Torch Tastes

MCFebruary 18, 2011

In response to my recent post on “doneness,” reader Rusty Shackleford posted the following question: “When using my blow torch, sometimes I notice unpleasant propane tastes. Anything you can tell me about general blow torch cooking?”
Blowtorch Searing Short-Rib
This brought to mind a similar question that I was recently asked about the use of other flammable gases in cooking. As is often the case at The Cooking Lab, one question leads to another and before I knew it, my short answer had grown beyond the scope of the original question. We cover the topic more extensively in the book, but here is a brief description of how the use of a blow torch and the type of gas therein can affect the flavor.

Natural gas (methane) is a common fuel for ranges and stovetops, but most torches used for cooking are fueled by propane or butane. Fuels like oxyacetylene and MAPP gas, however, typically burn hotter and thus can impart a larger amount of heat to the food for a faster sear.

The type of gas that you choose isn’t as important as the completeness of its combustion. Propane, butane, MAPP, and acetylene are all great so long as you adjust the flame of the torch so that it is a fully oxidizing flame. This is a flame that is produced with an excess of oxygen, either from the surrounding air or supplemented with compressed oxygen. You can tell that you have an oxidizing flame when the torch is burning dark blue, is relatively short in length, and hisses and roars. Frequently, people have too large of a flame that is burning yellow at the tip. This is a reducing flame, also referred to as a carburizing flame because there are uncombusted hydrocarbons from the fuel in the flame that will end up in the food, imparting an unpleasant taste. In my experience, butane torches are especially prone to this, but it can happen with any torch that hasn’t been properly adjusted before aiming it at the food.

Too often, people aim the blow torch at the food before they have it appropriately adjusted. Not only do they often end up torching the food with a dirty flame, but there is also some raw fuel being blown onto the food before it ignites. Like an old, carbureted car (and for the same reason), it is best to light the torch and adjust the fuel-to-oxidizer ratio before getting underway.

Long story short, always light your torch facing away from the food. Then adjust the torch to produce a short, hissing dark blue flame and you won’t have a problem.

6 Responses to “Torch Tastes”

  1. Hello!

    It seems to me that there is also more to torching food that the oxidizing flame. One aspect, which I haven’t seen mentioned in MC or MCAH -but I may be mistaken- is the coating of the surface. I recently purchased a MAPP torch, which on the same night did extremely well on the instant swiss meringue, and gave my barely-medium-rare salmon the taste of burnt hair. And videos I have seen on the net of chefs torching nigirizushi, for instance, give me the impression that there searing was not much different from mine.

    Hence my questions:
    -does searing with a blowtorch always work as well as hot-as-hell-pan-searing ?
    -should we coat some meats/fishes (with oil ? yakitori sauce ?) before torchearing them ?
    -light touches with a back-and-forth movement to raise the temperature slowly but evenly in several passes, or constant medium speed to reach the desires level of crustiness in one pass ?



  2. Hello again,

    Maybe I am the only one having this problem, but if it’s only because I am not clear, i’ll try to exemplify it a little:

    Let’s imagine a piece of pork skin, with hair on it. It seems to me that, no matter how hot the torch, how skilled you are at searing, it WILL taste off because of the burnt hair.

    Now although I don’t see why people would want to sear hairy pork skin, it also looks like some surfaces may have the equivalent at the microscopic level, such as cellular membranes that will produce off tastes when heated with a flame. These tastes would not be of fuel, obviously…

    That’s the only explanation I see to the difference between meringue and salmon which I mentioned above. So if anyone had either an explanation or a way of preparing the surface of the food to avoid these problems, I’d be delighted.

    Thanks and sorry for insisting, I hope this will be of interest to others.



  3. Michbill

    You might want to take a look at Dave Arnold’s Cooking Issues blog. They are beta testing an adapter for torches (like a metal gauze that gets super hot), and they believe it greatly diminishes torch taste. They are going to make it available as a kickstart project, and he has a nice discussion of torch taste on the blog.

  4. Hi, I was looking into torches and was all ready to buy the benzomatic MAPP gas torch when my wife read the warning label saying it contained brass parts and may contain lead which may in turn lead to cancer. Is the benzomatic safe? Has the finished food ever been tested for lead? I have a butane torch now, and it’s all aluminum construction, but it takes forever and I really want to get something that will brown it faster. Any help would be appreciated.

  5. Sam Diaz

    Blow torching food is for the insane. You have to study the harmful effects of burning anything (fuels, paper, candles, etc) to come to light about how insane is to apply a gas torch to sear your food. You may as well eat poison or cancer causing substances. Most humans are very ignorant about the thousands of toxic chemicals pruduced from the combustion of fosil fuels, or from any combustion. Please, for life’s sake, dont burn anything.
    For more information you may want to visit the US EPA web page on air quality and air toxics, or do research on the wealth of empirical available on this important subject.