Chemistry & The Kitchen & Everyday Substitutions

 

Dairy

Flavor and texture are important considerations when substituting dairy products. When working with liquids, you can easily doctor consistency, thickening milk with a little flour or cornstarch to mimic half-and-half, or thinning out Greek yogurt with water to replicate milk. The ingredients below are ordered from thinnest to firmest; if you don’t have the desired substitute for a specific item, move up or down the list.

Ingredient Substitution

Milk Half-and-half or heavy cream thinned with water, evaporated milk, light coconut milk, light cream, oat milk, nut milk, soy milk.

Half-and-Half Thicken milk with a little cornstarch or flour (about 1 tablespoon per cup of liquid) or thin heavy cream with a splash of water.

Heavy Cream For 1 cup heavy cream, use 3/4 cup milk and 1/4 cup melted butter, or thicken 1 cup milk with 1 to 2 tablespoons cornstarch or flour. (Whisk milk into cornstarch or flour little by little.)

Coconut milk, coconut cream (beware of increased sweetness), or cream cheese whisked with a little water also work. Note: Alternatives won’t whip into fluffy whipped cream.

Buttermilk For 1 cup buttermilk, add 1 tablespoon fresh lemon juice (or light vinegar, such as white, white wine or champagne) to a measuring cup and add enough milk to reach 1 cup. Alternately, thin one part yogurt, sour cream or other creamy dairy product with one part milk, or thin two parts yogurt or other creamy dairy product with one part water.

Butter If using butter to conduct heat, as in pan-frying, use olive oil or other fats. (See Oils and Fats below.) For flavor substitutions, like butter in risotto or polenta, a number of creamy options like heavy cream or mascarpone will work.

Creamy Dairy Products Tangy, textural ingredients like crema, crème fraîche, mascarpone, Neufchâtel, Quark, queso fresco, sour cream or yogurt of any variety can be used interchangeably.

CHEESES

There are so many cheeses it’s impossible to cover them all. When substituting, think about its purpose: Will it melt evenly in a pasta sauce, or spread easily on toast? If cooking, swap in one with a similar texture, but if using as an accent, there’s much more flexibility. Here are widely available cheeses (predominantly cow’s milk) broken into broad categories:

Types Examples

Fresh, unripened cheese (soft and wet) Cottage cheese, cream cheese, fromage blanc, ricotta

Soft-ripened cheese (creamy) Brie, Camembert, Pont l’Evêque, taleggio

Semifirm or semisoft cheeses Cheddar, Colby, Edam, fontina, Gouda, Havarti, Jarlsberg, Monterey

Jack, mozzarella, Muenster, pepper Jack, Port-Salut, Swiss

Hard aged cheeses Asiago, Comté, Gruyère, Manchego, Parmesan, pecorino

Oils and Fats

Oils and fats all have a temperature at which they begin to burn, called a smoke point: Neutral oils with high smoke points won’t burn when exposed to high temperatures (as in deep-frying or pan-frying), whereas butter and other solid fats (with low smoke points) burn easily. Here, oils and fats have been grouped into three categories with that in mind. While many of the oils and fats in each category are interchangeable, you’ll want to consider flavor and smoke point when choosing a substitute.

Type Smoke Point Examples

Neutral oils  High Canola oil, coconut oil, corn oil, grapeseed oil, peanut oil and vegetable oil.

Flavored oils  Medium-high Avocado oil, nut oils, olive oil, sesame oil, sunflower oil.

Solid fats Low Bacon fat, butter, chicken fat, lard, margarine and vegetable shortening. Solid when refrigerated but liquid when hot, ghee (clarified butter) has a very high smoke point similar to neutral oils.

Stock

Though stock improves flavor, its primary purpose is to add liquid. If the recipe calls for a little stock, you can substitute water. If the recipe calls for a lot of stock, use water seasoned with one of the ingredients below, keeping the flavors of your recipe in mind. Start small and taste as you go, especially since some items skew significantly sweet, salty or condensed. Substitutions include water seasoned with beer or white wine, juice (such as orange juice or apple juice), melted butter, milk (dairy, coconut, nut or soy milk), miso paste, mushroom stock (liquid from soaked dried mushrooms), olive oil, soy sauce or tea.

Greens

Most greens can be defined by their flavor and texture: Are they bitter or mild? Sturdy or tender? When choosing a substitute, consider how the greens are being used. Tender greens are often consumed raw while sturdy ones might need to be cooked longer; simply add the greens earlier or later in the cooking process as needed.

Type  Examples

Mild and Tender Chard, lettuce, mâche, mesclun, spinach, tatsoi

Mild and Firm Bok choy, cabbage, collard greens

Bitter and Tender Arugula, endive, frisée, mizuna, radicchio, radish greens, watercress

Bitter and Firm Escarole, kale, mustard greens, turnip greens

Vegetables

Substituting vegetables can be tricky, and depends largely on taste. But some can definitely step in for others: say brussels sprouts for broccoli. Just bear in mind texture, moisture content and density. We’ve broken common vegetables up into two categories, based on cook times: Many in the same category cook at a similar rate, but if you’d like to substitute a firm vegetable for a quick-cooking one or vice versa, increase or decrease cook time by adding the ingredient earlier or later in your recipe.

QUICK-COOKING (LESS DENSE)

Asparagus, cabbage (bok choy, broccoli, broccolini, brussels sprouts, cauliflower, kale), celery, corn, eggplant, fennel, mushrooms, peas, peppers, summer squash, zucchini.

SLOWER-COOKING (MORE DENSE)

Root vegetables (beet, carrot, celery root, parsnip, potato, sweet potato, turnip), winter squash (such as butternut squash, delicata, kabocha, pumpkin).

ALLIUMS

Leeks, onions (red, white or yellow), scallions, shallots and spring onions are largely interchangeable. (Garlic’s pronounced flavor makes it difficult to find an exact substitute.) Garlic and onions are available in dried form (powdered, granulated or dehydrated as flakes), which are infinitely more potent — and can skew bitter if overused. Substitute dried ingredients in place of fresh with moderation, and only when the fresh is called for in smaller quantities rather than bulk.

Herbs

Fresh herbs fall into two categories: tender, bright herbs (basil, chervil, chives, cilantro, dill, mint, parsley and tarragon), which are most flavorful when fresh, or woody, savory herbs (bay leaves, marjoram, oregano, rosemary, sage and thyme), which are better dried. Since dried herbs are more potent, substitute 1 teaspoon dried for 1 tablespoon chopped fresh. In general, you can swap one tender herb for another (or vice versa), but substituting a woody herb for a tender herb (or vice versa) works less well. Rely on preference and availability when picking a substitute.

Ingredient Substitutions

Basil Chervil, cilantro, dill, Italian seasoning, oregano, mint, parsley

Bay Leaves Herbes de Provence, oregano, rosemary, sage, thyme

Chervil Basil, dill, parsley, tarragon

Chives Cilantro, garlic powder, onion powder, parsley

Cilantro Basil, chives, parsley, mint

Dill Basil, chervil, mint, parsley

Marjoram Herbes de Provence, Italian seasoning, oregano, rosemary, sage, thyme

Mint Basil, cilantro, dill, parsley

Oregano Bay leaves, herbes de Provence, Italian seasoning, rosemary, thyme, sage

Parsley Basil, chervil, chives, cilantro, dill, Italian seasoning, mint, tarragon

Rosemary Bay leaves, herbes de Provence, oregano, thyme, sage

Sage Bay leaves, herbes de Provence, oregano, rosemary, thyme

Tarragon Chervil, parsley

Thyme Bay leaves, herbes de Provence, oregano, rosemary, sage

Spices

When swapping spices, think about what will work in your dish. Most spices can be grouped into four flavor profiles: earthy, floral, peppery and warm. You’ll often be able to substitute a spice that hits the same notes by picking one with the same qualities.

Type Examples

Earthy Curry powder, garlic powder, onion powder, turmeric, Vadouvan, za’atar.

Floral Cardamom, coriander, fennel, lavender, nutmeg, saffron, star anise

Peppery Allspice, ground ginger, peppercorns, mustard powder, sumac

Warm Cinnamon, chile (dried), chili powder (blend), cloves, cumin, nutmeg, paprika

When it comes to spice, there is ample room for experimentation. Consider layering flavor carefully by seasoning lightly at the start of cooking so the end result is subtle, that way you can increase the spice to taste, if desired, once your dish is fully cooked.

Ingredient Substitutions

Allspice Combine cinnamon, cloves and nutmeg, or use any one of the three

Cardamom Coriander, fennel, ginger, lavender

Cayenne Aleppo pepper, chili powder, dried chiles, hot sauce, paprika, red-pepper flakes, sumac

Chili Powder Combine paprika (sweet, hot or smoked), onion powder, garlic powder, cumin, oregano and cayenne or red-pepper flakes; or use another warm spice, such as cayenne, cloves, cumin, nutmeg or paprika (sweet, hot or smoked)

Cinnamon Allspice, apple pie spice blend, cloves, coriander, nutmeg, pumpkin pie spice blend

Cloves Allspice, cinnamon, nutmeg, black pepper

Coriander Cardamom, cinnamon, fennel, nutmeg, saffron, turmeric

Cumin Chili powder, coriander, curry powder, garlic powder, onion powder, turmeric

Ginger Allspice, cinnamon, cloves, coriander

Nutmeg Allspice, cinnamon, cloves, ground ginger

Paprika Cayenne, chili powder, curry powder, black pepper

Turmeric Curry powder, garlic powder, onion powder, Vadouvan, za’atar

Meat and Seafood

While many home cooks plan meals around a protein, even that’s flexible. Make protein substitutions according to preference and what you have on hand, and shift cook times accordingly. Or adjust the size of the protein by cutting it into smaller pieces (or remove the meat from the bones) so it cooks faster, or leaving it in larger pieces so it cooks at a slower rate. Thinking broadly can expand your options even further: Tofu, lentils, beans and other vegetarian options can make excellent substitutes.

BEEF

If swapping one cut of beef for another, try to substitute tough cuts (like chuck, brisket or round roast) for other tough cuts, and tender cuts (like strip steak, flank steak or filet mignon) for other quick-cooking cuts. You can also use lamb in place of beef in many recipes, though its flavor is more assertive.

GROUND MEAT OR FRESH SAUSAGE

Both can be used interchangeably. You can remove sausages from their casings, and cook them as ground meat, or flavor plain ground meat with red-pepper flakes, fennel seed, Italian herbs and other seasonings. You can also substitute ground meat of any kind, swapping in ground pork for ground beef in meatballs, or ground chicken for ground turkey in a larb, for example. But bear in mind the fat content of whatever you’re using: Ground pork is the fattier option; if cooking with ground beef, chicken, turkey or veal, you might want to add extra oil to provide extra fat

PORK

Bone-in pork chops cook in roughly the same time as steaks of similar thickness, but you will want to use a meat thermometer to check the temperature to achieve desired doneness. If working with diced pork stew meat, cubed beef stew meats will cook at a similar rate. Cubed chicken will also work, but you’ll need to reduce cooking times.

CHICKEN

You can substitute whole boneless, skinless breasts for boneless, skinless chicken thighs: Just butterfly the breasts or pound them thinly to achieve a similar thickness of thighs. (You may also need to adjust cook time.) If substituting bone-in, skin-on thighs, increase the cook time. Ground turkey or turkey breasts also achieve similar results as their chicken counterparts

SEAFOOD

Most fish fillets are either lean (bass, catfish, cod, flounder, halibut, monkfish, red snapper, skate, sole, tilapia) or fatty (char, mahi-mahi, salmon, swordfish, tuna). Substitute lean for lean, and fatty for fatty.

Fresh or frozen shrimp cook very quickly at similar rates and benefit from quick, high-heat cooking methods. Depending on your recipe, fish fillets or small pieces of meat or poultry also might be suitable substitutes.

Ingredient

Amount

Substitution

Allspice

1 teaspoon

1/2 teaspoon cinnamon, 1/4 teaspoon ginger, and 1/4 teaspoon cloves

Arrowroot starch

1 teaspoon

1 tablespoon flour OR 1 teaspoon cornstarch

Baking mix

1 cup

1 cup pancake mix

Baking powder

1 teaspoon

1/4 teaspoon baking soda plus 1/2 teaspoon cream of tartar OR 1/4 teaspoon baking soda plus 1/2 cup buttermilk (decrease liquid in recipe by 1/2 cup)

Baking soda

1 teaspoon

4 teaspoons baking powder OR 1 teaspoon potassium bicarbonate and 1/3 teaspoon salt. NOTE: If the recipe calls for an acidic liquid such as sour cream, yogurt, buttermilk, vinegar, molasses, or citrus juice, you should replace it with the same amount of whole milk

Beer

1 cup

1 cup nonalcoholic beer OR 1 cup chicken broth

Brandy

1/4 cup

1 teaspoon imitation brandy extract plus enough water to make 1/4 cup

Bread crumbs

1 cup

1 cup cracker crumbs OR 1 cup matzo meal OR 1 cup ground oats

Broth: beef or chicken

1 cup

1 bouillon cube plus 1 cup boiling water OR 1 tablespoon soy sauce plus enough water to make 1 cup OR 1 cup vegetable broth

Brown sugar

1 cup, packed

1 cup white sugar plus 1/4 cup molasses and decrease the liquid in recipe by 1/4 cup OR 1 cup white sugar OR 1 1/4 cups confectioners' sugar

Butter (salted)

1 cup

1 cup margarine OR 1 cup shortening plus 1/2 teaspoon salt OR 7/8 cup vegetable oil plus 1/2 teaspoon salt OR 7/8 cup lard plus 1/2 teaspoon salt

Butter (unsalted)

1 cup

1 cup shortening OR 7/8 cup vegetable oil OR 7/8 cup lard

Buttermilk

1 cup

1 cup yogurt OR 1 tablespoon lemon juice or vinegar plus enough milk to make 1 cup

Cheddar cheese

1 cup shredded

1 cup shredded Colby cheddar OR 1 cup shredded Monterey Jack cheese

Chervil

1 tablespoon chopped fresh

1 tablespoon chopped fresh parsley

Chicken base

1 tablespoon

1 cup canned or homemade chicken broth or stock. Reduce liquid in recipe by 1 cup

Chocolate (semisweet)

1 ounce

1 (1-ounce) square of unsweetened chocolate plus 4 teaspoons sugar OR 1 ounce semisweet chocolate chips plus 1 teaspoon shortening

Chocolate (unsweetened)

1 ounce

3 tablespoons unsweetened cocoa plus 1 tablespoon shortening or vegetable oil

Cocoa

1/4 cup

1 (1-ounce) square unsweetened chocolate

Condensed cream of mushroom soup

1 (10.75-ounce) can

1 (10.75-ounce) can condensed cream of celery, cream of chicken, or golden mushroom soup

Corn syrup

1 cup

1 1/4 cup white sugar plus 1/3 cup water OR 1 cup honey OR 1 cup light treacle syrup

Cottage cheese

1 cup

1 cup farmer's cheese OR 1 cup ricotta cheese

Cracker crumbs

1 cup

1 cup bread crumbs OR 1 cup matzo meal OR 1 cup ground oats

Cream (half and half)

1 cup

7/8 cup milk plus 1 tablespoon butter

Cream (heavy)

1 cup

1 cup evaporated milk OR 3/4 cup milk plus 1/3 cup butter

Cream (light)

1 cup

1 cup evaporated milk OR 3/4 cup milk plus 3 tablespoons butter

Cream (whipped)

1 cup

1 cup frozen whipped topping, thawed

Cream of tartar

1 teaspoon

2 teaspoons lemon juice or vinegar

Crème fraiche

1 cup

Combine 1 cup of heavy cream and 1 tablespoon of plain yogurt. Let stand for 6 hours at room temperature

Egg

1 whole (3 tablespoons or 1.7 oz)

2 1/2 tablespoons of powdered egg substitute plus 2 1/2 tablespoons water OR 1/4 cup liquid egg substitute OR 1/4 cup silken tofu pureed OR 3 tablespoons mayonnaise OR half a banana mashed with 1/2 teaspoon baking powder OR 1 tablespoon powdered flax seed soaked in 3 tablespoons water

Evaporated milk

1 cup

1 cup light cream

Farmer's cheese

8 ounces

8 ounces dry cottage cheese OR 8 ounces creamed cottage cheese, drained

Fats for baking

1 cup

1 cup applesauce OR 1 cup fruit puree

Flour: bread

1 cup

1 cup all-purpose flour plus 1 teaspoon wheat gluten

Flour: cake

1 cup

1 cup all-purpose flour minus 2 tablespoons

Flour: self-Rising

1 cup

7/8 cup all-purpose flour plus 1 1/2 teaspoons baking powder and 1/2 teaspoon of salt

Garlic

1 clove

1/8 teaspoon garlic powder OR 1/2 teaspoon granulated garlic OR 1/2 teaspoon garlic salt, reduce salt in recipe

Gelatin

1 tablespoon, granulated

2 teaspoons agar agar

Ginger (dry)

1 teaspoon

2 teaspoons chopped fresh ginger

Ginger (fresh)

1 teaspoon, minced

1/2 teaspoon ground dried ginger

Green onion

1/2 cup , chopped

1/2 cup chopped onion OR 1/2 cup chopped leek OR 1/2 cup chopped shallots

Hazelnuts

1 cup whole

1 cup macadamia nuts OR 1 cup almonds

Herbs (fresh)

1 tablespoon chopped fresh

1 teaspoon (chopped or whole leaf) dried herbs

Herring

8 ounces

8 ounces of sardines

Honey

1 cup

1 1/4 cup white sugar plus 1/3 cup water OR 1 cup corn syrup OR 1 cup light treacle syrup

Hot pepper sauce

1 teaspoon

3/4 teaspoon cayenne pepper plus 1 teaspoon vinegar

Lard

1 cup

1 cup shortening OR 7/8 cup vegetable oil OR 1 cup butter

Lemon grass

2 fresh stalks

1 tablespoon lemon zest

Lemon juice

1 teaspoon

1/2 teaspoon vinegar OR 1 teaspoon white wine OR 1 teaspoon lime juice

Lemon zest

1 teaspoon

1/2 teaspoon lemon extract OR 2 tablespoons lemon juice

Lime juice

1 teaspoon

1 teaspoon vinegar OR 1 teaspoon white wine OR 1 teaspoon lemon juice

Lime zest

1 teaspoon

1 teaspoon lemon zest

Macadamia nuts

1 cup

1 cup almonds OR 1 cup hazelnuts

Mace

1 teaspoon

1 teaspoon nutmeg

Margarine

1 cup

1 cup shortening plus 1/2 teaspoon salt OR 1 cup butter OR 7/8 cup vegetable oil plus 1/2 teaspoon salt OR 7/8 cup lard plus 1/2 teaspoon salt

Mayonnaise

1 cup

1 cup sour cream OR 1 cup plain yogurt

Milk (whole)

1 cup

1 cup soy milk OR 1 cup rice milk OR 1 cup water or juice OR 1/4 cup dry milk powder plus 1 cup water OR 2/3 cup evaporated milk plus 1/3 cup water

Mint (fresh)

1/4 cup chopped

1 tablespoon dried mint leaves

Molasses

1 cup

Mix 3/4 cup brown sugar and 1 teaspoon cream of tartar

Mustard: prepared

1 tablespoon

Mix together 1 tablespoon dried mustard, 1 teaspoon water, 1 teaspoon vinegar and 1 teaspoon sugar

Onion

1 cup, chopped

1 cup chopped green onions OR 1 cup chopped shallots OR 1 cup chopped leeks OR 1/4 cup dried minced onion OR 1/4 cup onion powder

Orange juice

1 tablespoon

1 tablespoon other citrus juice

Orange zest

1 tablespoon

1/2 teaspoon orange extract OR 1 teaspoon lemon juice

Parmesan cheese

1/2 cup, grated

1/2 cup grated Asiago cheese OR 1/2 cup grated Romano cheese

Parsley

1 tablespoon chopped fresh

1 tablespoon chopped fresh chervil OR 1 teaspoon dried parsley

Pepperoni

1 ounce

1 ounce salami

Raisin

1 cup

1 cup dried currants OR 1 cup dried cranberries OR 1 cup chopped pitted prunes

Rice: white

1 cup, cooked

1 cup cooked barley OR 1 cup cooked bulgur OR 1 cup cooked brown or wild rice

Ricotta

1 cup

1 cup dry cottage cheese OR 1 cup silken tofu

Rum

1 tablespoon

1/2 teaspoon rum extract, plus enough water to make 1 tablespoon

Saffron

1/4 teaspoon

1/4 teaspoon turmeric

Salami

1 ounce

1 ounce pepperoni

Semisweet chocolate chips

1 cup

1 cup chocolate candies OR 1 cup peanut butter or other flavored chips OR 1 cup chopped nuts OR 1 cup chopped dried fruit

Shallots, chopped

1/2 cup

1/2 cup chopped onion OR 1/2 cup chopped leek OR 1/2 cup chopped green onion

Shortening

1 cup

1 cup butter OR 1 cup margarine minus 1/2 teaspoon salt from recipe

Sour cream

1 cup

1 cup plain yogurt OR 1 tablespoon lemon juice or vinegar plus enough cream to make 1 cup OR 3/4 cup buttermilk mixed with 1/3 cup butter

Sour milk

1 cup

1 tablespoon vinegar or lemon juice mixed with enough milk to make 1 cup: Let stand 5 minutes to thicken

Soy sauce

1/2 cup

1/4 cup Worcestershire sauce mixed with 1 tablespoon water

Stock: beef or chicken

1 cup

1 cube beef or chicken bouillon dissolved in 1 cup water

Sweetened condensed milk

1 (14-ounce) can

3/4 cup white sugar mixed with 1/2 cup water and 1 1/8 cups dry powdered milk: Bring to a boil and cook, stirring frequently, until thickened, about 20 minutes

Vegetable oil (for baking)

1 cup

1 cup applesauce OR 1 cup fruit puree

Vegetable oil (for frying)

1 cup

1 cup lard OR 1 cup vegetable shortening

Vinegar

1 teaspoon

1 teaspoon lemon or lime juice OR 2 teaspoons white wine

White sugar

1 cup

1 cup brown sugar OR 1 1/4 cups confectioners' sugar OR 3/4 cup honey OR 3/4 cup corn syrup

Wine

1 cup

1 cup chicken or beef broth OR 1 cup fruit juice mixed with 2 teaspoons vinegar OR 1 cup water

Yeast: active dry

1 (.25-ounce) package

1 cake compressed yeast OR 2 1/2 teaspoons active dry yeast OR 2 1/2 teaspoons rapid rise yeast

Yogurt

1 cup

1 cup sour cream OR 1 cup buttermilk OR 1 cup sour milk

 

General -- So helpful

3 teaspoons = 1 tablespoon
4 tablespooons = 1/4 cup
5 tablespoons + 1 teaspoon = 1/3 cup
16 tablespoons = 1 cup
2 cups = 1 pint
2 pints = 1 quart

Butter

½ ounce (1/8 stick) = 1 tablespoon
1 ounce (1/4 stick) = 2 tablespoons
2 ounces (1/2 stick) = 4 tablespoons
4 ounces (1 stick) = 1/2 cup
16 ounces (4 sticks) = 2 cups

Chocolate

12-ounce morsels = 1 cup melted chocolate
12-ounce morsels = 2 cups whole morsels

Cream

1 cup heavy cream = 2 cups whipped cream

Eggs

8-10 whites, large = 1 cup egg whites
12-14 yolks, large = 1 cup egg yolks

Flour

1 pound = 4 cups

Fruit

1 medium lemon = 3 tablespoons juice + 1 tablespoon grated rind
1 medium orange = 1/3 to 1/2 cup juice + 2 tablespoons grated rind
1 pound apples = 3 medium whole or 3 cups sliced
1 pound bananas = 3 medium whole or 1½ cups mashed

Nutmeats

4½ ounces nuts, chopped = 1 cup

Popcorn

¼ cup kernels = 8 cups popped

Sugar

1 pound brown sugar = 2¼ cups
1 pound confectioners’ = 4½ cups sifted

Chemical Reactions That Happen In Your Everyday Life

How to Recognize a Chemical Reaction

The first step to identify chemical reactions around you solely depends on being aware of when a reaction is taking place. Not every change in any matter makes it a chemical reaction. For example, many things may change in size or shape, like melting ice, dissolving sugar or salt in water, or treating a sheet into small pieces, these are only physical changes and do not change their chemical composition or identity. Below we have listed a few signs that tell if a chemical reaction is taking place. If there is more than one sign, it is more likely that a chemical reaction has occurred: 

Change in temperature

Change in color 

Sudden change in odor 

Bubbling or gas production

Formation of solid when liquids are mixed

Here are 10 Chemical Reactions That Take Place In Our Everyday Lives 

1. Rusting

Rusting is the process of oxidation, which is the result of a reaction that takes place because of oxygen. It gives a flaky brown layer that gathers over iron surfaces, this layer is formed due to the oxidization of the topmost layer, leading to the formation of metal oxide. It is just not with iron but these layers forms on other metals as well, like copper, silver, and gold. 

Fe + 3O₂ + xH₂O → Fe₃O₄ . xH₂O

2. Digestion

Did you know? Every time we eat something, a chemical reaction is simultaneously taking place to digest it. Digestion is also a complex process, in which thousands of chemical reactions take place. For example, when you eat something, the water and enzyme named amylase breaks down carbohydrates and sugar into simple molecules. Enzymes and hydrochloric acid, which is present in your stomach breaks down the proteins, meanwhile sodium bicarbonate is released into the small intestine for neutralizing the acid and protecting the digestive tract. The digestive system of animals works the same way. 

3. Photosynthesis

You all might already be familiar with the term photosynthesis, it is widely discussed in science textbooks under the biology section. Just like humans, several chemical reactions take place in plants as well, a chemical reaction called photosynthesis converts carbon dioxide and water into plant food – glucose, and oxygen. It is one of the major chemical reactions as it leads to the generation of oxygen and provides food for both plants and animals. 

6 CO2 + 6 H2O + light → C​6H12O6 + 6 O2

4. Detergent and Soap Reactions 

If you’re thinking that just washing your hands with water counts as a chemical reaction, then you’re probably wrong. Because you are just technically rinsing away dirt. When you apply detergent or soap, the chemical reaction is responsible for emulsifying grease and lowering surface tension, so that you can easily remove the dirt. Most reactions occur in dishwashing or laundry detergents as they contain certain enzymes that break proteins and whiteners to prevent clothes from looking dirty.  

5. Aerobic Cellular Respiration 

In this animals use oxygen, which is provided by plants for performing reverse reactions of photosynthesis so that the cells receive energy. Aerobic respiration creates a chemical reaction between oxygen and glucose to form water and chemical energy in the form of ATP, adenosine triphosphate.

C6H12O6 + 6O2 → 6CO2 + 6H2O + energy (36 ATP)

6. Anaerobic Cellular Respiration

Organisms have their ways of getting energy without oxygen. Anaerobic respiration mainly occurs without oxygen, it releases less energy than aerobic respiration. If anaerobic respiration takes place in microorganisms, it is known as fermentation. Bacteria and yeast use anaerobic respiration to make everyday products like vinegar, wine, yogurt, cheese, bread, and beer. 

C6H12O6 → 2C2H5OH + 2CO2 + energy

7. Acid-Base Reactions 

Acid-Base reactions usually occur when you mix an acid (vinegar, lemon juice, battery acid, muriatic acid, carbonic acid (from carbonated drinks) with any base like ammonia, baking soda, and lye. The best example of this is the reaction between vinegar and baking soda to form water, sodium acetate, and carbon dioxide gas. 

NaHCO3 + HC2H3O2 → NaC2H3O2 + H2O + CO2

Examples of Chemical Reactions in the Kitchen

Bread

The bread most Americans eat is leavened bread, or bread that has risen. It contains air pockets that make it fluffy or chewy. Things that make it rise, called leavening agents, include yeast, baking soda, baking powder and acids such as buttermilk. Chemical reactions occur between an acid and an alkaline--baking powder or baking soda--forming gas pockets, which make the dough rise. Yeast fungus, when combined with warm water, begins to ferment the natural sugars and carbohydrates found in flour and other bread ingredients. This fermentation process forms gas bubbles and makes the bread rise over a period of hours. Some breads, such as sourdough bread, put these ingredients together in a “starter” that ferments and is then added to the bread ingredients, which shortens the rising time.

Meringue

A variety of desserts, soufflés and other baked goods are made with meringue, which is made of whipped egg whites and either sugar or corn starch. Fresh egg whites are placed in a bowl and briskly whisked by hand or with a beater. As the air begins to infiltrate the egg whites and the heat and force of the beating begin to take effect, the whites' amino acid chains begin to uncoil in a process called denaturation. This occurs when the chemical bonds that hold the chains together are broken and is aided by the acidic nature of egg whites. After they uncoil, they begin to mesh together, or coagulate, with pockets of air trapped among them. Adding sugar when the eggs begin to foam holds the air in place, so that the bubbles do not pop and deflate the meringue. Using a copper bowl or adding an acid such as lemon juice, cream of tartar or vinegar also helps with stabilizing the air pockets.

Meat

Cooking meat, especially searing, produces the Maillard reaction, which occurs when sugars and the denatured proteins in the meat begin to break down and reconfigure. This reaction, discovered by the French scientist Louis-Camille Maillard in the early 20th century, occurs between 300 and 500 degrees Fahrenheit and is commonly referred to as browning. This adds the meaty flavors and aromas we associate with meat.

Cheese

Cheese is made of milk or cream that is mixed with rennet, an enzyme found in a cow or sheep’s stomach, and a lactic acid bacteria culture. The rennet breaks down the protein in milk, called casein, and separates it into curd and a watery substance called whey. For most cheeses, the two are separated and the curd is salted and pressed into molds. It sits in the molds and ripens as the bacteria culture continues to break down the casein in the milk until cheese is formed. Different milks, such as goat, cow or sheep, and different bacterial cultures combine to form different varieties of cheese.