Q: What’s Sous Vide?
A: The term sous vide (pronounced like “soo veed”) cooking comes from the French words for “under vacuum.”
Cooking with heat means the application of heat to food, over a certain amount of time. You can apply high heat for a short time, or low heat for a longer time. However that relationship breaks down as the temperature difference increases. For instance, tossing a steak into an erupting volcano for 1 second is not going to give you the same results as “cooking” a steak at room temperature on a pan for 1 year, even if the amount of energy is equal. Furthermore, there are certain temperatures where the constituents of food break down a lot faster–just like how water abruptly changes from solid to liquid at 0 degrees Celsius, egg whites have a temperature threshold that needs to be met in order for the egg whites to whiten and coagulate (about 145-150 degrees Fahrenheit depending on the exact chicken egg in question).
So the basic idea behind sous vide is to submerge a sealed (not necessarily vacuum sealed) packet of food into a water bath at an “ideal” temperature so that the food cannot overcook even if you leave it in the bath for a little longer (or sometimes a lot longer) than necessary. For instance, if you want a medium rare steak, you can seal the steak in plastic and dunk it into 135-degree F water for long enough that the coldest part of the steak reaches 135 degrees Fahrenheit. If you leave the steak in longer than that, by 10 minutes for example, the steak will slowly break down further, but nothing like if you overcooked a steak by 10 minutes on the stovetop. A 10-minutes overcooked sous vide steak is fine, but a 10-minutes overcooked stovetop-cooked steak would be a charred, black lump.
A steak that spent the last 2 hours in a 135-degree F water bath will taste disgusting, so the next step would be to sear the steak briefly–just long enough to get a brown crust on each side. Then deglaze the pan and serve. You don’t need to rest the meat, because the meat already reached safe internal temperatures a long time ago. Just eat it.
Q: What are the upsides to sous vide cooking?
A: Evenly-cooked food. And there are some exotic recipes that can’t be cooked any other way. Think of it as braising on steroids. It’s mainly good for proteins where you would like the meat to be juicy and tender, yet to also be at a safe internal temperature. Cooking meat on a stovetop pan would tend to overcook the exterior in order to get the internal temperature up, whereas sous vide lets you get the entire steak up to temperature, and then spend a minute to sear the outside on a pan afterwards. If you’re a vegetarian, sous vide can help concentrate flavors in vegetables but is not as useful overall.
Q: What are the downsides to sous vide cooking?
A: If you’re wondering “what’s the catch,” there are a few things to watch out for:
- Pathogens. Warm water is a great way to breed bacteria. Some bacteria and parasites do not die fast enough when cooked at low temperatures.
- Plastic safety. When cooking sous vide, you must encase food in something–typically plastic–in order to prevent juices and flavors from being lost to the surrounding water. So you are in effect, cooking in plastic. Some people do not like the idea of cooking in plastic or silicone, and I don’t blame them. History is full of arrogant people proclaiming things to be “safe,” only to be proven wrong, whether it’s the “unsinkable” Titanic or Thalidomide (a West German drug for morning sickness that produced birth defects). The problem with chemical regulation in the USA is that there is none. People seem to think that the US government makes sure chemicals are safe before being introduced to consumers, but the reality is that chemicals are assumed safe until proven otherwise. The main reason why you don’t have really bad chemicals in most products is because companies are afraid of lawsuits, not because the FDA is looking out for you. That said:
- Ziploc bags are made out of relatively safe plastic, polyethylene, but polyethylene can break down when exposed to ultraviolet light or some chemicals, so store them in a safe place. Also, do not heat Ziploc bags above 180 degrees F (about 82 C), as the bags will soften and melt as you approach 200F. And avoid anything that is not pure polyethylene, such as colored bags.
- Food-grade, FDA-approved silicone is probably safe but given that it can stain and change texture over time (e.g., with enough dishwasher cycles), I wouldn’t cook in it for a long time, if I could help it. Silicone also does not deform as much, so you get poorer seals. Silicone bags also cost a lot. Frankly I see no point in using silicone bags over Ziploc bags.
- Glass, like glass Mason jars, are probably safest due to how chemically non-reactive glass is, but it also takes longer to cook and will trap more air along with food.
- Cost of bags and bag sealers. The common types of sealer include:
- Chamber Vacuums. Each seal costs you 7-10 cents per sealing; the cheapest one in production (the VacMaster VP115 Chamber Vacuum Sealer) still cost over $750, and there are reports that parts malfunction after a while, such as cracks in the plastic (not metal!) tops. You place food in-between layers of plastic. This all goes into a chamber, with the trailing, unsealed edges of the plastic poking out of the chamber. At a predetermined point, like achieving a strong enough vacuum, the chamber vacuum then thermally seals the plastic.
- Something like a FoodSaver V2244 Vacuum Sealing System will suck out air of special plastic bag material but not create a vacuum, and that’s good enough for most purposes. The problem is that each sealing (pouch or portion of a roll) will cost you as much as 50 cents each, though buying in bulk can drive the costs down. Furthermore, you can’t really use liquidy foods with suction sealers without first freezing the liquids. Otherwise the suction mechanism will suck things like raw chicken juice into the machine. Foodsaver also makes a FoodSaver Regular and Wide-Mouth Jar Sealer to adapt its machines to regular or wide-mouth Mason jars.
- Manual Hand Vacuums. The idea is to take a plastic bag and add a one-way valve to it. Then pump the air out. The Ziploc Vacuum Starter Kit, 3-Quart Bags, 1-Pump may be a name brand, but it’s enormously expensive on a per-bag basis. Not good for liquidy foods as liquids can clog up the pump.
- Powered Hand Vacuums. Like a manual hand vacuum but with a motor. Not good for liquidy foods as liquids can clog up the pump. I almost bought a Waring Pro PVS1000 Pistol Vac Professional Vacuum Sealer System, and Waring also produces a variant with more pre-bundled bags, but I’m not sure I’d recommend it.
- First, the battery is not user-replaceable and despite a 5-year warranty, the battery will wear out eventually, which adds to cost. In order to keep the battery alive, the unit must be plugged in at all times; if fully drained the smart charger will not recognize the unit unless you hotwire it per the Amazon reviews that mention this problem.
- Second, the bags are only semi-reusable; after enough uses you need to replace them.
- Third, Waring would not say what the plastic bag material is in their marketing materials. I asked and a customer service representative told me: “Bags are made of Polyethylene, the same as the bag material seen with standard commercial vacuum sealers used by professional chefs cooking sous vide. They are FDA approved materials. No BPA no phthalates.” Great, but I’d feel better if they were confident enough in their material to say so on the box.
- ThriftyVac was a Kickstarter project that has long since expired. If you want to buy the system now, it will run you around $25-30 for the starter set. In their own words, “ThriftyVac® works by placing your food bag inside a larger plastic bag, and pumping out the air from the larger bag, thereby vacuum packing both bags. This product works best with its high-quality, low-cost TV2 Vacuum Bags. It does not work with sliding zipper bags that are not designed to hold a vacuum.” The larger bag has a one-way valve and is reusable. The system is not good for liquidy foods if the liquid makes it to the valve and gets sucked into the hand pump. In theory a ThriftyVac is affordable because you can use relatively cheap Ziploc or other plastic bags to hold food, and the more expensive outer bags (with the built-in valves) don’t cost that much either. They even sell Mason jar lids with valves in them, so you can use the ThriftyVac hand pump to vacuum most of the air out. Whether or not ThriftyVac actually works better than simply dunking-and-sealing Ziploc bags is a matter of dispute, however, and even the designer recommends that you use a bit of olive oil to help seal the smaller bag.
- Ziploc Freezer Bags. This is the cheapest way to sous vide, but it won’t work for liquidy foods, and it doesn’t give you a vacuum seal, either, which is required for some of the more esoteric sous vide recipes. Quart-size is enough for small cuts of meat and fish; use gallon-size for larger cuts or multiple cuts. The idea is to place food into the Ziploc bag and to slowly lower the bag into water, allowing the water to squeeze out the air. Once most of the bag is lowered, you can seal the top. If you do this carefully, you can get a “good enough” result that won’t be much worse than a ThriftyVac or FoodSaver result. You could use ordinary Ziploc bags as well, but the Freezer bags are built thicker and may be better for longer or hotter cooking.
- Silicone bags. The Lekue 1-Liter Fresh Bag seems to be the only game in town right now for these types of bags. Think of these as reusable, dishwasher-safe Ziploc Freezer Bags that don’t work nearly as well. The silicone will not deform as much when using the water displacement method. I think people buy these bags because they do not like the idea of cooking food in plastic.
- Regular or wide-mouth Mason jars. Perhaps the safest way to sous vide, if you do not want to cook food in plastic or silicone. The ThriftyVac system (see above) would likely be your cheapest option unless you already had a vacuum system from another manufacturer and can buy an adapter. For instance, Foodsaver makes a FoodSaver Regular and Wide-Mouth Jar Sealer to adapt its machines to work with Mason jars.
- Cost of heating and circulation equipment. Your choices are enclosed water baths and thermal immersion circulators.
- Enclosed water baths like the Sous Vide Supreme Water Ovens (available in large (11.2 liter) and small (8.7 liter) sizes) are basically insulated containers with heating elements. Think of them as giant slow cookers with precise thermometers. The advantage of enclose water baths include having a fitted lid that cuts down on evaporation and thus improves efficiency, since the heating elements do not have to turn on as often. The insulated sidewalls also help efficiency. Downsides: these units take up a lot of space, are not particularly easy to fill or to drain, do not give you the flexibility to use different-sized pots, and cheaper units do not have any fans to circulate water, so you can wind up with hotspots. Also, if any part of the unit breaks, you need to send it back for servicing if it’s still under warranty.
- Thermal immersion circulators like the Anova Culinary Precision Cooker/Immersion Circulator (I review it here) are basically heating sticks with a fan and thermometer attached, and with a clamp to hold the stick upright against the side of a pot. The sticks are about the size of a 2-liter bottle, but much skinnier (only a few inches in diameter). The heating element keeps water at the temperature you want, the fan circulates water to ensure that the water temperature is even throughout the pot, and the thermometer tells the heater to heat up to but not beyond the target temperature.
- Cost of cover. If you use a thermal immersion circulator, you will not be able to use the cover that came with your stockpot. You have a few choices such as buying a piece of plastic and cutting a hole in it, wrapping plastic wrap around the top, or simply living with the evaporation and waste heat and higher electric bill that results from having an uncovered pot of water around. By far the most energy-efficient cover, though, is air, such as the air inside plastic balls like these Sous Vide Bros. balls or Grant Instruments SV-PS20 Sous Vide Polypropylene Spheres (Pack of 200). You might wonder why you wouldn’t use ping pong (table tennis) balls instead. That’s because ping pong balls are too big, so they leave larger gaps for water to evaporate. Also, ping pong balls may not be rugged enough to withstand repeated use, especially in hot water, and they probably would not be dishwasher safe.
- Water Usage. If you are in a drought stricken area, sous vide can use a lot more water than other cooking methods. On the other hand, you can reuse the water by watering plants with it.
Q: From the list above, what’s the cheapest way to start sous vide cooking?
A: Assuming you already have a stock pot, I would recommend getting an Anova Culinary Precision Cooker/Immersion Circulator (I review it here). It’s the cheapest thermal immersion circulator out there, it doesn’t take up much space when unused, and it’s pretty good. Next, I would get quart-size or gallon-size Ziploc Freezer bags. A quart-size bag is enough for a small steak, but if you want a bigger margin of error or to cook multiple steaks, get the gallon size. If you want to cut down on waste heat in your kitchen or energy bills, I would suggest making a makeshift cover out of plastic wrap as well. And that’s it! That’s all you really need.
Q: Does it matter what kind of stock pot I use?
A: Not really. It does take a little longer to heat up a pot full of water in cast iron as opposed to, say, stainless clad, but not so much longer that I would write off the cast iron. I also did an experiment where I tested heat retention ability of stainless clad, disc-base, and enameled cast iron, and the differences are not big enough to worry about unless you are planning to do extremely long sous vide cooking. Try to have a decent cover, though, even if you have to make one out of plastic wrap.
Q: Is sous vide worth it? (Is sous vide worth the time? Is sous vide worth the effort?)
A: Ann works in the food industry, and her opinion of sous vide is that while it can indeed make great-tasting dishes, it should be left to professionals or else to home chefs who are particularly conscientious, knowledgeable, and have first-rate equipment. You need all three:
- The conscientious part comes in where you don’t try to short-cut the process, handle food safely to avoid cross-contamination or other problem, etc. For instance, you should preheat the water for sous vide, rather than relying on your sous vide heater to do all the work. That way your food spends more time in hot water and less time in lower temperatures that encourage bacteria to multiply.
- The knowledge part is tricky. For instance, most popular sous vide recipe sites say you should cook salmon at 122 to 125 F without saying a single word about parasites that can survive those temperatures. For instance, 75% of all wild-caught Pacific sockeye salmon has the parasitic worm that causes anisakiasis.1 Stuff like that feeds into the perception that non-professional sous vide chefs either don’t know or don’t care about the risks.
- Equipment must work. Sous vide recipes often dance at the edge of safety, so you better hope that the thermometer you use for sous vide never breaks or gets significantly miscalibrated. Double-check your thermometers once in a while to make sure they are calibrated, e.g., by plunging them in ice water to verify a zero degrees C reading. It wouldn’t hurt to give your food an extra 0.5 to 1 degree F boost, either, to give yourself a slightly larger margin for error.
I can understand Ann’s opinion. If you can often cook something conventionally and get nearly-as-good results as sous vide, with less risk and sometimes less hassle, then why bother with sous vide?
As for my opinion, I just got a pair of Anova Precision immersion circulators for thermal tests, not necessarily for sous vide. But I tested some sous vide steaks anyway. After cooking some ribeye steaks and salmon, I have to say that sous vide is very good for two things: consistency and time flexibility. This makes sous vide very good for cooking for guests, because a) there is less stress over messing up a steak, and b) if guests show up late or at different times, that’s fine–steaks won’t overcook if you leave them in the water bath for an extra hour or two. And if your guest is more than a few hours late, then it’s hardly your fault. Furthermore, we managed to turn $25 worth of ingredients and electricity into $100 worth of fancy-restaurant-quality steak. So if you like things like steak, seafood, and eggs, a sous vide immersion circulator can pay for itself very quickly.