Fats: Let's Clear the Air

Duck Fat

There is a lot of confusion on the subject of fats. These highly contested chemical compounds are sworn by some, and sworn off by others. There is much mystique surrounding fats and oils that I wish to help clarify. Those who say fats are beneficial and those who say fats are harmful are both right to a certain degree. What is important to consider is fats, meats, vegetables, and even water should all be consumed in moderation in balance of a healthy diet.

Fats and oils are members of a chemical family of organic compound molecules called lipids, some of the other members in the lipid family include waxes like beeswax and steroids like estrogen and testosterone. Lipids bodily functions are designed to store energy and provide structure to cell membranes. However, in the culinary world lipids like fats and oils provide flavor, smoothness, succulence, and tenderize foods by weakening various protein structures(McGee), for example butter weakens the gluten network in a pie dough allowing for a light and flaky crust. 

In cooking, natural fats which are the stores of fatty tissue either marbled throughout muscle or found on the outer layers of muscle provide much of the flavor to the meat. Fats absorb many of the aromatic compounds in an animal's diet, these compounds remain in the fat until the fat is consumed at the dining table(Goldwyn).

Fats also often lend themselves to the tenderness and succulence of tough cuts of meat cooked over long periods of low heat. The fatty tissue in tough meat is not the same as pure rendered fat. This fatty tissue also contains collagen and other proteins that make the fatty tissue tough to consume, if uncooked (Myhrvold, 3: 83). When fat and collagen are broken down after a long period of low heat cooking, the results are tender and moist meat.

As mentioned earlier, aromatic chemical compounds can be infused in lipids such as the fat taking on the flavor of an animals diet, this is known as solubility. Lipids solubility allows for some interesting culinary applications. For example, one can infuse desired flavors into any fat of choice. I combined chili's and garlic in olive oil in a previous post.

Another interesting property of fats and oils are they do not naturally mix with water. You may have seen a vinaigrette that had a separated oil floating on top of the vinegar. A quick fix to this is shaking the bottle until the oil and vinegar combine into one fluid dressing. This is an example of a weak emulsification. Emulsification is the process of combining lipids and water into one mixture by breaking the oil into tiny particles which stick to an emulsifier such as egg yolk, mustard, and black pepper creating a fluid mixture of liquid and lipid. Emulsification's are valued in the kitchen to thicken and smoothen sauces, dressings, and marinades.

Cooking lipids also acts as a medium for energy transfer, lipids can achieve higher temperatures, more or less around 205C/400F as opposed to waters 100C/212F. Therefore, cooking with lipids allows for chemical reactions within food that are otherwise unachievable in cooking with steam or water. For instance, you can not drop a chicken breast in a pot of boiling water and expect a golden brown skin which is achieved via chemical reactions at temperatures higher than 212F.

These properties of fats and oils are interesting, but I have not even touched on the most common questions about culinary fats. What is a Saturated fat? Unsaturated fat? and Trans fat? Well, these different types of fats are categorized by their fatty acid carbon chain.

A saturated fat is a fat molecule whose carbon chain is saturated or filled to capacity with hydrogen atoms which means there are no double bonds between carbon atoms, essentially this a more solid fat, animal fats like tallow, lard, or butter, which are physically hardened are saturated fats(McGee). Excess usage of saturated fats are also known to raise blood cholesterol levels and raise the risk of type 2 diabetes (Mayo Clinic). However, recent studies have shown that scientists have been unfairly grouping Saturated fats together for too long, based on the carbon chain, some saturated fats raise the beneficial cholesterol in the blood(Feinman) like unrefined coconut oil.

Unsaturated fats have room for a hydrogen bond in the fatty acid chain, therefore they remain physically more fluid like olive oil. Unsaturated fats are subcategorized as monounsaturated fats, polyunsaturated fats, and Omega-3 fatty acids. Studies generally show unsaturated fats are beneficial to maintaining a healthy blood cholesterol level and lowering bad cholesterol when consumed in moderation (AHA). Omega-3 fatty acids are found primarily fatty fish like salmon, trout, and tuna, they are good for preventing heart disease and lowering blood pressure. Omega-3 Fatty acids can also be found in lesser amounts in flax seed, walnuts, and sunflower seeds (Mayo Clinic).

Trans fats are a primary issue in regards to health. Trans fats are found everywhere in processed foods from store bought bread to potato chips. These fats have a longer shelf-life than other fats or oils and can also be used without replacement as frying oil longer than other fats (Mayo Clinic). For financial reasons trans fats have become an industrial favorite in processed foods. An improved shelf life for products means a reduction of food spoilage and waste, therefore more money is gained for everyone selling the product. The financial reasoning for using trans fats are great but unfortunately they wreak havoc on our cardiovascular system.

Trans fats clog the arteries with bad cholesterol while lowering the bodies good cholesterol. Small amounts of trans fats are found throughout various food sources naturally. However, industrial processing and the refining of oils take unsaturated lipids take place on a massive scale by adding extra hydrogen atoms to unsaturated oils in large factories. This processing makes unsaturated fats have similar physical properties to saturated fats by making the processed oils have a physical firmness such as lard or beef tallow. Margarine is a perfect example of a trans fat, this spread has a physically solid consistency like butter, yet prior to industrial processing it was composed of unsaturated fat like soybean oil.  One can avoid trans fats by knowing what to look for. Trans fats are easily identifiable on ingredient lists by being labeled as partially hydrogenated oils. 

Personally, I try to avoid processed and refined foods as often as possible. Quality and convenience rarely go hand in hand in our modern food industry. Due to this, I nearly always choose quality when the option is presented. Below I have listed my most commonly used culinary lipids, all are saturated or unsaturated fats. Doctors and myself recommend avoiding personal use of trans fat as much as possible. Also, always consider the smoking point of fats before usage. When fats are brought to their smoking point, the fat starts to decompose and can even create carcinogens.  So my final words of wisdom are observe the oil's smoking point, try to purchase unrefined and/or organic oils, and avoid trans fats.

Please leave any additional questions or comments regarding fats in the comment section. Check Eating Rules Lipid Chart for healthy cooking lipid options

Pantry Fats and Oils

Extra Virgin Olive Oil
My Applications: Salad dressing, Marinades, Sauces, Dipping, Finishing Drizzle, Mixing into Pasta
Smoking Point: 410F/210C (Myhrvold, 2: 126)
Personal Thoughts: A great Extra Virgin Olive Oil should be a staple in every cook's pantry. The flavor of this oil is unique and imparts a distinct flavor that is heavily used in Mediterranean cuisine; Spain, Italy, and Greece cuisine particularly come to mind. I think the use of a good Extra Virgin Olive Oil really shines when lightly marinading seafood or enhancing a fresh pasta dish. One important note about Extra Virgin Olive Oil, is that the oil should be made without factory refinement, it is simply the pure oil from crushed olives. Be wary about where you purchase Extra Virgin Olive Oil from, many Extra Virgin Olive Oil's do not meet the specifications determined by governing agencies, and they may even include factory refinement. Also, foreign producers are known to purchase olives from African countries with less desirable olive growing conditions, they process them in Italy or Greece, then market the product as an Italian or Greek Extra Virgin Olive Oil. It is also worth noting Virgin Olive Oil, Non-Virgin Olive Oil, and Pomace Olive Oil all start with olives or olive by-products, yet receive a various amount of industrial refinement.

Canola Oil

My Applications: Marinade, Grill, Sauteing, Frying, Smoke
Smoking Point: 400-465F/205-240C (Myhrvold, 2: 126)
Personal Thoughts: Canola is my workhorse oil. This oil has a high smoking point, relatively indistinct flavor. I use this oil almost exclusively as my deep frying oil because of the aforementioned reasons. Besides it's frying applications, I often use Canola oil to help create a bark while smoking meat or saturate the surface of a steak when grilling. I would suggest buying an organic Canola oil over conventional due to the risk of pesticides used in the conventional canola product.

Peanut Oil
My Applications: Saute, Frying, Stir-Fry, Sauce
Smoking Point: 445F/230C (Myhrvold, 2: 126)
Personal Thoughts: Warning Peanut Oil may prove deadly to those with peanut allergies. However, this oil may prove delicious to everyone else. I think peanut oil is irresistible, and its distinct flavor can really enhance a dish. Due to it's high heat capabilities I generally use this oil in stir-fry's at home for it lends itself to adding depth to Chinese dishes. Any meat or vegetable I have tried cooking with this oil has only been enhanced.

Avocado Oil
My Applications: High Heat Cooking, Saute, Broiling
Smoking Point: 480-520F/249-271C(Wong, Jackman, and Wolf)
Personal Thoughts: Avocado Oil is somewhat of an odd oil, It has an abnormally high smoking point and is considered one of the healthiest cooking oils available. The oil was first developed solely for cosmetic purposes, but it has found its way onto supermarket shelves. I find that it works just fine when pan-frying or sauteing various vegetables or a chicken breast.

Sesame Oil
My Applications: Finishing Drizzle, Sauces
Smoking Point: 410-420F/210-215C (Myhrvold, 2: 126)
Personal Thoughts: This is a very strong tasting oil with a very specific usage. I use this almost entirely in an unheated form for Chinese, Japanese, and Korean cuisine. This is an Asian staple and a very subtle drizzle at the end of a stir fry, or a few droplets whisked into a Japanese dipping sauce adds a specific depth and savory taste.

Butter

My Applications: Baking, Light Saute, Compound Butter, or with Bread.
Smoking Point: 350F/175C
Personal Thoughts: Butter is a pretty poor cooking lipid. However, once clarified (separating the butterfat and milk solids) also known as Indian ghee, it achieves a far higher smoking point at 450F/230C. I still use solid butter with onions and garlic whenever I cook a hearty stew, or to add richness to a French dish. There is something comforting about butter's taste which is indispensable to me. Butter is also always used in my baking/pastry making.

Lard(Pig Fat)
My Applications: Light Saute, Sausage Making
Smoking Point: 365-400F/185-205C (Myhrvold: 2: 126)
Personal Thoughts: Lard and rendered bacon fat is a fairly uncommon treat in my home, but every ounce of the rendered fat is enjoyed. I often use lard when cooking a classic breakfast of eggs, toast, and sausage. Also, lard enhances Mexican dishes so this is definitely the fat of choice on taco night. Lard is also an essential fat and flavor when making sausages, typically lard is fairly inexpensive and can stay good in the refrigerator for about 1 year.

Duck Fat
My Applications: Roasting, Light Saute, Baking
Smoking Point: 375F/190C (Myhrvold 2: 126)
Personal Thoughts: In my opinion, this is the holy grail of all fats. I just can't get enough of duck fat. I would not suggest eating any one fat in large amounts, but used sparingly duck fat can be magical. Whether tossing brussel sprouts in duck fat, salt, and pepper, and giving a nice roast, or browning onions with this fat, the taste is extraordinarily rich yet distinct. Duck fat can either be purchased at specialty stores for a high price, or rendered at home from a purchased duck. I always acquire my duck fat by the latter option.

Citations and Further Readings:

• Achitoff-Gray, Niki. "Cooking Fats 101: What's a Smoke Point and Why Does it Matter?." Serious Eats. Serious Eats, n.d. Web. <http://www.seriouseats.com/2014/05/cooking-fats-101-whats-a-smoke-point-and-why-does-it-matter.html>. 
• "Dietary fats: Know which types to choose." Mayo Clinic. Mayo Clinic, n.d. Web. <http://www.mayoclinic.org/healthy-living/nutrition-and-healthy-eating/in-depth/fat/art-20045550 >. 
• Goldwyn, Meathead. "Basic Meat Science For Cooks." Amazingribs.com. Web. <http://amazingribs.com/tips_and_technique/meat_science.html >.
• McGee, Harold. On Food and Cooking. New York: Scriner, 2004. 797. Print. 
• "Monounsaturated Fats." American Heart Association. AHA, n.d. Web. <http://www.heart.org/HEARTORG/GettingHealthy/NutritionCenter/HealthyEating/Monounsaturated-Fats_UCM_301460_Article.jsp>.
• Myhrvold, Nathan. Modernist cuisine. Taschen, 2011. 2: 216, 3: 83. Print.
• "Saturated Fat and Health: Recent Advances in Research." US National Library of Medicine National Institutes of Health . Ed. Richard D. Feinman. PMC, n.d. Web. <http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2974200/>.
• Wong, Marie, Cecilia Requejo-Jackman, and Allan Jackman. "What is unrefined, extra virgin cold-pressed avocado oil? ." AOCS: Your Global Fats and Oils Connection. AOCS, n.d. Web. <http://www.aocs.org/Membership/FreeCover.cfm?itemnumber=1099>.