When cooking beef tendons, in the first hour or two of cooking, beef tendon appears as a solid, hard mass that is so tough and chewy that it’s nearly impossible to eat. After four hours of cooking, the collagen breaks down into a silky, soft texture.

As the tendons cool, they coagulate to a more gelatinous state that is slightly chewy but still tender. If you have slow-cooked the tendons over low heat and they don’t appear done, simply continue simmering until the proper texture is achieved.

Unfortunately, if you cook them too fast over high heat, no amount of continued simmering can break down the tough meat.