Thoughts on cheese

I have too many rambling thoughts about cheese, so maybe it's best that I just list them:

• It is a terrible loss to the world that the world no longer enjoys cheese made in that artful tradition that evolved over thousands (thousands!) of years. Cheese, yet another casualty of war...
• That being said, I am not opposed to the use of synthetically made rennet as opposed to using the stomach of a young calf. My animal-lover self cannot justify the killing of calves that would be needed to traditionally satisfy the demand for cheese. 
• On the opposite extreme, I am disgusted by the preference to process cheese. It seems like the hot-dog version of cheese. The thing that puts me out is not so much that it exists, but that due to its low cost, it is prevalent in our society. How many times have I consumed this product without even knowing it? Yet another reason to forgo things made with products of unknown origin. 
• And since I am on an emotional rant...low fat cheese, really? When considering what manufacturers have to put into cheese to make it palatable once the fat is out, I no longer wonder why our bodies have traces of harmful pollutants. I do not want to place blame only on manufacturers though. A healthy approach to moderation would diminish the demand for these altered products that seem to scream, "eat all you want, it has only half the calories! The other half is just a bunch of anti-nutrients." How about eating half but really, really enjoying it?

Lemon cheese

As posted in Kitchen chemistry by Dr. Patti Christie, http://ocw.mit.edu/courses/special-programs/sp-287-kitchen-chemistry-spring-2009/readings/MITSP_287s09_read10_Cheese.pdf

From Cheese Making Made Easy by Ricki Carroll and Robert Carroll

This cheese has a delicate flavor of lemon. It is a moist cheese with a spreadable texture. It can be used as a spread or in cooking.

This soft cheese recipe consists of three steps: acidifying and coagulation, draining and mixing, salting and spicing.

Ingredients:

• 1 quart (4 cups) milk
• juice of 2 lemons (about 1/2 cup) or another acidifying agent; orange juice,raspberry vinegar or cider vinegar. 
• salt and herbs

Step 1 : Acidifying and coagulation

• Using a double boiler ( or a metal bowl floating in a pan of water), indirectly heat 1 quart of milk to 170 F. This will take anywhere from 15 minutes to 30 minutes. Make sure all of the milk is at least 170 F.
• Remove the milk from the heat
• Add the lemon juice and let the milk set for 15 minutes. If the milk does not set (i.e. you see the milk proteins precipitated out of solution), add more lemon juice.

Step 2: Draining

• Pour the curds into a cheesecloth-lined colander. Tie the four corners of the cheesecloth into a knot and hang bag to drain for 1 to 2 hours or until the curds have stopped draining. After the initial burst of dripping, this process can be aided by gently squeezing the curds to remove the water. Using this process, you can probably speed up the draining step to 30 minutes.
• You can save the whey. It can be used in cooking, such as baking bread. It is supposedly is a refreshing summer-time drink if it is chilled and served with mint leaves.

Step 3: Mixing, Slating and Spicing

• Take the cheese out of the cheesecloth. You may have to scrape some off the clothe
• The cheese can be lightly salted and herbs may be added if desired.
• One way to season the cheese is to make it into a log and roll it in coarsely ground pepper.
• The yield should be about 6 – 8 ounces of lemon cheese for each quart of milk

Cheese and Health

Cheese is essentially a concentrated milk, so many of the health advantages and disadvantages of milk apply to cheese. It is a rich source of protein, calcium, and energy. The main health concern derives from its high saturated fat content. However, eating cheese as part of a balanced diet is compatible with good health.

Food poisoning

People are often concerned about consuming cheeses made from raw and unpasteurized milk. Cheeses made from unpasteurized milk are required to be aged at least 60 days by law in the US. This requirement extends to imports as well. Cheese in general present a relatively low risk of food poisoning. Soft cheese has the greatest potential for growing pathogens, so even pasteurized versions should be avoided by people vulnerable to infection such as pregnant women, the elderly, and the chronically ill. Hard cheeses are inhospitable to disease microbes and seldom cause food poisoning.

Foreign molds such as Aspergillus versicolor, Penicillium viridicatum, and P. cyclopium occasionally develop on the rinds and contaminate the cheese. Though this problem is rare, it is best to discard the cheese in its entirety. 

Some people are sensitive to amines present in strongly ripened cheese. Histamine and tyramine are found in large quantities in Cheddar, blue, Swiss, and Dutch-style cheeses. Sensitive people may suffer a rise in blood pressure, headaches, and rashes.

Tooth decay

Eating cheese slows tooth decay. It appears that when cheese is eaten at the end of a meal, the calcium and phosphate from the cheese blunt the acid rise of bacteria that adhere to teeth, thus preventing tooth decay.

Process cheese and Low-fat cheese

Process cheese is an industrial version of cheese that makes use of surplus, scrap, and unripened materials. It requires the use of "melting salts" to make it fondue-like. In 1917, Kraft patented a combination of citric acid and phosphates, and a decade later presented the cheddar look-alike Velveeta to the market.

Melting salts are mixtures of sodium citrate, sodium phosphates, and sodium polyphosphates. These salts are mixed with a blend of new, partly ripened, and fully ripened cheeses. The salts  loosen the protein matrix and melt the component cheeses into a homogenous mass. The characteristics and low-cost of process cheese have made it a popular ingredient in fast-food sandwiches.

Low- and no-fat "cheese" products replace fat with various carbohydrates and proteins. These products do not melt. They soften and dry out.

Cooking with cheese

Melting cheese

At around 90°F, the milk fat melts, cheese becomes more supple, and fat beads on the surface. At higher temperatures, around 130°F/55°F for soft cheeses, 150°F/65°C for Cheddar and Swiss types, 180°F/82°C for Parmesan and pecorino, bonds holding the casein proteins together begin to break and the protein matrix collapses. Melted cheese flows as thick liquid. The moisture content dictates the melting behavior of cheese. Low moisture cheeses are more concentrated and intimately bonded, therefore, they require more enegry to melt. After continued heat, moisture evaporates and melted cheese resolidifies.

There are several cheeses that do not melt. They just get stiffer and drier. Examples include Indian paneer, Latin queso blanco, Italian ricotta, and most fresh goat cheeses. All of them are curdled primarily by acid, not rennet. Acid dissolves the calcium glue that hold casein proteins together in micelles along with the negative electrical charge. The proteins bond extensively, so when heated, water is lost first before the protein bonds break. As water boils away, the proteins become even more concentrated. Firm paneer and queso blanco can be simmered or fried like meat.

Stringiness

Melted cheese becomes stringy when mostly intact casein molecules are cross-linked together by calcium into long, fibers that can stretch. If, however, casein has been attacked extensively by enzymes, then the pieces are too small to form fibers, as is the case with well aged cheeses. These do not get stringy. The degree of cross linking is such that casein molecules are tightly bound. The molecules just break.

Stringiness, can be determined by how the cheese was made. Stringy cheeses are moderate in acidity, moisture, salt, and age. They are intentionally made fibrous, as is the case with mozzarella, Emmental, and Cheddar. Crumbly cheeses include Cheshire and Leicester. Caefphilly, Colby, and Jack are preferred for melted preparations. Gruyère is the choice for fondues. Italian grating cheeses, such as Parmesan, grana Padano, and pecorinos have a broken protein fabric which makes them ideal to be disperced in dishes.

When preparing cheese sauces and soups, the aim is to integrate the cheese evenly in the liquid to add richness and flavor to the dish. To avoid stringiness, lumps, and fat separation consider the following tips:

• Avoid using cheese prone to stringiness in the first place. Moist or well-aged grating cheeses blend better.
• Grate cheese finely.
• Heat the dish as little as possible after the cheese has been added. Simmer the ingredients first, cool a bit, then add the cheese.
• Minimize stirring as it can push disperesed particles together.
• Include starchy ingredients that coat proteins and fat pockets, keeping them apart. Use stablizing ingredients such as flour, cornstarch, or arrowroot.
• If the flavor permits, use wine or lemon juice.

Cheese fondue

The ingredients for fondue include an alpine cheese such as Gruyère, a tart white wine, some kirsch, and sometimes starch (for added insurance). The wine contributes water, which keeps the casein proteins moist and dilute, and tartaric acid, which pulls off the calcium and leaves casein glueless and separate. Citric acid from a lemon juice does the same thing.

When using cheese as a topping or gratin, keep in mind that too much heat dehydrates the casein fabric, toughens it, and causes the fat to separate. To avoid this, watch the dish carefully when under the broiler or in the oven, and remove as soon as the cheese melts. If you want to brown a cheese topping, pick a robust cheese such as a grating cheese.

Choosing, storing, and serving cheese

The most important thing to understand is that bulk supermarket cheeses are pale imitations to real, flavorful cheeses. To find good cheeses, buy it from a specialist. Whenever possible, buy portions that are cut to order, as precut portions may be old and their large exposed surfaces develop rancid flavors from contact with air and plastic wrap. Exposure to light also damages lipids, causes off-flavors, and bleaches the annatto in orange-dyed cheeses, turning it pink. Pregrated cheese has tremendous surface area so it looses much of its aroma and carbon dioxide, factors which contribute to the impression of staleness.
Cheese is best stored cool, not cold. It is best kept at 55-60°F/12-15° C; a temperature that extenuates the ripening conditions. It is warmer than the fridge, but cooler than ambient temperatures. The shelf life of cheese is affected by its water content. Fresh cheese with 80% water lasts a few days. Soft cheese, at 45-55% moisture, reaches its prime after a few weeks, semihard cheese at 40-45% after a few months, and hard cheese at 30-40%  moisture after a year or more.

Choose loose wrapping to preserve cheese at its best. Tight wrapping in plastic traps moisture. The restricted oxygen encourages spoilage bacterial and fungal growth. Strong volatiles like ammonia also become trapped and impregnate the cheese instead of difusing out. Whole still developing cheese should be stored unwrapped or loosely wrapped in wax paper. If a piece of cheese develops an unusual surface mold or sliminess or an unusual odor, discard it. Trimming the surface does not remove mold filaments deep in the cheese which may carry toxins and lead to food poisoning.

Cheeses should never be served direct from the refrigerator. At such low temps, milk fat is congealed and hard, the protein network is stiff, and the cheese tastes rubbery and flavorless. Cheese is best served at room temperature unless it is warmer than 80°F/26° C, at which the milk fat metls and sweats out of the cheese.

People often wonder whether the rind of certain cheeses is to be consumed. The rinds of long-aged cheeses are tough and slightly rancid, so avoid eating them. Softer cheeses have rinds that may be eaten, but doing so is a matter of taste and preference.

Making cheese

The artful transformation of milk into cheese occurs in three stages: In the first stage, lactic acid bacteria convert milk sugar into lactic acid. The second stage involves the addition of rennet and the subsequent curdling of the casein proteins and drainage of the watery whey from the concentrated curds. The third stage is ripening. Protein and fat-digesting enzymes present in the milk, from the bacteria and molds, and from the rennet work together to create the unique texture and flavor of the cheese.

Nearly all cheeses are curdled with a combination of starter bacteria acid and rennet. Acid and rennet give different curdle structures. Acid yields a fine, fragile gel; whereas rennet produces a course but robust, rubbery one. Fresh cheeses and small, surface-ripened goat cheeses begin with predominantly acid coagulation. Large semihard and hard cheeses curdle in rennet-dominant coagulation. Cheeses of moderate size and moisture have moderate content of both.

After curdling, the excess water is drained from the curds. For soft cheeses, whole curd is allowed to drain by gravity alone for many hours. The curd of future firmer cheeses is precut to increase surface area and is actively pressed to expel more moisture. Cut curd may also be cooked in its whey to 130° F/55° C to further expel whey and encourage flavor production by bacteria and enzymes. All cheese is later placed into molds and pressed to its final shape and moisture.
Salt is added to new cheese either by mixing it with the curds or applying dry salt or brine to the whole cheese. In addition to taste, salt inhibits the growth of spoilage microbes and acts as a regulator of cheese structure and the ripening process. Salt draws moisture out of the curds and firms the protein structure. Most cheeses contain 1.5 to 2% salt by weight.

Ripening, or affinage, refers to the process of bringing cheese to the point at which flavor and texture are at their best. Cheeses are said to be alive. They begin young and bland, mature into fullness of character, and eventually decay into harshness and coarseness. The length of vitality depends on the type of cheese. The cheesemaker manipulates the maturation process by controlling the temperature and humidity. Specialist cheese merchants in France are also affineurs; they buy freshly made cheese and carefully mature it in their own premises to sell at their best. Industrial producers ripen their cheeses only partly, then refrigerate them to suspend their development before shipping. This technique maximizes shelf life and stability though quality suffers greatly.

The ingredients of cheese

Milk

Cheese is concentrated milk five- to tenfold by the removal of water. The basic character of the milk defines the basic character of the cheese. Milk from cows is more neutral than others. Sheep and buffalo milk have relatively high fat and protein contents therefore make richer cheeses. Goat's milk has less casein protein, so it produces a more crumbly curd.

The cow breed also produces distinct flavors. Today most dairy comes from black and white Holstein or Friesian cows. These cows have been bred to maximize milk yields on a standarized feed. Traditional breeds, such as the Brown Swiss and others, produce a lower volume of milk but one that is richer in protein, fat, and other favorable cheese constituents.

The animal's diet also affects flavor. Today most cows are fed on a standarized diet year round. The diet is composed of silage and hay from few fodder corps such as alfalfa or maize. This feed produces neutral milk that can be made into very good cheese. However, herds allowed to graze on pastures give milk with aromatic complexities that make extraordinary cheese. Pasture cheese has traces of local climate and seasonal flavors. It is also deeper yellow color due to greater carotenoid pigments in fresh vegetation. Beware of bright orange cheeses as these have been artificially dyed.

Flavor is also affected by whether the milk used is raw or pasteurized. Pasteurization, to eliminate disease and spoilage bacteria, has been a practical necessity in industrial cheese making, which requires milk to be pooled and stored. Since 1940s, the FDA requires that any cheese made from unpasteurized milk be aged at least 60 days at a temperature above 35 degrees F/2 degrees C. In the 1950s the US also banned imports of raw-milk cheeses aged less than 60 days. This essentially means that soft cheeses made with raw milk are contraband. The French, Swiss, and Italian regulations actually forbid the use of pasteurized milk for the traditional production of cheeses such as Brie, Camembert, Comté, Emmental, Gruyère, and Parmesan. Pasteurization kills useful milk bacteria, and inactivates enzymes in the milk that work on flavor development. However, pasteurization is no guarantee of safety as milk and cheese can be contaminated in later processing. Most outbreaks in recent years have involved pasteurized products.

Rennet

At least 2,500 years ago, shepherds began using pieces of the first stomach of a young calf, lamb, or goat to curdle milk for cheese. Later, people made a brine extract from the stomach. This was, conceivably, the first semipurified enzyme. Modern methods allow for the production of that same enzyme, chymosin, to be produced in a bacterium, a mold, and a yeast. Most cheese today uses this engineered "vegetable rennets." In Europe, rennet from a calf stomach is required for traditional cheese making.

Traditional rennet is made from the fourth stomach or abomasum of a milk-fed calf less than 30 days old, before chymosin is replaced by other protein-digesting enzymes. Chymosin is unlike other enzymes because it attacks only one milk protein at just one point. It targets the negatively charged kappa-casein that repels individual casein particles from each other. Thus, chymosin allows the casein particles to bond and form a continuous solid gel which is better known as the curd.
Acidity alone reduces the zeta potential and causes milk to curdle, so why rennet? Acid disperses casein proteins and their calcium glue before it allows the proteins to come together. Some casein and most of the calcium are lost in the whey. In addition, the acidity required to curdle milk is so high that some of the flavor-producing enzymes work very slowly or not at all. The curd produced is weak and brittle. By contrast, rennet leaves the casein micelle proteins intact and causes them to bond into a firm, elastic curd.

Microbes

A handful of modern cheese is made with purified cultures, but mostly it is made using a portion of the previous batch's starter.

Starter bacteria consists of lactic acid bacteria which initially acidify the milk, persist in the drained curd, and generate much of the flavor during the ripening process of semihard and hard cheeses such as Cheddar, Gouda, and Parmesan. The numbers of starter bacteria drop dramatically during cheesemaking, but their enzymes continue to work for months. There are two broad groups of starters: Lactococci (mesophilic) and Lactobacilli and Streptococci (thermophilic). Most cheeses are acidified by the mesophilic group, while the few that undergo a cooking step, such as mozzarella and the Italian hard cheeses, are acidified by the thermophilic group.

In addition, there are other microbes that give some cheeses their characteristic looks and flavors:

• The Propionibacteria- Propionibacter shermanii is the hole maker, important in Swiss starters. It produces carbon dioxide gas that makes up the holes in cheese.
• The Smear Bacteria-Brevibacterium linens gives some strong cheeses their characteristic stink, such as Münster, Epoisses, Limburger.
• Molds, especially Penicillium, require oxygen to grow, can tolerate drier conditions than bacteria, and produce powerful protein- and fat-digesting enzymes that improve the texture and flavor of certain cheeses.
• Blue molds include Penicillium roqueforti, which gives Roquefort cheese its veins of blue; and P. glaucum, which colors the interior of Stilton and Gorgonzola.
• White molds include P. camemberti, which contributes to the creamy texture of Camembert, Brie, and Neufchâtel.

History of cheese

Cheesemaking dates back 5,000 years. It is believed to have originated from warm central Asia and the Middle East, as people learned to preserve naturally curdled milk by draining off the watery whey and salting the concentrated curds. There is physical evidence of cheesemaking in Egyptian pots dating to 2300 BCE.

Eventually, the custom moved West and North into Europe. In those cooler regions, people produced many variations of curds that resulted from milder treatments and time. The cheese became alive with different microorganisms. The ancient Columella notes cheese making practices in Europe in his Rei rusticae ("On Rustic Matters") about 65 CE. By the Middle Ages, cheesemaking techniques developed independently in the large feudal estates and monasteries. They suited local conditions and markets. Small, soft cheeses were mostly eaten locally. Large hard cheeses required milk from many animals so cooperatives developed. Gruyère fruiteries began around 1200 CE. Hard cheese was transported long distances and kept indefinitely. The independent producers resulted in a wide variety of cheese. By the 18th century, cheese was considered a stape food, "white meat" for the poor and an integral course in a multicourse feasts for the rich. The golden age of cheese was probably in the late 19th century to the early 20th century when the art was fully matured and railroad transportation made cheese widely available still at its best.
Sadly, industrialization and war brought the demise of traditional cheesemaking. Cheese and butter factories were born in the US, a country with no cheesemaking tradition. By the end of the Civil War there were hundreds of "associated dairies" that manufactured cheese for many farms. Pharmacies, and later pharmaceutical companies, began mass-producing rennet. At the turn of the century, scientists in Denmark, the US, and France standarized cheese making by introducing pure microbial cultures for curdling and ripening cheese. Cheesemaking no longer benefited from the complex flora found in individual farms. According to Harold McGee, in On Food and Cooking, "the crowning blow to cheese diversity and quality was World War II" (p. 54). Dairying in continental Europe was devastated. In the prolongued recovery, factory production of cheese was favored for its economies of scale and regulation. Cheese became inexpensive and standarized. Since then, most of the cheese in Europe and the US is factory made. In 1973, France instituted a certification program for cheese made by traditional methods. Still, less than 20% of French cheese today qualifies for that certification. In the US, most of the market is flooded with factory "process" cheese, made from a mixture of aged and fresh cheeses blended with emulsifiers and repasteurized. "Natural" cheese, though still almost exclusively factory-made, is not as widely consumed.

In the 21st century, cheese consumption is at its highest world wide. However, it has become an industrial product with little resemblance to the age-old art. McGee expresses that "industrial cheese is...a simplified food that could be and is made anywhere, and that tastes of nowhere in particular" (On Food and Cooking, p.54).

In the recent years, there has been a revival of tradition and quality. In the US, artisan cheese is starting to claim a small portion of the market share. What once was considered white meat for the poor, now is a pricey treat for the urban middle class.

Cheese

This week the topic is all about cheese. Sections include:

History of cheese
Components of cheese
Making cheese
Cooking and storing cheese

Hope you join me!

Thoughts on beans and other legumes

When I was growing up, my family always had real Chinese soy sauce. It might have been the only true remnant of our not-so-distant Chinese ancestry. I am not sure who, but someone would travel to Mexico City and buy it from the Chinese market. So it never occurred to me that there would be anything different until we moved to the US and all that was available was Kikkoman soy sauce. This type of soy sauce was watery, milder, and had a funny taste. At the time I thought that it had to do with commercialization and price. Real Chinese soy sauce was obviously much better, so how come all the Chinese restaurants served Kikkoman?

In reading for this lesson, I came to the conclusion that the Kikkoman soy sauce is indeed made after the Japanese soy sauce model which includes a mixture of soybeans and wheat. I grew up on Chinese soy sauce made solely from soybeans, so my palate appreciated the difference. I often wonder whether Americans are afraid of robust flavor because most "ethnic" foods available tend to be milder than the original. Funny enough, my parents never conceded to the Japanese style, and since have found a store in Atlanta that sells real Chinese soy sauce.

On a different, though slightly related note, growing up I never conceived the idea of eating beans from a can. Mexicans are known for eating beans, therefore, Mexicans cook beans. They have these big pots made out of clay in which traditionally beans are cooked. I ought to get one the next time I travel down there. My mom still makes really good beans even without the pot. Before I moved out, I asked my mom to show me how to make some of my favorite dishes. She never said how tricky it was to cook beans. She simply told me to pre-soak and cook on low for a couple of hours. Well, my first attempts turned out to be a mess of gigantic, undercooked beans. I guess my mom did not account for the change in altitude. So after many years of somewhat eradicating my Mexican diet, maybe I should give beans another try. After all, one  really just needs to pre-soak and cook on low for a few hours...

Hearty three-bean chili

As posted on Kitchen Chemistry, by Dr. Patti Christie, from Cooking Light Annual Cookbook, 1996.
http://ocw.mit.edu/courses/special-programs/sp-287-kitchen-chemistry-spring-2009/readings/MITSP_287s09_read09_Chili.pdf

Ingredients:

1 teaspoon vegetable oil
2 cups chopped onion
3 cloves garlic, minced
2 tablespoons chili powder
1 1/2 tablespoons ground cumin
1/2 teaspoon salt
1 (28 oz) can ground tomatoes
2 (15 oz) cans black beans, drained
1 (15 oz) pinto beans, drained
1 (14.5 oz) can broth, vegetable or beef
1/2 cup water
1 large green pepper, cut into 1-inch pieces
1 large sweet red pepper, cut into 1-inch pieces
1/2 cup nonfat sour cream
1/3 cup diced green pepper
1/3 cup diced sweet red pepper

Method:

1. Open the cans of the beans upside down and dump into colander. Opening the cans upside down enables all of the beans to be removed from the can without the use of a spatula. Rinse the beans under running water to remove excess salt.
2. Heat oil in a large Dutch oven over medium-high heat until hot
3. Add onion and garlic; sauté 5 minutes or until onion is tender
4. Stir in chili powder, cumin and salt; sauté 1 minute
5. Add tomato and next 7 ingredients
6. Bring to a boil; cover, reduce heat and simmer 30 minutes, stirring occasionally
7. Ladle chili into individual bowls, and top each serving with 1 tablespoon sour cream
8. Sprinkle diced pepper evenly over each serving

Yield: 12 servings of 1.5 cups each.

Fermented soybean products

Fermented soy products include sufu, miso, soy sauce, tempeh, and natto.  

Fermented bean curd or sufu (tou fu ru, fu ru) is the vegetarian equivalent to mold-ripened milk cheeses.

Most fermented soybean products suffer a two-stage fermentation process where to start, dormant green spores of Aspergillus molds are mixed with cooked grains or soybeans, and kept well aerated and moist. The spores germinate and produce digestive enzymes that break down the beans/grains. After two days, the enzymes are at their peak. The mixture, called chhü in China and koji in Japan, is immersed in salt brine and more cooked soybeans. In this oxygen-poor brine, the molds die, but their enzymes continue to work. To end, anaerobic, salt-tolerant lactic-acid bacteria and yeasts grow in the brine and contribute their own flavorful by-products to the mixture.

Traditionally miso making allows the mixture to ferment for months to years at a warm temperature. Browning reactions generate deeper layers of color and flavor. Modern, industrial production cuts the fermentation and aging from months to weeks, and compensates the resulting lack of color and flavor with additives.

Soy sauce in the West is mostly Japanese soy sauce, which includes an even mixture of soybeans and wheat. The starch from the wheat gives it a characteristic sweetness, higher alcohol content, lighter flavor and color. 

Chinese soy sauce and Japanese tamari are almost exclusively made from soybeans. It is darker in color and richer in flavor due to the higher concentration of soybean amino acids. 

“Chemical” soy sauce is a non-fermented approximation of soy sauce that uses defatted soy meal left over from soybean oil production and is hydrolyzed with concentrated hydrochloric acid. The mixture is neutralized with sodium carbonate and later flavored and colored with corn syrup, caramel, water, and salt. To make it more palatable, it is blended with some portion of genuine fermented soy sauce. To ensure buying genuine soy sauce, avoid labels containing added flavorings and color.

Tempeh originated from Indonesia and is a perishable main ingredient, not a preserved condiment. It is made by cooking the whole soybeans, placed in thin layers, and fermented with a mold. The mold forms hyphae that binds the beans together and digests proteins and fats that turns it into flavorful bits. Fresh tempeh develops a nutty, almost meaty flavor when sliced and fried.

Natto, like tempeh is a perishable product. It is notably alkaline and develops a sticky, slippery slime that can be drawn with the tip of a chopstick into threads up to 3 ft/1 m long. It is made from whole cooked beans and inoculated with a culture of Bacillus bacteria and held at warm temperatures for 20 hrs. Its stringiness derives from long chains of glutamic acid and long branched chains of sucrose.

Palatable soybean forms (non-fermented)

• A few legumes are parched in dry heat to create a crisp texture. Peanuts are the most commonly roasted legumes, but soybeans and chickpeas are also roasted.
• Fresh soybeans are more palatable before they fully mature. Fresh soybeans, Japanese edamame, or Chinese mao dou are special varieties harvested at 80% maturity. They have lower levels of gassy and antinutritional substances.  The beans are sweet, crisp, and green. They are boiled for a few minutes in salted water. Green soybeans are around 15% protein and 10% oil.
• Soy milk has become a popular alternative to cow’s milk, though it must be fortified with calcium to make it an adequate substitute.
• The traditional method of making soy milk involves soaking the beans until soft, grinding them, and either sieving out the solids and cooking the milk (China) or cooking the slurry, then sieving out the solids (Japan). This process produces milk with a strong soy flavor.
• Modern method minimizes enzyme action and soy flavor. The dry beans are soaked, then either cooked quickly at 180-212 degrees F/80-100 degrees C before grinding, or grinding them at that temperature. 
• Bean curd or Tofu is curdled soy milk, a concentrated mass of protein and oil formed by coagulating the dissolved proteins with salts. Invented in China around 2,000 years ago, the Chinese have traditionally coagulated with calcium sulfate. The Japanese and coastal regions of China coagulate it with nigari, a mixture of magnesium and calcium salts that are left over after sodium chloride is crystallized from seawater.
• To make it, soy milk is cooled to 175 degrees F/78 degrees C, and then coagulated with salts. The curd is pressed to form a continuous mass. Commercially, it is cut in blocks and pasteurized.
• Freezing bean curd is a useful application as it concentrates the proteins. Once thawed, the liquid leaks out, and leaves a spongy network that is ready to absorb other flavors. It also develops a chewier, meatier texture.

Soybeans and health

In On Food and Cooking, Harold McGee describes the soybean as

“exceptionally nutritious, with double the protein content of other legumes, a near ideal balance of amino acids, a rich endowment of oil, and a number of minor constituents that may contribute to long-term health.” page 493.

Soybeans contain storage forms of isoflavones. These are phenolic compounds are liberated by intestinal bacteria as phytoestrogens, a form that resembles the hormone estrogen. Boiled whole beans contain the most isoflavones. Some research suggests that they may slow bone loss, prostate cancer, and heart disease, but due to their hormone-like effects on the body, soybeans can worsen pre-existing breast cancer. This process is not completely understood.

Soy beans are also a rich source of saponins, which are soap-like defensive compounds that are both, water- and fat-soluble. Soy saponins bind cholesterol so that the body can’t absorb it efficiently. Furthermore, soybeans have phytosterols, chemical relatives of cholesterol, which also interfere with cholesterol absorbtion.

For all their goodness, soybeans are at the same time, unappealing. They contain abundant antinutritional factors, fiber, and oligosaccharides. They contain negligible amounts of starch. Their texture tends to remain firm. To make them more appealing, the Chinese and others have developed ways to alter their taste, such as via extraction of the protein and fermentation.

Common legumes (not including peanuts)

Fava or Broad Beans – Vicia faba – are the largest legume. They originated in Asia and are believed the earliest domesticated plant. Evidence of cultivation found in Mediterranean sites date back to 3000 BCE. Today, China is the world’s largest producer.

People who have an inherited G6PD deficiency should not consume fava beans as they can develop a hemolytic reaction called “favism.”  Fava beans contain two unusual amino-acid relatives, vicine and convicine, which are oxidants that become toxic to people with an inadequate supply of glutathione, as are people with G6PD deficiency. Favism is found most commonly in the southern Mediterranean and Middle East. In areas where malaria has been historically endemic, G6PD deficiency appears to have been a result of natural selection, as it suppresses the growth of the malaria parasite in red blood cells.

Chickpea/Garbanzo is native of southwest Asia. Two main varieties are available: desi and kabuli. Desi are small, thick, tough seed coat, and dark. These are mainly grown in Asia, Iran, Ethiopia, and Mexico. The kabuli type is most common in the Middle East and Mediterranean. It is larger, cream-colored, with a light seed coat. Chickpeas have 5% oil by weight compared to 1-2% of other legumes.

Hummus is a chickpea paste usually flavored with garlic, paprika, and lemon. Chickpeas are the most important legume in India.

Common bean is native of southwestern Mexico, and most widely consumed in Latin America. The common bean has developed hundreds of varieties. Large varieties originally from the Andes, include kidney, cranberry, large red, and white. Smaller-seeded Central American types include pinto, black, small red, and white.

Popping bean or nuña is cultivated in the high Andes. It can be popped in 3-4 min of high dry heat (i.e. microwave). It does not expand as much as popcorn as it remains fairly dense, with powdery texture and nutty flavor.

Lima bean originated from Peru (named for its capital of Lima). It was introduced to Africa via the slave trade, where today they remain the main legume in the African tropics. Some wild types contain potentially toxic quantities of cyanide, so they must be cooked thoroughly to be safe. Commercial varieties are cyanide-free.

Tepary beans are native of the American southwest, and are unusually tolerant of heat and water stress. They are rich in protein, iron, calcium, and fiber. Tepary have a distinctive sweet flavor.

Lentil is probably the oldest cultivated legume. Native of Southwest Asia, there are two groups: large flat (>5mm across) and small rounded (<5mm). Large are most commonly grown. Varieties include brown, red, or green seed coats. Their flat shape and thin seed coats allows water to penetrate easily, thus they cook quickly, in  one hour or less.

Peas are a cool climate legume. Historically, peas have been an important protein source in Europe, especially around the Middle Ages, from when the following children’s rhyme came: “Pease porridge hot, Pease porridge cold, Pease porridge in the pot, Nine days old.”

There are two main varieties: smooth and wrinkly. Smooth makes for dried and split peas. Wrinkly has higher sugar content, and are usually eaten immature as a green vegetable.

Black-eyed pea/cowpea is not really a pea, but an African relative of the mung bean, brought to the southern US with the slave trade. It has a characteristic eye-like anthocyanin pigmentation around the hilum.

The pigeon pea is distant relative of the common bean. It is native to India. It has tough, reddish brown seed coat.

The “Grams” include several small seeded, quick-cooking beans. The green gram or mung beans are native to India, and widely grown in China. Grams also include the rice bean and the African bambara groundnut.

The azuki bean is an East Asian species of deep maroon color. It is mainly cultivated in Korea, China, and Japan. Azuki are a favorite sprouting seed, and are candied in Japan.

Lupins are mostly found in Italy. They are unusual because they contain no starch and 30-40% protein, 5-10% oil, and up to 50% soluble, but indigestible carbohydrates. They require special processing as many have toxic alkaloids. L. mutabilis is grown in the Andes and has a protein content approaching 50% of the dry seed weight.

Soybeans are the most versatile legume. Domesticated in China more than 3,000 years ago, the soybean spread widely as a staple food throughout Asia encouraged by the vegetarian doctrine of Buddhism. It only became known to the West until after the 19^th century. Today the US supplies half of the world production. However, most US soybeans feed livestock, not people, and much is processed for manufacturing purposes.

A note on hard beans

“Hard-seed” beans occur when temperatures are high, but humidity and water supply are low during the growing season. The outer seed coat gets very water-resistant. Hard-seed beans are smaller than normal and can be picked out before cooking.

“Hard-to-cook” beans are normal when harvested, but become resistant to softening when they are stored for a prolonged time (months) at warm temperatures in high humidity. This results from changes in the bean cell walls and interiors, including the denaturation of storage proteins and the formation of a water-resistant coating around the starch granules. There is no way to reverse these changes and no way of spotting them before cooking. Once cooked, they are smaller than normal and can be picked out.

Presoaking

Presoaking the dried beans in water can reduce the cooking time by more than 25%.

Heat penetrates a dry seed faster than water. If cooked directly from the dry state, much of the cooking time is spent waiting for water to get to the center. Meanwhile, the outer portions of the bean overcook and become fragile. Presoaking helps by allowing the water to reach the center first, before the heat cooks them.  

Soaking times depend on temperature. It is helpful to blanch the beans for 1.5 minutes in boiling water and then allowed to soak in the cooling water for two or three hours. Blanching rapidly hydrates the seed coat that controls water movement. If soaked in cool water, it takes 10-12 hrs before beans double in size.

Salt and baking soda speed cooking. Salt concentration at 1% (10g/l or 2 tsp/qt) speeds cooking greatly. Sodium displaces magnesium from the cell wall pectins and makes them more easily dissolved. Baking soda at 0.5% (1 tsp/qt) can reduce cooking time by 75%. It also contains sodium and its alkalinity facilitates the dissolving of cell-wall hemicelluloses. These additions, however, have an effect on the taste and texture of the cooked beans. Baking soda can give a slippery mouth feel and soapy taste. Salt reduces the swelling and gelation of starch granules within the beans, so the texture is mealy instead of creamy.

Cooking legumes

Fresh shell beans cook fairly quickly, in 10-30 min. Peas, lima beans, cranberry beans, and soybeans (edamame) are the legumes most commonly eaten fresh. Whole dried beans and peas take one to two hours to cook. Their larger size and water intake affect cooking time. Initially, water can only enter through the beans through the hilum, the little pore on the curved back of the bean. After 30-60 minutes, the seed coat has fully hydrated and expanded so that water flowing can pass across the entire seed coat surface, though the rate of flow is still limited.

The liquid in which legumes are cooked greatly affects both, the quality of the cooked beans and the time it takes to cook them. The greater the volume of cooking water, the more color, flavor, and nutrients are leached out of the beans, and the more they are diluted. Beans are best cooked in just enough water to soak up and to cook in.

Take into account the following:

• Boiling water speeds cooking, but damages seed coats and cause the beans to disintegrate.
• Temperatures below boiling (180-200 degrees F/80-93 degrees C) are gentler and better maintain bean structure.  
• Hard water with high levels of calcium or magnesium reinforces the bean cell walls, so cooking takes longer and may prevent the beans from softening fully.
• Acidity slows the dissolving of the cell wall pectins and hemicelluloses, so it slows the softening process but it helps maintain structure.
• Alkalinity does the reverse; it enhances the softening process.
• Sugar reinforces cell-wall structure and slows the swelling of the starch granules. It also helps maintain structure.
• Salt in the water slows the rate at which the beans absorb water, but it does get absorbed eventually. If beans are pre-soaked in salted water, they cook much faster.
• High altitude lowers the boiling point, so cooking dry beans is prolonged.

Note: ingredients such as molasses, which are somewhat acidic and rich in sugar and calcium, and acidic tomatoes can preserve bean structure during long cooking and reheating, such as in baked beans.

Legumes and flatulence

Many legumes contain large amounts of indigestible carbohydrates, such as oligosaccharides and cell-wall cements. The human body cannot break down these carbohydrates; therefore, they pass through the stomach in their complex form. Resident, symbiotic bacteria in the intestine break them down into absorbable forms. The increased growth and metabolism of the intestinal bacteria cause a sudden increase in gas production. 

Cooks can help minimize flatulence by manipulating legumes before consumption. Prolonged cooking helps break down much of the oligosaccharides and cell-wall cements into digestible single sugars. Oligosaccharides are also broken down during germination and fermentation, so sprouts, miso, soy sauce, and extracts like bean curd are less offensive than whole beans.

Legume structure and composition

Legume seeds consist of an embryonic plant surrounded by a protective seed coat. The embryo is made up of two large storage leaves, the cotyledons, and a tiny stem. The cotyledons are a transformed endosperm that provide the bulk of nourishment. The seed coat is interrupted at the hilum, a small depression where the seed is attached to the pod. It is through the hilum that the legume absorbs water.

Most beans and peas are mainly protein and starch, except soybeans and peanuts which have large contents of oil (between 25% and 50% respectively).

The colors of beans and peas are determined mainly by anthocyanin pigments in the seed coat. Solid reds and blacks survive cooking, while mottled patterns become washed out when their pigments leak into adjacent non-pigmented areas and into the cooking water. Color intensity is best preserved by cooking the beans in just enough water to keep them covered. It is best to add water only as needed to keep them barely covered.

Importance of legumes

Legumes have a high content of protein, two to three times that of wheat and rice. Their protein develops from a symbiotic relationship with species of the Rhizobium bacteria, which invade the roots of legume plants and convert nitrogen in the air into a form that is directly usable by the plant to make amino acids.

As a vegetable source of protein, legumes have been highly prized throughout history. No other food item has been so notably honored. Each of the four major legumes known to Rome lent its name to a prominent Roman family: Fabius (fava bean), Lentulus (lentil), Piso (pea), and Cicero (chick pea).

Legumes have been domesticated for thousands of years. Some date back to 3000 BCE. Today they make up staple ingredients in many food cultures.

Beans and other legumes

This week the topics are all about legumes. Topics include:

Legume overview
Common legumes
Cooking beans
Soybeans
Soybean products

Hope you join me!