Soak the bought fat sausage in rice soup or rice soup, then turn the casing over from one end of the sausage mouth and tear off the oil and impurities inside. Be careful, because there is a film wrapped in oil, so you can tear off the oil quickly by tearing off that film. Tear off all the grease, rinse it with warm water, add appropriate amount of white vinegar and rub it repeatedly. Rub the intestine skin and intestine, and then the suspended matter in the intestine skin will come out, and then rinse it with clean water.
Then, you can use salt to force the fishy water out, because the pig's large intestine itself has a lot of fishy water and dirt, which can't be washed clean with clean water. Salt itself is highly permeable and can quickly penetrate into the large intestine to dehydrate it, so fishy water and dirt that are difficult to clean in the large intestine of pigs will run out by themselves, and it will be easier to wash it by adding water. This step is very important.
Secondly, edible alkali can be used to soften the meat quality, because the edible alkali itself is very corrosive, so adding edible alkali will help to soften the meat quality of pig large intestine more quickly, and then it will be cleaner and more thorough after cleaning, but generally not too much, so as to avoid the color and taste of the finished product being affected by the smell of heavy alkali.
At this time, the large intestine has been washed almost, but people with high food requirements can add starch and wash it again if they are not at ease. Starch can thoroughly clean the large intestine, because starch itself has strong adsorption. After adding salt and edible alkali to force out enough fishy water and dirt, add a handful of starch with strong adsorption and knead it, which can suck out the blood and dirt in the large intestine more thoroughly and ensure that the finally washed large intestine is white and tasteless.