The beef is too lean, the beef is too old, etc.

1. Beef is too lean: The higher the fat content of beef, the easier it is to become soft and rotten when stewed. If you use lean meat, it will take longer to stew to achieve the same effect.

2. The beef is too old: The beef used is already very old, and it is difficult to stew it even if it is stewed in a pressure cooker. When buying beef, it’s best to choose fresh, tender cuts, such as brisket or sirloin.