Grass-fed beef is usually leaner, so it is best to cook it at a slightly lower temperature.
Lower the cooking temperature because grass-fed beef is leaner than it’s grain-fed counterpart, you need to cook at a lower temperature and for less time to preserve the moisture in the meat.
Invest in a meat thermometer. A meat thermometer will ensure that you cook your meat just the way you like it.
The desired internal temperature for grass-fed beef is as follows:
Rare - 120 degrees F
Medium Rare - 125 degrees F
Medium - 130 degrees F
Medium Well - 135 degrees F