the slow cooker and saw these weird white stringy things poking out of the meat

Parasites in beef are incredibly rare, especially in countries with strict food safety regulations. Moreover, parasites typically do not survive the cooking process, particularly at the temperatures used in slow cooking. If you’ve cooked your meat to the appropriate internal temperature, it’s very unlikely that any parasites could have survived.

2. Understanding Muscle Fibers and Connective Tissue in Beef
Muscle fibers and connective tissues are integral parts of any cut of meat. Muscle fibers are the actual “meat” portion of the muscle, while connective tissues hold these fibers together and attach muscles to bones. Beef contains a significant amount of connective tissue, which is largely composed of collagen.

When these tissues are cooked—especially in a slow cooker—the collagen can become gelatinous and appear as white, stringy bits. This is particularly noticeable in cuts like chuck roast or brisket, which are known for their high connective tissue content. These stringy appearances are a natural result of the cooking process and are not indicative of spoilage or infestation