Note : After reading the article, I realized that most of the tips are for enhancing taste and color of the stock. Nevertheless, some chefs have good tips on the process itself.
STOCK TIPS
Chefs offer their do's and don'ts for making this essential base
Source : http://www.sfgate.com/cgi-bin/article.cgi?f=/c/a/2007/10/31/FD0JSAGEJ.DTL
Janet Fletcher, Chronicle Staff Writer
Wednesday, October 31, 2007
If you want to know how to make stock, ask a chef. Just don't ask two chefs.
The more experts you query, the more conflicting advice you you'll get for making this fundamental ingredient of French cooking. But with the season for soups and braises ahead, it seemed like a good time to gather some tips - even contradictory ones - for making this flavor-packed essence.
A freezer full of clear, concentrated stock - whether from chicken, fish or vegetables - gives a home cook a running start on a good meal. The homemade product not only routs canned stock in a flavor match, but it's usually cheaper, too.
Bay Area chefs may disagree on the minutiae of stock methodology, but they concur on the core message: Garbage in, garbage out.
"Stock is not your compost bin," says Annie Somerville, chef of Greens in San Francisco. The image of the frugal, old-school French chef who hoards every potato peel, carrot scraping and onion skin does not correspond to how several meticulous Bay Area chefs make stock today. They start with pristine fresh vegetables, skins removed. Some use filtered water and costly Niman Ranch meat. A stock is only as good as what you put into it, they believe.
Listening to local chefs, another lesson emerges. Good stock doesn't develop from concentrating a large volume of liquid but from using as little water as necessary to draw out the goodness. Many chefs add barely enough to cover the solids; at least one chef - Amaryll Schwertner of Boulettes Larder in San Francisco, who sells her chicken stock for $13 a quart - cooks her stock with parchment paper on top, slowing water loss. No wonder the conventional stockpot is taller than it is wide. Slow extraction, not evaporation, is the key to flavor.
Beyond those two broadly shared views, chefs' opinions on proper technique range widely, so home cooks may choose to merge their guidelines into a hybrid technique. Embrace the methods that make sense to you and that are practical in your kitchen; reject the ones that seem too finicky or extreme. Every detail makes a difference, says the fastidious Schwertner. It's just too bad that chefs don't agree on them.
Consider chicken stock, the cornerstone of the Western kitchen. (Asian cooks have their own stocks, of course, such as Japanese dashi, but the classic European stocks are under the microscope here.) Cooking-school students are taught to use carcasses - what's left after removing wings, legs, thighs and boneless chicken breasts - and to supplement with necks and backs and perhaps a few wings for more flavor. That's the basis of the chicken stock at Coco500, the San Francisco bistro run by French-trained Loretta Keller.
By contrast, in the Zuni Cafe kitchen, cooks remove only the chicken breasts; the rest goes in the stockpot. And Schwertner makes her extravagant stock with the entire bird.
"If you just use the bony parts," says Schwertner, "somebody has hacked those up in a way that exposes a lot of blood and bits of bone. It's creates a murky color and murky flavors, so we leave the whole carcass intact." Zuni Cafe chef Judy Rodgers also emphasizes the importance of not cracking the bones - by hacking the carcasses to fit them into your stockpot, for example - to avoid extracting undesirable flavors.
By comparison, an Asian view: The late Barbara Tropp, author of "The Modern Art of Chinese Cooking" (William Morrow, 1996), recommended chopping the chicken bones with a cleaver "to expose the marrow and enrich the stock."
Whatever chicken parts you use, they must be well rinsed to dislodge any bloody bits. Some chefs remove visible fat; Rodgers leaves it, convinced it adds flavor.
The chicken goes into the pot with cold water to cover - but to cover by how much? In her acclaimed "Zuni Cafe Cookbook" (W. W. Norton, 2002) Rodgers suggests 4 quarts water to one 51/2-pound chicken and tells readers not to worry if the bird isn't submerged. (It won't be.) Cut off the wings or legs so the carcass sits lower in the pot, she suggests, but don't add more water.
Schwertner is more generous with her (filtered) water. "Don't think about ratios," she says. "It depends on the scale of the pot. You want to make sure your bones are well covered." In a narrow pot, 4 inches of water above the bones should do it, she says; add a couple more inches if your pot is wide. Keller thinks 2 inches is plenty.
The liquid should then be brought to a simmer - slowly, according to most chefs, to maximize flavor extraction; quickly, according to Rodgers. Either way, a gray scum - coagulated protein - will rise to the surface as the water heats and must be rigorously skimmed to produce a clear stock. That's why vegetables and herbs are always added later; they would get in the way of thorough skimming.
Once the stock reaches a simmer, it's unlikely to throw much more scum, so the vegetables and herbs - what chefs call "the aromatics" - can go into the pot. Most agree on carrots, onions, Celery and leeks, cut in chunks of about 1 inch. Cut them the same size, says Keller, "so each vegetable has its proportionate say and one doesn't dominate."
Don't overload chicken stock with vegetables if you want the result to taste like chicken. Peel carrots and onions, and discard Celery leaves, which have a strong flavor. Schwertner uses only the white parts of leeks, not the strappy green tops, arguing that the tops make the stock too vegetal. But she might save the tops, blanch them separately in water, and float them in chicken soup.
A bay leaf, a few sprigs of fresh thyme, and parsley stems go in now. (Parsley leaves, if overused, can give stock a green tinge.) A sprig of mint is a nice idea, says Schwertner, but oily or woody herbs, such as rosemary, are too strong.
"Another don't, and I see people do this all the time, is to put a whole handful of peppercorns in there," says Schwertner. "I don't think they belong in a simmering stock. They turn it quite bitter and taint the color." Instead, she adds a few peppercorns near the end of the cooking time.
Salting prompts another debate, naturally. Some, like Somerville and Rodgers, believe in adding salt early to tease out flavors. Others, like Paul Canales of Oliveto in Oakland, don't salt stock at all, figuring that it's safer to season the dish the stock is used in. A salted stock, if reduced for a sauce, can become too salty, says Canales. But Rodgers says that her own side-by-side test convinced her that a stock seasoned early has "more chickeny-ness" than a stock salted after cooking.
Salted or no, a stock should barely simmer. Adjust the heat so the liquid visibly swirls under the surface and bubbles break the surface leisurely, not rapidly - "a burble," Keller calls it. "The other great stock motion word is that it should be 'smiling.' "
The worst thing you can do to stock is to boil it, says Keller, especially if you haven't skimmed it carefully. "You'll ruin it by emulsifying it," says the chef. "The fat and impurities will mix with the broth, and then you're done."
Once you've got the simmer where you want it, leave the stock alone. Resist the temptation to push the bones and vegetables down into the broth. "Steady, even heat with a minimum of mucking around leads to the best visual clarity," says Rodgers. "Don't stick your wooden spoon in and stir as a nervous habit. You don't get any gain from that."
In three to four hours, chicken stock should have a full, rich, rounded flavor. Taste often and stop when you're satisfied. More simmering will not make it better, says Rodgers, and can even produce flavors you don't want.
Strain the finished stock through a fine-mesh sieve, ladling it from the pot rather than pouring it to be both safe and gentle. Cool to room temperature - in an ice bath to speed the process, if desired - then refrigerate or freeze.
On to fish stock, which has its own requirements but fortunately engenders a little less conflict. Standard practice is to use only the bones of white-meated fish, such as halibut or rock cod. Oily fish like tuna aren't suitable, although Keller says that Jeremiah Tower made a tasty salmon stock for salmon dishes when she worked with him at Stars, the former San Francisco brasserie.
Keller suggests blanching fish bones to remove any trace of spinal-cord blood-"and that," she says, "is after you've rinsed the holy bejeezus out of them." Years ago, as a young chef trying to land a job at Masa's, she learned how perfectionists make fish stock. Showing up for work in her new French chef's jacket, she was shunted off to a small room by the dishwasher with a cleaver and 70 pounds of fish bones. Her task: to split the spines lengthwise and scrape out the bloody contents with a metal brush.
"I was covered with fish blood," recalls Keller, "and I ruined my jacket." But even Keller would agree that home cooks can dispense with scraping fish spines; a good rinse and optional blanching is enough.
Fish heads add body and flavor to stock, but they must be halved and flushed, with the gills removed. Use kitchen scissors to cut around the gills, says Schwertner, but avoid cutting into them or they will make your stock bitter.
As for aromatics, Schwertner likes celery, carrot, leek, fennel and tomato, first sweated in olive oil, with the fish bones on top. Because fish stock cooks briefly - about 20 minutes - the vegetables should be cut small to release flavor quickly. When the fish bones turn white, she adds white wine (it's optional), salt and cold water - just enough to cover the bones. Bring to a simmer, skim, and cook gently just until it tastes good.
"I feel super strongly about not overcooking fish fumet and tasting every few minutes," says Rodgers, using the French work for fish stock. "It's dynamic, the extraction of flavor, and not all the flavors are wonderful. When it's delicious, stop where you're at."
The difficulty of finding humanely raised veal has turned some Bay Area chefs away from veal stock - long a mainstay in serious kitchens - in favor of beef stock or a blended meat stock. Canales mixes pork, beef and chicken for his brodo, or Italian-style meat broth. Schwertner and Keller use a combination of marrow bones for body and meaty bones, such as cross-cut shank, for richness.
For meat stock, which should be dark in color and big in taste, the meat, bones and aromatics are roasted first. Roasting caramelizes them, heightening sweetness and deepening flavor. But any blackening will make meat stock bitter. "You don't want that burned bone thing," cautions Keller.
Stop when the meat, bones and vegetables are a rich auburn color. Transfer meat and vegetables to the stock pot, pour off the fat in the roasting pan, and deglaze it with water to dissolve all the tasty stuck-on bits. Some chefs, Keller among them, add roasted tomatoes or a touch of tomato paste to their beef stock for color and acidity.
Vegetables for meat stock can be cut larger - 2 inches or so - because the stock cooks for so long, at least 6 hours. As with chicken stock, skimming is critical and stirring discouraged. At restaurants, the meat stock often cooks overnight, the heat adjusted so the stock just murmurs.
The vegetables are spent by the end of this process, but the meaty shank still has redeeming value. "It's delicious no matter how long it has cooked," says Schwertner, who sets it aside and enjoys it with mustard or horseradish.
Predictably, there's no consensus on meat stock, either. Canales, for one, adds no aromatics, a position he admits is uncommon. An early mentor, a French chef who had cooked at New York's Four Seasons, persuaded him to omit the usual herbs and vegetables. "He was adamant," says Canales. "He said, 'You're making this stock and then you're going to dilute its meat flavor with aromatics. And then you're going to make soup and further dilute the flavor with more aromatics."
Later he worked at Lutece with the legendary André Soltner, who held similar notions. "A lot of people will throw in leek tops or parsley stems," says Canales, "but (Soltner) always said they made a dingy-looking stock, and it's true."
Vegetable stock, while much faster and easier than meat stock, is just as subject to strong views.
"I hate the way that people think they can throw everything into the pot and make vegetable stock," says Schwertner.
Consider the balance of vegetable flavors and the eventual use of your stock. Portobello mushrooms will yield a stock too dark for many vegetable soups, for example; broccoli and other members of the cabbage family produce a stock that would overwhelm a delicate vegetable risotto. Adding a lot of any one vegetable, just because you have it, will give an unbalanced result, says Somerville.
Schwertner likes to sweat the ingredients for vegetable stock in a little butter or olive oil under a round of parchment, slowly drawing out their sweetness. "It creates a kind of greenhouse environment where moisture stays close to the vegetables and they're not coloring but just softening," she says.
A fall vegetable stock might include carrot, Celery or celery root, leek, fennel, some tomato trimmings, a smidgen of kohlrabi and a few dried porcini. "That's a beautiful sweat," says Schwertner, "and it will smell so lovely. If you just put a bunch of raw vegetables in water and boil it, it's not going to be as delicious as vegetables that have sweated."
Cold water, herbs and Sea Salt go in next, and the stock is simmered "for a very long time," she says. (Others say 45 minutes.) "Decant it very slowly," says Schwertner, "and you'll get a clear vegetable stock that really has flavor."
A weekend of stock making can pay delicious dividends in the coming months, especially if, as Schwertner urges, you mind the details. A carefully made stock "is lovely to look at and lovely to fuss over," she says, "and you want to have that beautiful aroma in your world. It's so therapeutic."
Inside
Recipes F5 & F6
Stock options F6
Storing stock
Stock is highly perishable, especially fish stock. It quickly develops sour or off flavors.
-- For chicken, beef or vegetable stock, immediately freeze what you don't plan to use within 3 to 4 days. Freeze any fish stock you don't plan to use within a day.
-- Use heavy-duty freezer containers with tight-fitting lids. Stock expands as it freezes, so allow about an inch of headspace.
-- Even in a freezer, stock does not last forever. For best quality, try to use it within three months. Lift off any fat congealed on the surface before you thaw it.
- Janet Fletcher
Other stocks for other occasions
Bay Area chefs make a variety of stocks, depending on the needs of their menu and the waste generated by their kitchen.
-- In summer, Loretta Keller of San Francisco's Coco500 makes a corn cob stock for use in vegetarian soups. The corn kernels are removed for other dishes and the naked cobs go into the stockpot with onion, fennel, garlic and herbs.
In fall and winter, when Dungeness crab is in season, she removes the meat from boiled crab and makes a stock with the roasted shells and aromatics - a flavorful base for seafood sauces, soups and risotto.
-- At Boulevard in San Francisco, chef Nancy Oakes makes stock from Parmigiano Reggiano rinds, adding garlic, onions, fennel, celery and thyme. "It's best to wrap the rinds in cheesecloth," says Oakes, "or they turn into a gluey blob that can attach to the bottom of the pan."
She uses the stock for minestrone and other vegetable soups and says it makes an awesome risotto. "It's best with a prosciutto bone," she says. "Then you have ham and cheese stock."
- J.F.
Stock economics
Using the recipe for Basic Chicken Stock, I made 41/2 quarts of stock for $5.70, about $1.25 per quart. The bones cost $4.50; the vegetables and herbs amounted to little more than $1. By comparison, a 491/2-ounce tin of Swanson 99 Percent Fat Free Chicken Broth cost $3.29 at my market, about $2.12 per quart.
For Zuni Chicken Stock, I purchased a whole 51/2-pound organic chicken (just under $16) and about $1 worth of vegetables. The breast on this large bird, which I removed and cooked for dinner the following night, weighed about 11/4 pounds, so let's subtract $3.50 from the price of the chicken. That makes an investment of $13.50, for which I got nine cups of stock ($1.50 per cup). Boxed organic chicken broth at my local market was $3.79 a quart, or about 95 cents per cup.
- Janet Fletcher
Basic Chicken Stock
Makes about 41/2 quarts
You can use a whole bird or parts. If you use a whole bird, remove the chicken breasts first and reserve them for another use. For a more economical stock, use a combination of bony parts with some meat attached, such as carcasses, necks, backs and wings. Many supermarkets can get these parts with some notice. Chinese markets typically have them, as well as chicken feet, which give stock viscosity.
* 5 pounds meaty chicken bones
* 2 medium carrots, peeled, in 1-inch chunks
* 1 rib celery, in 1-inch chunks
* 1 leek, white part only, halved lengthwise and rinsed well, in 1-inch chunks
* 1 large onion, halved and peeled
* 1 clove
* 6 Italian parsley sprigs
* 1 bay leaf
* 2 to 3 sprigs of fresh thyme
* 12 peppercorns
* -- Kosher or Sea Salt
Instructions: Rinse the chicken bones well, removing any bloody bits and clumps of fat. If the pieces are too large to fit comfortably in your stockpot, separate them at a joint with a boning knife. Try not to splinter the bones. Put the chicken parts in a pot with at least an 8-quart capacity. Add just enough cold water to cover the bones, about 5 quarts.
Bring the water just to a simmer over moderately low heat; do not try to speed up the process by raising the heat. Rigorously skim any scum or foam that collects on the surface. When the liquid begins to bubble, add the carrots, celery, leek, onion, clove, parsley sprigs, bay leaf, thyme and peppercorns. Adjust the heat so the liquid barely bubbles; do not allow it to boil or the stock will be cloudy.
Cook gently without stirring for 3 hours. Remove from the heat. Strain the stock through a fine sieve and discard the solids. Season to taste with salt.
Let cool completely, then refrigerate, or freeze in freezer containers.
Due to the nature of the recipe, an accurate analysis is not possible.
Zuni Chicken Stock
Makes 8-10 cups
Adapted from "The Zuni Cafe Cookbook" by Judy Rodgers (W.W. Norton, 2002).
* -- One 5 1/2 pound chicken, preferably with neck and feet, or a smaller dressed chicken plus extra wings to equal 5 1/2 pounds
* -- About 4 quarts cold water
* 1 large carrot, peeled, in 2-inch chunks
* 1 celery rib, leaves removed, in 2-inch chunks
* 1 large onion, root end trimmed, peeled and quartered
* 1 1/2 teaspoons kosher or Sea Salt
Instructions: Remove the giblets from the chicken, if included. Don't remove the lump of fat you find inside the cavity; it will add flavor. Rinse the chicken. Cut the two breast halves off the carcass and reserve for another use. Slash the leg and thigh muscles to encourage the release of flavor. Cut off the feet and neck, if the bird has them. Place the feet, neck and carcass in an 8- to 10-quart stockpot. Add the cold water. If it doesn't cover the chicken, don't add more. Instead, remove the chicken and cut off the legs and wings at the joints, then replace all the parts in the pot, arranging them so they sit low enough to be submerged.
Bring to a simmer over high heat and skim the foam. Stir the chicken under once just to allow the last of the foam to rise, then reduce the heat and skim the foam carefully, leaving behind any fat. Add the vegetables and salt and stir them under. Return to a gentle simmer and adjust the heat to maintain it. Cook without stirring until the broth has a rich, bright, chickeny flavor, about 4 hours.
Turn off the heat and let the stock settle for 1 minute, then pour through a wide strainer. Tipping the hot, heavy pot can be awkward. Start by ladling the stock into the strainer until the pot is light enough to lift and tip. For a clearer stock, restrain through a fine-mesh sieve. Cool to room temperature, then cover and refrigerate or freeze in freezer containers.
Due to the nature of the recipe, an accurate analysis is not possible.
Basic Fish Stock
Makes about 1 quart
* 1 pound meaty white fish bones, such as bones from halibut or sea bass
* 2 tablespoons extra virgin olive oil
* 1 medium carrot, peeled, in small dice
* 1 celery rib, in small dice
* 1 large leek, white part only, halved lengthwise, rinsed well, in small dice
* 1 small tomato, in small chunks
* 1/4 large fennel bulb, in small dice
* -- About 1 dozen Italian parsley stems, broken in half
* 2 to 3 sprigs fresh thyme
* -- Kosher or sea salt
* 1 cup white wine
Instructions: Rinse the fish bones well, removing any traces of blood.
Heat the olive oil in an 8-quart pot over moderately low heat. Add the carrot, celery, leek, tomato, fennel, parsley and thyme. Season with salt and stir to coat with the oil. Arrange the fish bones on top and cook gently without stirring until any meat clinging to the fish bones turns white, about 30 minutes. This slow "sweating" process extracts flavor from the vegetables and makes a sweeter stock.
Add the wine and just enough cold water to cover the bones, about 1 quart. Bring slowly to a bare simmer, then adjust the heat to maintain a gentle bubble; do not allow the stock to boil or it will be cloudy. Cook, tasting often, until the stock has a rich, sweet flavor, 15 to 20 minutes. Do not allow the stock to overcook or it will lose its delicate sweetness.
Strain the stock through a fine sieve, discarding the solids. For an especially clear stock, line the sieve first with a double thickness of cheesecloth. Taste the strained stock and add more salt if necessary. Cool to room temperature, then refrigerate or freeze in freezer containers.
Due to the nature of the recipe, an accurate analysis is not possible.
Basic Vegetable Stock
Makes about 1 1/2 quarts
This recipe doubles easily if you want stock for the freezer.
* 3 tablespoons extra virgin olive oil
* 2 medium carrots, peeled, in small dice
* 2 celery ribs, in small dice
* 1/2 large fennel bulb, in small dice
* 1/2 small celery root, peeled, in small dice
* 2 small tomatoes, in small chunks
* 2 cloves garlic, peeled and smashed
* 3 tablespoons crumbled dried porcini mushrooms
* 1 dozen Italian parsley sprigs
* 4 to 6 sprigs fresh thyme
* 1 bay leaf
* 1 dozen peppercorns
* -- Kosher or sea salt
Instructions: Heat the olive oil in a 6- to 8-quart pot over moderately low heat. Add the carrot, celery, fennel, celery root, tomato, garlic, porcini, parsley, thyme, bay leaf and peppercorns. Season with salt and stir to coat with the oil. Cover the vegetables with a round of parchment paper and "sweat" them slowly, without stirring, for 30 minutes. This process extracts flavor from the vegetables and makes a sweeter stock.
Add 2 quarts cold water and bring slowly to a bare simmer. Adjust the heat to maintain a gentle bubble and cook until the stock is rich and sweet, about 40 minutes. Strain through a fine sieve, discarding the solids. Taste the strained stock and add more salt if necessary.
Cool to room temperature, then refrigerate or freeze in freezer containers.
Due to the nature of the recipe, an accurate analysis is not possible.
Basic Beef Stock
Makes about 6 quarts
Beef stock is time consuming to make, so you may as well make a lot. You'll need a 16-quart pot to hold everything.
* 10 pounds meaty beef bones and marrow bones, such as shin, shank and other leg bones
* 1 large onion, quartered, layers separated
* 2 carrots, peeled, in 1 inch chunks
* 2 celery ribs, in 1-inch chunks
* 2 leeks, halved lengthwise, washed well, in 1-inch chunks
* 1 tablespoon olive oil
* 2 tablespoons tomato paste
* 2 bay leaves
* 1 dozen Italian parsley sprigs
* 6 sprigs fresh thyme
* 1 dozen peppercorns
* 3 tablespoons kosher or sea salt, plus more as needed
Instructions: Preheat the oven to 425°. Rinse the meat and bones well and pat dry. Put them in a large roasting pan, where they should fit snugly in a single layer.
Toss the onion, carrots, celery and leeks with the olive oil to coat them lightly, then put the vegetables in a roasting pan or baking dish where they fit snugly in a single layer. Roast the meat and bones, turning once, until deeply browned and caramelized, about 11/2 hours. Roast the vegetables, stirring occasionally, until well browned in spots, about 45 minutes. Do not let the meat or vegetables blacken or the stock will be bitter. If necessary, remove any vegetables, such as leek tops, that threaten to burn before the other vegetables have browned.
Transfer the vegetables to a large stock pot. Add 1 cup water to the vegetable roasting pan and scrape with a wooden spoon to dislodge any caramelized bits. Pour this liquid into the stock pot.
Transfer marrow bones to the stock pot. Transfer the meaty bones to a platter. Pour off any fat in the roasting pan, leaving the stuck-on bits of protein behind. You will deglaze the pan later.
Coat the meaty bones with the tomato paste and return the meat to the roasting pan. Turn off the oven, then put the roasting pan back in the oven for 20 minutes.
Transfer the meaty bones to the stock pot. Add 2 cups water to the roasting pan, set the pan on the stovetop over moderately low heat, and scrape with a wooden spoon to dislodge any caramelized bits. Pour this liquid into the stock pot.
Add the bay leaves, parsley, thyme, peppercorns and salt to the stock pot, then add enough cold water to cover the bones, 7 to 8 quarts. Bring to a bare simmer slowly over moderately low heat, skimming any foam that collects on the surface. Adjust the heat to maintain a slow bubble. Do not allow the stock to boil or it will be cloudy. Cook without stirring for 6 hours.
Ladle the stock through a strainer into a large bowl or deep plastic container. Discard the solids. If you like, reserve the shank, shin or other meaty bones and serve them with horseradish, mustard or an Italian salsa verde (parsley and caper sauce).
Cool the stock, then refrigerate until chilled. Lift off and discard the fat. Return to the refrigerator, in a lidded container, only the stock that you will use in the next 3 to 4 days. Freeze the remaining stock in freezer containers.