For meal prep, store the cooled egg muffins in an airtight container in the refrigerator for up to 5 days or freeze them for up to 2 months. Reheat in the microwave for 30 to 60 seconds or in a 350°F oven for about 10 minutes until warmed through. To keep carbs low, stick with sugar-free sausage and measure higher carb vegetables like bell pepper and onion carefully. Each muffin is designed to stay around 2 to 3 grams of net carbs, making this recipe ideal for strict keto plans.