the right temperature with the yeast to work as 10 - 15oC. This temperature will depend on the sort of yeast and the sort of beer. We actually wrote a whole tutorial about browsing in Ho Chi Minh Town that you need https://sai-gon71593.bloginwi.com/61902359/the-2-minute-rule-for-sai-gon