Pure alcohol boils at 78.3°C and pure water boils at 100°C. However, boiling a mixture of alcohol and water does not mean that all the alcohol evaporates at 78°C and the remaining water boils at 100°C. In practice, water and alcohol affect each other's boiling points, so the boiling point of a mixture of water and alcohol will be somewhere between 78°C and 100°C. (*Depending on the ratio of water and alcohol.) A mixture of water vapor and alcohol vapor then evaporates together. The exact amount of alcohol left in the pot is not an answer, as there are too many factors. In an experiment, when I made beef stewed in red wine, chicken stewed in red wine, etc. and measured the alcohol content before and after cooking, I found that 4 to 49% of the original alcohol remained in the finished dish, depending on the type of ingredients and the cooking method. This resulted in (Even if red wine is simmered for three and a half hours, about 5% of the total alcohol remains in the dish.) In this way, it is difficult to remove 100% of the alcohol mixed in the food, so there is a technique called 'Nikiri'.