Tuesday, November 15, 2011

Tempering

For years I was perplexed as to how professional cooks got meat to look the way it did when it came out on the plate. Whether it was the prototypical X marks on steaks and chicken or perfectly seared pieces of tuna, making food look they way I wanted it to always eluded me.

Just to clarify, I want to show some examples of what I think some food should look like and what it should not look like.

The Good:


The Bad:


Lets make a few observations:
  • The color on the good pieces of meat are uniformly distributed, making a neater looking appearance.
  • We have grill marks on the good pieces of meat. The X-ing pattern adds flair but the most important part is the clearly visible grill marks. The grill marks are signs of caramelization and oxidation which leads to sweet and smokey flavors, respectively.
  • The colors of the meat are dynamic. By dynamic, I mean that the color of the meat quickly changes from a light tone to a dark tone when moving from the non-grill mark areas, to the grill-marked area.
For the inside of steak:
                      Good:                                                                   Bad:


What do we see here?
  • The good steak has a dark outer color and the bad one only has a dark caramel color on the outside. Also notice that the good steak is more rare and therefore cooked less, but also appears more cooked on the outside. No matter if its rare or well done, you can achieve this rich coloring to all your meats. In my opinion this is the most important part of making a good steak. We want some of that burnt carbon flavor on the outside to work with the minerality of the steak.
  • The color of the good steak is more dynamic than the bad one. In this example, dynamic means that the colors clearly distinguish the well cooked outside from the rare part inside.
    When I cook steak, I always try and achieve the seared tuna steak look:
    This is the perfect example of dynamic colors. The pink meat is nestled in a jacket of gray, and the outside is dark-colored. Examples of tempering are most obvious when using meat but it actually works and improves any refrigerated food.Vegetables, fruits and nearly everything you apply heat to will taste and look better.

    Tempering:

    Tempering is a cooking technique where we bring an ingredient such as steak to a desired temperature before we cook it. And yes, it is easy as it sounds. Bring your food to the right temperature and you will see a drastic improvement in the looks of your foods. That's it. With that said people tend to not do this for three reasons:
    • Ignorance: they just never had anyone tell them to temper their meat.
    • "Food safety": Since tempering meat involves the meat to enter the "danger zone" people think its unsafe to let food sit on the table for some time before they cook it. This is untrue as long as you don't leave the meat out for too long. Most cuts of meat can be left out on the counter for an hour and be ready to go. This is two hours less than the maximum time that meat can be in the danger zone.
    • Time: It takes 30 minutes to an hour to temper most foods. People seem to get into the routine of taking their food out of the fridge, cooking it and eating all in one fleeting motion. Tempering requires you to take the food out, wait, and then cook and eat.
    If you don't have a problem with the last two points you're good to go on tempering. All you need to do is let your food sit at room temperature until it reaches the appropriate temperature. That's it. No equipment, no nothing. That being said, there are some different times for different foods.

    Tempering guide:
    Put your food on a clean surface at room temperature:

    • Poultry, beef, pork, lamb, fish, large seafood etc.
      •  This is the largest varying time scale because meat cuts come in so many sizes. The general rule goes like this:
        • Cuts between 0-1 lbs: 30 minutes
        • Cuts between 1-3 lbs: 1 hour
        • Cuts larger than 3 lbs : 1.5 to 2.5 hours
    • Produce
      • This is the easiest group of foods to temper. I use a method I called the onion rule:
        • For every large onion sized piece of produce, I leave it to sit for 10 minutes. So, if we have a cabbage that's about the size of 4 onions, I leave it out for about 30 to 40 minutes.
    • Cheese
      • Most cheese should be served at room temperature, though this is not true of all cheeses. If you have any doubts, just do a quick google search. Whats more important is to make sure the cheese is wrapped in some way so that the cheese will not dry out on the outside while it sits on the counter.
    • Doughs
      • A lot of yeast doughs need to be at room temperature for two hours or so before being cooked. Most others will benefit with an hour or so on the counter.
    •  Other foods
      • Many other foods will benefit from some time at room temperature. Just use your best judgement and make sure that the food wont spoil. Nothing will spoil if you let it come to room temperature and then proceed to cook it immediately.
    Clearly you might run into foods that are very large and impractical to temper using this guide. If that is the case, or you just don't have all the time needed to temper completely, you can always partially temper. This applies to all the foods listed here.

    Why we temper food:
    The theory behind tempering has to do with chemistry and biology. When we apply heat to a food three basic reactions happen; caramelization/Maillard reactions, redoxing, and denaturing. Depending on the food you cook, the heating element you use, the amount of heat you apply, and several other variables each of these three processes will express themselves differently. The processes themselves never change though, so it is good to be aware of how they work and what to look for:

     Caramelization and Millard reactions:
    If you read my post on Umbrian Lasagna you might remember that I mentioned how important it was to brown the vegetables when making the sauce. What I was really telling you to do was to "caramelize" the vegetables. Caramelization occurs when the sugars on the outside your food reach a certain temperature (usually 160F) and results in a light to dark brown hue on your food. Caramelization occurs when we cook vegetables, fruits and most other foods not rich in protein. A Maillard reaction is a cousin of the caramelization process. A Malliard reaction occurs in the presence of sugar, proteins (amino acids), and heat. This reaction has no specific temperature that it happens at since the ratio of proteins to sugars is very important in determining this, and can vary greatly. The more important thing to take away is that this is the reaction you see when you cook meat, breads and all sorts of protein rich foods. (This was important in giving us the right color on the outside of the steaks/chicken.)

    In my opinion, if you're cooking a food in an environment that caramelization can occur then it should occur. High heat environments such as saute pans, grills, hot ovens ( greater than 375F), and deep fryers should all caramelize your food to some scale. Its also important not to over-caramelize your food, or you'll have a redox reaction on your hands. (We'll get to that next.)

    So how does tempering help us caramelize food? The idea is rather simple and will be the reason for all of the other reactions: all things held constant, we will apply less heat to the food when we cook it. When you throw chopped onions fresh from the fridge into a hot pan, the first thing that happens isn't cooking. Rather, the cold onions bring the temperature of the pan down/the pan has to warm up the onions first. (This alone increases the cooking time as both the pan and the onion have to come back to temperature.) Then, once that happens the onions will begin to cook. Caramelization will only happen at high temperatures, which might happen less or not at all if either the pan is not hot enough or, the onions never get hot enough before they're fully cooked. So to avoid cooling the pan, increasing cooking time, and increase caramelization, we temper the onions first and bring them to room temperature.

    Redoxing:
    I like to think of redoxing as your best friend and worst enemy in the kitchen and on the grill. The right amount of it will make your food look professional and taste much better. Too much of it and you will have burnt food. The grill marks discussed before are an example of redoxing. Since part of the meat was in contact with the grill, receiving more heat than other parts, that part burned just a little. This gives us the dark black lines on the meat. This action happens after caramelization when the temperature is a lot higher than 160F, resulting in a smokey flavor left behind by carbon molecules. So in essence, redox reactions are a form of burning the food in small amounts.

    The reason why we use tempering to enhance redoxing is the same idea behind caramelization. Using less heat, we can cook the food at a higher temperature for a shorter time, resulting in less overall heat applied to the food for better looking, better tasting food.

    **Note:
    Never try to induce redoxing (burning) when grilling. You'll overcook or completely burn your food. Just make sure to temper the food and that your grill is completely cleaned and preheated. If all these things are done correctly you should be fine. I get different results each time myself.

    Denaturing:
    Whats the difference between rare and well done? Denaturing. The denaturing of biological compounds such as proteins and enzymes are extremely important to consider when you cook. When we add heat to meat we can see the color change. What you're watching is denaturing before your eyes. You see, proteins are complex bundles of amino acids and when you apply heat to them they unwrap themselves and take on a bunch of new properties. (Such as a new color.) See the example above where the steak is grayish around the outside and deep red on the inside.

    To achieve a "well-denatured" food we always temper. Tempering protein foods like meat will result in perfectly cooked food because of the same principles explained before. Tempering means less heat applied overall, which results in a more "natural" taste and texture from our proteins. By natural, I mean moist, tender and good looking food. Overly denatured foods always come off dry and tough since all the biological chemicals have basically been destroyed.

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