Tuesday, December 15, 2009

Efficient cooking, made complicated!

I was at a fundraiser in Eugene last week, and got in a conversation with a local woman (whose name I did not catch) about the most energy efficient way to cook. She told me that the pressure cooker was the most efficient kitchen appliance. The entire conversation was nagging at me for a few days afterward, however, and it wasn't until just the other day that I realized why. The straightforward way of thinking about this issue was actually totally backwards.

First, here are some of the straightforward facts that she was operating with. When we cook, we either burn some fuel (natural gas, charcoal e.g.) or use electricity to heat our food. Electricity can heat food in a couple of ways: most electric heating elements are just a simple resistor (a material that resists electric current), which turns 100% of the electricity it resists into heat with theoretically perfect efficiency. All electric heating elements have the exact same basic efficiency, from your portable space heater to your hairdryer to your electric stove. Electricity can also be used (as in a pressure cooker) to pump hot steam into a contained space, which increases the temperature even more efficiently. This increase in efficiency is similar to the way that a geothermal heat pump heats a house more efficiently than an electric space heater. Burning anything to cook is less efficient, and also releases more carbon gas.

All of this, however, misses some important points about how we use our homes. The assumption is that the heat will be used to heat the food, and then be lost to the universe. After beginning my first winter in a place that actually gets cold, I realize that this is just not true at all. When the oven is running all day, the thermostat controlled home heating doesn't turn on. The point is, in the winter there is no such thing as 'waste heat.' And since my oven heats the house with the same efficiency as the built in heating system (the apartment has electric heat) there is no functional difference between one and the other. In fact, the oven is more efficient in a way, because the heat is being used for two purposes: first to heat the food and second to heat the home.

Back before the power grid and natural gas hookups, every home had one fire that ran more or less non stop and served every function that requires heat in the home. Over that fire, water was boiled and food was cooked. The fire provided heat for the home, light for that room, and a place for the family to gather all winter long. Today, we have a separate appliance for every function. An oven, a pressure cooker, a crock pot, a toaster oven, a fridge, freezer and heater, not to mention all of the various motors that we need (a blender or a mixer, e.g.), and our countless entertainment devices. All of these things consume energy and use it for one and only one purpose. When you start thinking in this way, it becomes obvious that the pressure cooker is not more efficient in the winter, because there is no "waste" heat going in to your home.

So then what do we do in the summer? When it is too hot for that extra heat to be useful, the issue is reversed. Then that waste heat is really wasteful, because it will cause your AC to work extra hard! So if it is really hot, chilling out with a cold dish is ideal. This is also just obvious when you think about it, summertime is when we want to eat salads and sandwiches and (some of us at least) gazpacho. We want cold food because we are hot. In the winter, when it is freezing outside, it is lovely to have baked goods, homemade soup, etc. all of which requires the oven and stove to be burning away all day long. This is a not a coincidence. When you go back to that one fire scenario above, people didn't want the fire burning all day and night when it was ninety degrees out, and they did want it when it was below freezing. In other words, our habits have been developed over centuries, and the recent innovation in technology has thrown us a little out of whack.

I am not a Luddite, I love technology. But sometimes our really advanced and clever solutions (like using electricity to make your house cold) cause us to forget the really simple solutions that we have been using forever (light linen clothes, cold food and drink). And sometimes those simple solutions are extremely satisfying.
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Wednesday, December 2, 2009

The Stock Pot

The other day I made a lentil stew. I was not expecting much out of it, I have made it before and it is usually bland and only moderately satisfying. This time, however, I was shocked to discover that, although I did not do anything interesting with it, it was totally delicious. The kind of delicious that finds you moments later scraping the last bit of stuff from the side of the bowl wondering if you should have seconds, extending the bliss, or savor it tomorrow as leftovers, repeating the moment.

I retraced my steps. What had I done differently this time? I used the same spices in roughly the same proportion, I added tomatoes, but that hardly explained the drastic change in quality. I concluded in the end that there was only one real difference: I had used chicken stock that I made from scratch.

The tradition of making stock is all about efficiency, utility, and reducing waste. Back when meat was extremely expensive (you had to pay a chicken in grain for months and months to get one meal's worth of meat), people felt the need to extract every milligram of protein, mineral, and flavor from their animals. In many cultures, the practice of boiling the bones and remnants of your harvested livestock developed to reduce the waste. Not because they were concerned with waste, mind you, but because the food product of the animal was so valuable that it was crazy to just throw it away.

Although this process was developed to utilize the waste, the result was so delicious that it became an important part of the cuisine of many cultures, and today is ubiquitous in the culinary arts. While dehydrated stock (bullion) and canned stock have been around for as long as the technology of canning and drying, they were originally developed as a convenience for travelers or otherwise encumbered people who could not make their own. Stock prepared from scratch is considered to be superior by most (myself included), and few restaurants will admit to using canned stock these days.

So why is it that most home kitchens have sacrificed flavor for convenience? Canned stock has become so common that most of us have never made stock at home. Also, it is quite time consuming, and many cannot imagine spending 5 hours around the kitchen, even on a Sunday. To make matters worse, those who endeavor to make a first attempt can be permanently put off by a single failure (there is nothing worse than spending 5 hours on food, and ending up with something unsatisfying). However, making stock is not difficult or labor intensive; even though it takes a lot of time it requires almost no attention. Stock keeps in the refrigerator (though it must be taken out and re-boiled every 3 or 4 days) and freezes without loosing any of its flavor, and a good stock will vastly improve the flavor of the most simple dishes. If you, like Courtney and I, are trying to eat less meat, stock adds that meaty flavor to your vegetarian dishes. And finally, if you have never had home made stock, it tastes amazing compared to the can, which was the point of the lentil story at the top of this post.

So, after all that, here is a simple recipe for stock. I will try to cover the common pitfalls that can lead to an unsatisfying result.

Basic Chicken Stock:

Carcass of 2 chickens:

The simplest way to get the chicken material is to keep all of the less appetizing parts of a chicken that you have roasted previously (the back, the bones, the giblets, and wings are good for stock). You can freeze the remains after roasting and make the stock whenever you want. Alternatively, you can try to find a 'stewing hen' (chickens which lay eggs for many years don't yield good meat). There are other ways (buying a huge pack of chicken wings) to get good stock material, but they mostly defeat the purpose of utilizing waste.

1 or 2 Carrots, roughly chopped
1 Onion, quartered
2 Celery stalks, roughly chopped
1 Bay leaf
1 or 2 Other fresh Herbs (optional, don't go crazy)
Water to cover, at least 1 quart

The key to stock making is simplicity. Remember, this is not supposed to be a finished product, it is an ingredient. I never add salt or spices to stock at all. I typically use thyme in addition to the bay, and not one other thing. Simplicity yields versatility, and that is the key for a tasty stock that can be used as a base for any meal. As Chef Shaun Hill says in The Cook's Book (my favorite kitchen reference), the stock pot is not a "swill bin," for tossing in any scraps and junk. That is what the compost bin is for.

First, roast the chicken parts in the oven at 400 F to render away all fat and brown all over. Do not allow any part to burn, but deep browning adds a rich flavor and generates the color of the finished stock. When the browning is done, move all the chicken to the stockpot, drain off all fat and deglaze the roasting pan with water. Pour the deglazing water into the stock pot.

Put all the remaining ingredients into the stock pot and add enough water to cover. Bring to a boil. Simmer until the bones are disintegrating, several hours. Check the stock regularly, skimming off any foam or impurities, and adding more water if the level drops below the other ingredients. It is important that the solids remain submerged for maximum flavor extraction, but more water than just enough is not necessary, and will only dilute the stock.

When the stock is ready, strain the liquid into another container with a ladle. the solid ingredients may contain some more liquid, so allow them sit for few minutes or press them to extract the last bit of stock.

Allow the stock to cool to room temperature before storing in the fridge or freezing. Stock will most likely jelly when cooled. If stored in fridge, take out and bring to a boil every three or four days to preserve. Keeps in freezer for up to a year. This stock will be fairly concentrated, and can be mixed half and half with water when making soup or stew. Add a little less water if making risotto. Do not dilute if making sauce.

Chicken Stock on Foodista