Last night was blind test night . . . grass fed vs. grain fed ribeye steaks (1 1/2" thickness). The conclusion: grass fed tastes more flavorful (deeper flavor) than grain fed but it was tougher. The grass fed is probably tougher due to less intramuscular fat. Both were cooked using a sous vide water bath at 142 degrees (F) for about 6 hours and then seared in a hot cast iron pan with clarified butter and herbs. With the grass fed being tougher, I might try cooking the grass fed an additional 3 hours in the sous vide water bath. My question: Has anyone had difficulty using the sous vide cooking method with grass fed beef? Thanks!