How to Render Duck Fat


To render fat is basically to melt the fat into a liquid form. 
rendered duck fat
You make duck fat slowly by simmering the fat covered with water (left), or by directly rendering the fat in a skillet placed over a medium flame. Read about the two methods below. 

How to Make Duck Fat


Duck fat contains 35.7% saturates, 50.5% monounsaturates (high in linoleic acid) and 13.7% polyunsaturated fats.(which contains Omega-6 and Omega-3 essential oils). This compares to olive oil which is: 75% monounsaturated fat (mostly oleic acid) 13% saturated fat and 10% Omega-6 linoleic acid and 2% Omega-3 linoleic acid. The main difference between chicken, turkey and duck is that duck contains more linoleic acid, which chicken and turkey contain a higher amount of polyunsaturated fats --- Read more about Health Benefits of Duck Fat

A comparison of the two methods for How to Make Duck Fat

Remove the fat from the duck.    Remove the fat from the duck. 
Chop the fat into very small pieces    Chop the fat into very small pieces 
Add the fat to a frying pan and spread out to cover    Add the fat to a frying pan and spread out to cover 
Cover the fat with water   Cook on a low flame allowing the fat to melt
Cook on a medium flame allowing the fat to render into the water   As fat renders spoon off into a bowl
Continue to cook until the water has evaporated and only a slight simmer is visible   Continue cooking till most of the fat has been rendered 
Filter off the duck fat reserving the remain fat for cracklings   Filter off the duck fat reserving the remain fat for cracklings
Store overnight in the refrigerator   Store overnight in the refrigerator


The two methods were compared: 300 grams of diced fat were added to two separate frying pans.

water rendered duck fat   The duck fat is covered with water.
rendering duck fat   The duck fat is rendered directly from the pan...removing the liquid as it becomes available. 
duck fat rendered in water   The fat is slowly rendered into the water. Any discoloration is prevented since the temperature remains near 212F
rendering duck fat   The remaining amount of fat is stored separately or discarded if it appears too oxidized.
rendered duck oil  

The collected unfiltered oil is clear... there is no presence of water. 

rendered duck fat  

The collected oil is slightly cloudy, possibly a result of retaining water


Both methods provide for cracklings
duck cracklings
Cracklings can be stored in the freezer. It is best to still have fat left in them. Then, simply take them from the freezer right into the pan for the final crisp.
After refrigeration the duck fat that is rendered using Method II has a softer consistency most likely a result of the presence of water. (See below) 

To see if the cloudiness during preparation and the softer texture of the fat was due to water retention we calculated the density for both fats preparations.


This value is consistent with most fats and oils.



This value indicates the presence of water. 

Note: the density of butter can vary between 0.911 and 0.95 depending on amount of water.

Pros and Cons for each method -- How to make Duck Fat-- 

Method I provides for a clearer more pure form of duck fat. Method II retains water which can decrease shelf-life. In addition Method II requires constant watching during the rendering process. However for small amounts of duck fat Method II is preferred. 

Note: Duck fat which may contains water should not be added to a very hot pan since the fat may splatter. Add to a low heat pot and allow the sizzle to die down first.

See also a YouTube Video on rendering fat using Method II---- You Tube video on how to render fat

Characterizing Quality of Rendered Duck Fat