Degreasing, often called defatting or fat trimming, is the removal of fatty acids from an object. In
culinary
Culinary arts are the cuisine arts of food preparation, cooking, and presentation of food, usually in the form of meals. People working in this field – especially in establishments such as restaurants – are commonly called chefs or ...
science, degreasing is done with the intention of reducing the
fat
In nutrition science, nutrition, biology, and chemistry, fat usually means any ester of fatty acids, or a mixture of such chemical compound, compounds, most commonly those that occur in living beings or in food.
The term often refers specif ...
content of a
meal
A meal is an occasion that takes place at a certain time and includes consumption of food. The English names used for specific meals vary, depending on the speaker's culture, the time of day, or the size of the meal. A meal is different from a ...
.
Degreasing food
Degreasing is often used by
dieters, particularly those following low-fat diets to reduce their fat consumption to induce weight loss. The energy content of 1 g of fat is 9
calories
The calorie is a unit of energy that originated from the caloric theory of heat. The large calorie, food calorie, dietary calorie, kilocalorie, or kilogram calorie is defined as the amount of heat needed to raise the temperature of one liter o ...
, while that of
carbohydrates
A carbohydrate () is a biomolecule composed of carbon (C), hydrogen (H), and oxygen (O) atoms. The typical hydrogen-to-oxygen atomic ratio is 2:1, analogous to that of water, and is represented by the empirical formula (where ''m'' and ''n'' ma ...
and
proteins
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, re ...
are 4 calories. Hence, dieters often view decreasing fat consumption as an efficient way of losing weight without greatly sacrificing total volume of food. Degreasing during meal preparation is used to reduce the energy content of the food being prepared.
Those people who wish to reduce their cholesterol level or fat intake, in particular people with
hypercholesterolemia
Hypercholesterolemia, also called high cholesterol, is the presence of high levels of cholesterol in the blood. It is a form of hyperlipidemia (high levels of lipids in the blood), hyperlipoproteinemia (high levels of lipoproteins in the blood), ...
often use degreasing to reduce their fat consumption.
Degreasing of a meal during preparation
Fat trimming of a meal can be done during preparation by a variety of methods. The most common methods involving substituting food items or removal of naturally occurring fat and conservative addition of fat.
Substituting fats is a method in which a certain ingredient is substituted by another ingredient. A common way of doing this is substituting saturated
fatty acids
In chemistry, in particular in biochemistry, a fatty acid is a carboxylic acid with an aliphatic chain, which is either saturated or unsaturated. Most naturally occurring fatty acids have an unbranched chain of an even number of carbon atoms, ...
with unsaturated fatty acids while cooking. For instance, olive oil can be used instead of butter for seasoning vegetables.
Food items are also substituted to reduce fat content. For instance, instead of using eggs by using a whole egg, where the egg yolks are high in fat levels, egg whites can instead be used. Alternatively,
skimmed milk
Skimmed milk (British English), or skim milk (American English), is made when all the milkfat is removed from whole milk. It tends to contain around 0.1% to 0.3% fat.
Background
Historically, skimmed milk was used for fattening pigs, and was re ...
or similar low-fat products can be used as ingredients for
cooking
Cooking, also known as cookery or professionally as the culinary arts, is the art, science and craft of using heat to make food more palatable, digestible, nutritious, or Food safety, safe. Cooking techniques and ingredients vary widely, from ...
.
Degreasing liquids

Many different foods can be degreased after preparation. Liquid foods that are high in fat, such as
braising
Braising (from the French language, French word ''braiser'') is a combination-cooking method that uses both wet and dry heats: typically, the food is first Browning (cooking), browned at a high temperature, then simmered in a covered pot in cook ...
liquids,
roasting
Roasting is a cooking method that uses dry heat where hot air covers the food, cooking it evenly on all sides with temperatures of at least from an open flame, oven, or other heat source. Roasting can enhance the flavor through caramelizat ...
juices and
broth
Broth, also known as bouillon (), is a savory liquid made of water in which meat, fish, or vegetables have been simmered for a short period of time. It can be eaten alone, but it is most commonly used to prepare other dishes, such as soups ...
s may have floating oil on top throughout and after the cooking process. Fat can be skimmed off the liquid with a small
ladle, spoon, or cup as the liquid
simmers and then discarded. This is done by placing the saucepan with only half of it on the heat source so that the liquid simmers only on one side. This pushes the fat to the opposite side and makes it easier to lift off with the ladle. The fat can then be skimmed off by holding the ladle so that the top of its bowl is almost level with the liquid and then tilting it slightly and in a circular motion toward the edge of the saucepan where the fat accumulates.
As braising liquids and broths simmer, they typically throw off more fat and protein and sometimes froth, so it is easier to wait at least a few minutes until the liquid has cooled before degreasing. In making slowly reduced liquids it may be ideal to wait for it to cool even longer.
As an alternative to a ladle, a
degreasing cup can be used to skim the fat off hot liquids. This is a clear plastic or glass cup that looks similar to a
teapot
A teapot is a vessel used for steeping tea leaves or a herbal mix in boiling or near-boiling water and serving the resulting infusion called tea; usually put in a teacup. It is one of the core components of teaware.
Teapots usually have an ...
, with a spout that comes out of the bottom. The liquid and juices are poured into the cup then poured out leaving the fat behind; the liquid comes from the bottom of the cup instead of the top. Degreasing cups come in various sizes.
Refrigerating or freezing liquids until the fat congeals and solidifies can make the fat easier to remove with a spoon. If, after removing the congealed fat, the liquid still appears cloudy, it can be made clearer by skimming it again with a ladle after bringing it to a gentle simmer to allow for the release of more fat and insoluble proteins.
Degreasing solid food items
Some items, such as roasted foods, and other cooked food items, such as pizza, can sometimes be oily and greasy. Degreasing them after preparation may provide a solution to this problem. Fried foods, such as
French fries
French fries, or simply fries, also known as chips, and finger chips (Indian English), are '' batonnet'' or '' julienne''-cut deep-fried potatoes of disputed origin. They are prepared by cutting potatoes into even strips, drying them, and f ...
, can often be degreased without decreasing the crispiness of the food item by simply blotting out the oil in the food item with a
tissue paper
Tissue paper, or simply tissue, is a lightweight paper or light crêpe paper. Tissue can be made from recycled pulp (paper), paper pulp on a paper machine.
Tissue paper is very versatile, and different kinds are made to best serve these purposes ...
.
Commercial degreasing
Many food manufacturing companies such as
Weight Watchers have been developed for people who wish to reduce their fat intake. The customer need of defatting has also led to the production of low fat products, e.g., low fat cheese.
Degreasing in the tanning industry
Degreasing may also refer to the removal of excess fat and grease lodged within the fur pelts of
bears
Bears are carnivoran mammals of the family Ursidae (). They are classified as caniforms, or doglike carnivorans. Although only eight species of bears are extant, they are widespread, appearing in a wide variety of habitats throughout most o ...
,
raccoons
The raccoon ( or , ''Procyon lotor''), sometimes called the North American, northern or common raccoon (also spelled racoon) to distinguish it from Procyonina, other species of raccoon, is a mammal native to North America. It is the largest ...
,
beavers
Beavers (genus ''Castor'') are large, semiaquatic rodents of the Northern Hemisphere. There are two existing species: the North American beaver (''Castor canadensis'') and the Eurasian beaver (''C. fiber''). Beavers are the second-large ...
,
possums
Possum may refer to:
Animals
* Didelphimorphia, or (o)possums, an order of marsupials native to the Americas
** Didelphis, a genus of marsupials within Didelphimorphia
*** Common opossum, native to Central and South America
*** Virginia opossum, ...
and
wolverines. In modern-day tanning operations, the removal of this grease is achieved by adding a liquid chemical agent, usually 2
fluid ounces
A fluid ounce (abbreviated fl oz, fl. oz. or oz. fl., old forms ℥, fl ℥, f℥, ƒ ℥) is a unit of volume (also called ''capacity'') typically used for measuring liquids. The British Imperial, the United States customary, and the United S ...
(60
milliliters) to every 5
gallons
The gallon is a unit of volume in British imperial units and United States customary units.
The imperial gallon (imp gal) is defined as , and is or was used in the United Kingdom and its former colonies, including Ireland, Canada, Australia, ...
(19
litres
The litre ( Commonwealth spelling) or liter (American spelling) (SI symbols L and l, other symbol used: ℓ) is a metric unit of volume. It is equal to 1 cubic decimetre (dm3), 1000 cubic centimetres (cm3) or 0.001 cubic metres (m3). A cubic ...
) of pickling solution. The chemical agent is sometimes known as a "relaxer," and where the hides are left to soak for 3 to 4 days. Detergent degreasing has also been used extensively in the tanning industry, but which has often had environmental impacts. In
Turkey
Turkey, officially the Republic of Türkiye, is a country mainly located in Anatolia in West Asia, with a relatively small part called East Thrace in Southeast Europe. It borders the Black Sea to the north; Georgia (country), Georgia, Armen ...
, degreasing of sheepskin with the wool intact is performed on hides after stretching the leather, when they are then inserted inside a large, revolving drum with
beechwood sawdust and
nepheline
Nepheline, also called nephelite (), is a rock-forming mineral in the feldspathoid groupa silica-undersaturated aluminosilicate, Na3 K Al4 Si4 O16, that occurs in intrusive and volcanic rocks with low silica, and in their associated pegmatit ...
powder, for about 6 hours. Afterwards, the hides are dusted from the sawdust residue and stretched again.
Another simple method is to rub hot
cornmeal
Maize meal is a meal (coarse flour) ground from dried maize. It is a common staple food and is ground to coarse, medium, and fine consistencies, but it is not as fine as wheat flour can be.Herbst, Sharon, ''Food Lover's Companion'', Third Editi ...
or
sawdust
Sawdust (or wood dust) is a by-product or waste product of woodworking operations such as sawing, sanding, milling and routing. It is composed of very small chips of wood. These operations can be performed by woodworking machinery, portable p ...
over the flesh-side of the animal pelt, followed by scraping. In modern tanning methods, the process of degreasing is usually performed after
bating and drenching, and is then followed by pickling and tanning.
Solvent degreasing
Solvent degreasing is a process used to prepare a part for further operations such as
electroplating
Electroplating, also known as electrochemical deposition or electrodeposition, is a process for producing a metal coating on a solid substrate through the redox, reduction of cations of that metal by means of a direct current, direct electric cur ...
or
paint
Paint is a material or mixture that, when applied to a solid material and allowed to dry, adds a film-like layer. As art, this is used to create an image or images known as a painting. Paint can be made in many colors and types. Most paints are ...
ing. Typically it uses
petroleum
Petroleum, also known as crude oil or simply oil, is a naturally occurring, yellowish-black liquid chemical mixture found in geological formations, consisting mainly of hydrocarbons. The term ''petroleum'' refers both to naturally occurring un ...
,
chlorine
Chlorine is a chemical element; it has Symbol (chemistry), symbol Cl and atomic number 17. The second-lightest of the halogens, it appears between fluorine and bromine in the periodic table and its properties are mostly intermediate between ...
, or
alcohol
Alcohol may refer to:
Common uses
* Alcohol (chemistry), a class of compounds
* Ethanol, one of several alcohols, commonly known as alcohol in everyday life
** Alcohol (drug), intoxicant found in alcoholic beverages
** Alcoholic beverage, an alco ...
based
solvent
A solvent (from the Latin language, Latin ''wikt:solvo#Latin, solvō'', "loosen, untie, solve") is a substance that dissolves a solute, resulting in a Solution (chemistry), solution. A solvent is usually a liquid but can also be a solid, a gas ...
s to dissolve the
machining
Machining is a manufacturing process where a desired shape or part is created using the controlled removal of material, most often metal, from a larger piece of raw material by cutting. Machining is a form of subtractive manufacturing, which util ...
fluids and other contaminants that might be on the part.
[Kalpakjian, Serope, Schmid, Steven R. (2006). Manufacturing Engineering and Technology. 5th ed. Upper Saddle River, NJ: Pearson Prentice Hall. 1079.]
References
{{reflist
External links
How Cholesterol WorksCook For Lower Cholesterol
Cooking techniques
Nutrition