One of the most appealing things about sous vide is the flexibility that it gives you in dealing with a wide range of culinary situations. In this blog, we’ll walk through two foundational approaches to cooking sous vide, equilibrium cooking and hold-at-temperature cooking, and explain when and why to use each.
You’ll also learn best practices for cooking from frozen, reheating leftovers, and avoiding common mistakes like overcooking or using overly high bath temperatures. Whether you’re after perfect texture, better timing, or safer cooking, this blog will help you fine-tune your technique and build confidence with sous vide.
Equilibrium Cooking
The chemical reactions that transform food from raw to cooked can be very fast; once a critical temperature is reached, the food is essentially cooked, and it does not cook further with more cooking time. The simplest strategy for sous vide cooking is to heat the food until its center reaches the desired temperature, then pull it out of the heat.
This approach works well for tender cuts of red meat, poultry, fish, and other seafood, as well as some fruits and vegetables. Tough meats, many preparations of produce, and most grains and legumes don’t respond well to this treatment because the key chemical reactions responsible for the transformations we call “cooking” take time to happen in these foods.
Equilibrium cooking involves slowly bringing the food’s core to its target temperature. You typically set the bath 1–2 °C (2–3 °F) higher than your desired final temperature to compensate for minor inaccuracies in your thermometer or controller. The slightly hotter bath helps ensure that the food cooks as fully as you want it to. Then you wait for the food’s temperature to stabilize with the bath. It’s the simplest (and in our opinion, the best) approach for cooking sous vide.
Equilibrium cooking is forgiving. You don’t need to obsess over exact timing; food can safely remain in the bath a little longer than the recommended time (within a 10% margin or so) without overcooking. Even irregularly shaped items cook evenly; the cooking time must be long enough for the thicker parts to get done, but the thinner parts aren’t harmed by spending extra time at the target temperature.
It’s a great strategy to use if you’re making complex dishes where components need to stay warm while you prepare other elements. It can be helpful when you’re cooking for holiday meals or dinner parties. You can let components of the recipe sit in the bath until it’s time to assemble them—just set the bath temperature lower than the cooking temperature of the components.
That said, equilibrium cooking can be slow going. Heat flows into the food quickly at first, but slows dramatically during the last part of the cooking process as the temperature difference between the food and the bath narrows. Still, because it’s hands-off cooking, it frees you up for other tasks—and the results are worth it.
Cooking time greatly depends on the thickness of the food. If an ingredient is thinner or thicker than a recipe calls for, timing can be tricky to estimate. A rough rule of thumb is that cooking time is proportional not to the thickness of the food but to the thickness squared. A 2-inch (5 cm) steak, for instance, takes about four times longer to reach medium rare in a water bath than a 1-inch (2.5 cm) steak. For consistent results, we recommend portioning large items before cooking.
Hold-at-Temperature
Cooks in a busy kitchen aren’t always able to pull food from a water bath the moment it reaches a target temperature. Fortunately, most foods can sit at their target temperature for some time without harm. A second approach to sous vide cooking is all about maintaining the food at its target temperature for a fixed amount of time.
Some foods improve from holding, essentially a Modernist version of braising. Like braising, holding meat sous vide can almost magically tenderize tough cuts into melty morsels.
Think of short ribs cooked at 58 °C (136 °F) for 72 hours—they become silky and tender in a way that fast cooking can’t match. The same cut cooked at 82 °C (180 °F) for 10 hours will yield a completely different texture. The mechanism at work here is a chemical process called hydrolysis or denaturing, which breaks down the collagen that holds the muscle together.
While traditional braising is much faster, a tough cut of meat cooked sous vide for 12–96 hours will be much juicier. Its texture, color, and flavor are closer to those of a medium-rare fillet. Our team uses this approach to make otherworldly, melt-in-your-mouth pastrami that cooks low and slow for 72 hours (see page 213 in Volume 3 of Modernist Cuisine).
Holding food at the final cooking temperature has other uses, including pasteurization, aging meats, and softening plant foods. One often needs to hold starchy vegetables, legumes, grains, and other plant-derived foods in a bath for some time to allow water to penetrate the seed coat and soften the core. As with the breakdown of collagen, many variables influence the time needed to age and soften food sous vide. Trial and error is the best way to determine holding times.
You don’t need to be as worried about figuring out how long it’ll take to reach the target core temperature if you’ll be holding food for a very long period of time—say 36 hours. Typically when the bath is set at or near the final core temp, a variation of up to 10% in the holding time makes no noticeable difference. If the holding time is 36 hours, you can give yourself as much as 4 hours’ leeway.
Keep in mind that if you’re planning to cook large items over long periods of time, it’s generally not a good idea to set the bath hotter than the desired final food temperature unless you’re using multiple baths.
Cooking from Frozen
Sous vide is perfect for cooking straight from frozen—no need to thaw. Just drop the frozen bag into the bath and use the equilibrium method, making sure the bath is set to at least 55 °C (131 °F) to avoid any bacterial growth. Keep in mind, cooking from frozen takes considerably longer, so plan accordingly. (Do not try this with an improvised water bath that does not have a heating mechanism.)
After Cooking
Once you get the hang of sous vide, you’ll appreciate it for its convenience as much as its results. With a vacuum sealer and a large bath, you can prep and cook multiple single-portion bags at once. Anything you don’t eat right away can be chilled or frozen for later—and reheating is incredibly simple.
Just remember: food safety matters. Don’t leave food out too long or toss hot bags directly into the fridge. Bacteria thrive in the “danger zone” of 10–50 °C (50–122 °F). Cool your food quickly using an ice-water bath to preserve safety, juiciness, and flavor. Once chilled, store sealed bags in the coldest part of your refrigerator or in the freezer.
Reheating and Leftovers
Reheating sous vide is a game changer. Surprisingly, it takes just as long to reheat food sous vide as it does to cook it from raw using the equilibrium method. So it’s usually not worth precooking tender foods like fish or vegetables. However, for tougher cuts that require long cooking times, reheating is efficient—just bring the food back up to its original core temperature. For red meats, reheat at their initial cooking temperature. For other foods, around 60 °C (140 °F) works well. Avoid reheating above 65 °C (149 °F) to preserve texture and moisture.
Some Common Mistakes
Some chefs opt to use much hotter bath temperatures to speed up cooking. While this works, it also creates steeper temperature gradients within the food, which undercuts two of the biggest perks of sous vide: precision and even doneness. We don’t recommend this approach for home cooks. Instead, stick to your target core temperatures—for example, 50 °C (122 °F) for rare filet mignon, or 53 °C (127 °F) for medium rare—and cook until the deepest part of the food reaches that point.
Tough cuts, like short ribs, need long holds to tenderize. Poultry often requires a hold for food safety reasons, in order to kill potential pathogens and improve the safety of the food. Just be sure your bath temperature is set high enough for pasteurization when needed.
One of the great things about sous vide is that it reduces stress about timing and temperature. Still, it’s helpful to check the core temperature occasionally as you learn. Use a digital thermometer and insert it into the thickest part of the food without removing it from the bag or bath. But don’t check obsessively. It’s not necessary, and once you’re comfortable you’ll rely on it less and less.
FURTHER READING
- 72-Hour Braised Short Ribs
- Four Simple Steps to Sous Vide—Modernist Cuisine at Home, p. 50
- Cooking and Reheating—Modernist Cuisine at Home, p. 60
- Strategies for Cooking Sous Vide—Modernist Cuisine vol. 2:242
- Strategies for Chilling and Reheating—Modernist Cuisine vol. 2:252