The final step in most sous vide recipes is to "finish" off the surface of the protein. This might include making chicken or fish skin crispy or creating the Maillard reaction on a piece of meat to get that dark, crunchy, flavorful crust. This usually entails searing, using one of several methods covered in this guide to searing sous vide foods.
This article will focus on the use of a torch to provide the finishing sear on sous vide dishes.
I would like to cover a few sous vide torching topics before presenting the various torch options and my recommendations. But if you're in a hurry you can go directly to my Sous Vide Torch Recommendation.
The torches covered in this article are not the small kitchen or pastry torches used for tasks such as caramelizing sugars, browning meringues and melting cheese. They simply do not put out enough heat to sear a typical sous vide dish in a reasonable amount of time. Even the most powerful of these reach temperatures of only 2,500°F.
The best torches for searing sous vide are ones designed for "industrial" uses such as soldering copper pipes, brazing and hardening steel, as well as light welding. These can reach temperatures greater than 3,500°F, which will provide enough heat to sear a typical sous vide dish in about 2 to 3 minutes.
The phenomenon of "torch taste" will invariably be brought up whenever the torch method of sous vide finishing is discussed. Torch taste is the unpleasant "gaseous" or "fuel" flavor that is often associated with dishes that have been finished with a torch. Initially the presence of torch taste was attributed to the chemicals contained in the fuel itself. There was often discussion as to which of the more popular fuels: propane, butane, or MAPP caused the greatest amount of torch taste when used.
Recently, however, some tests run at UC Davis indicated that the primary cause of torch taste was the creation of new, unpleasant, chemical compounds on the food when the heat is too high. These results would indicate that controlling the temperature at which the sear is performed is the most important factor in reducing the presence of torch taste.
There are numerous types of gases that are used in torches and each has its unique set of characteristics. Here are several of the main types of gas used in sous vide torching.
Historically MAPP was considered the best gas to use in a sous vide torch because it burned hotter and thus seared faster, than the other gases available. It was sold by DOW at a premium price because of this advantage. However, MAPP is no longer available and has been replaced by MAP-Pro which is actually just an enhanced version of propane.
This is the successor to MAPP but is actually just a variant of propane which burns approximately 150-200°F hotter. It is unlikely that you will notice much of an impact when searing sous vide food because of this relatively small difference in temperature. And since MAP-Pro still carries a price premium, most people prefer to go with straight propane.
Propane is the most popular of the gas types because of its low price and adequate heat generation capability.
Butane burns cooler than the other gases and is often used in the smaller "kitchen" or "cooking" torches.
The type of gas used is not nearly as important as the technique used to perform the sear. The most important thing is to be sure that the flame produced by the torch is a fully oxidizing flame. In this type of flame the gas is being completely combusted and can be identified by the dark blue, relatively short, flame that hisses and roars.
If the flame is large, with a yellow tip, it is referred to as a reducing flame. In this type of flame there are unburned hydrocarbons from the fuel that will end up in the food giving it an unpleasant flavor.
So for optimal searing results be sure to not have the torch pointed at the food until it has been lit and adjusted to achieve the short, hissing, blue flame. Then aim the torch at the food keeping it moving so that the food sears evenly but does not burn.
In researching sous vide torches I found the majority of the popular ones were manufactured by Bernzomatic. This company has been designing and manufacturing products in the United States for more than a century. Their torches are known for their reliability and are all very highly rated by real users on Amazon.
Bernzomatic has two torches that would work for searing sous vide food. For a detailed comparison between these torches, here is another article. I will provide details on the two most popular models:
The TS4000 has an instant on/off trigger which increases fuel savings and convenience. This is a real improvement over those torches that you need to turn the gas on and then use some type of sparking device or match to ignite. You simply pull the trigger and you have flame; let go of the trigger and it is off. It also has a lock button which keeps the torch lit without needing to keep the trigger pressed. This is a really handy feature when it may take several minutes to sear a good size steak.
The TS4000 torch has an efficient swirl flame which provides high heat output and is pressure regulated to burn in all directions. The torch can use both Map-Pro and propane.
It has a stainless steel burn tube, a replaceable brass burn tip, and cast aluminum construction which provides added durability.
The Bernzomatic TS4000 Trigger Start Torch is available on Amazon for around $44.00 and at Home Depot for about $35.00. The torch is available at both retailers included in a "kit" which also includes a 14.1 oz. Map-Pro-filled cylinder.
The TS8000 shares all of the useful features of the TS4000 mentioned above. However, the advantage of the TS8000 is that it has a larger high-intensity flame for maximum heat output. Bernzomatic states that it provides a 30% faster soldering time. I suspect you would see a similar improvement in searing time as well.
The TS8000 also has an adjustable flame control knob which allows you to adjust the size and intensity of the flame making this torch useful in more types of applications.
The TS8000 High Intensity Trigger Start Torch is available at Amazon for around $40.00 and at Home Depot for about $40.00. The torch is available at both retailers included in a "kit" which also includes a 14.1 oz. Map-Pro-filled cylinder.
For completeness I have included a torch which uses butane gas. This torch operates a little bit differently than the Bernzomatic ones. To ignite this one you first need to turn on the gas using the grey knob at the back end of the device. You then pull the trigger to ignite the flame. When you release the trigger the flame continues to burn until you turn the gas off with the grey knob. Clearly this is not as convenient or safe as the instant on/off trigger on the Bernzomatics.
In addition to the gray knob which controls the amount of fuel being used by the torch there is also a gray ring that adjusts the amount of air being used for combustion. It can control the output from a very small and soft glow to a billowing flame. By adjusting the two knobs you can modify the shape and intensity of the flame.
The fuel comes in a cassette gas cylinder that looks similar to an aerosol can. The Iwatani unit attaches to the cylinder via a quarter-turn connector.
Although the Iwatani CB-TC-PRO is not as powerful as the two Bernzomatic units mentioned above, it is head and shoulders above the typical "kitchen" or "cooking" units. It may also be more readily available in certain parts of the world than the Bernzomatic torches.
No article on sous vide torches would be complete without covering the ultimate torch accessory - the Searzall. Connect this unique accessory to your torch and you will hold in your hand a supercharged searing machine.
The Searzall was developed by David Arnold at the Booker and Dax Lab and funded by a successful Kickstarter campaign. The goal of the design was to improve the searing capability of the torch while at the same time eliminating some of the disadvantages such as torch taste.
As the Kickstarter article explains, the Searzall converts the torch's single extremely hot and focused flame into a more useful source of infrared, radiant heat, which is much better for cooking. It essentially turns the torch into a hand-held-mini broiler.
The Searzall is now available on Amazon for $75. It has been quite popular and is rated very highly by those who have used it.
This is actually a two-part torch recommendation. First, I believe the Bernzomatic TS8000 is the best torch for searing sous vide dishes. It is relatively easy to use and provides more heat than the other options which will allow you to sear dishes quicker.
Another reason for selecting the TS8000 torch is because it is the one recommended to be used with the Searzall. If you are a serious sous vider, who prefers to finish their sous vide dishes using a torch, it is likely that you will want to try out the Searzall at some point in the future.
You can begin immediately using the Bernzomatic TS8000 torch to get a satisfactory sear on your sous vide dishes. Then at a later date your can pick up the Searzall Torch Attachment, connect it to your TS8000, and raise your game to the next level.