Chef at 17:10, 15 August 2014

2014-08-15T17:10:36Z

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{{#seo:
|title=Rennet: Cooking Wiki
|titlemode=replace
|keywords=#cheese #whey #cheeses #goat #cheesemaking #vinegar #wine #sheepsmilk #curds #storecupboarditems #veal
|hashtagrev=12032020
|description=Rennet is an enzyme-containing substance produced in any mammalian stomach to digest the mother's milk, and is often used in the production
}}


[[Image:Rennet.jpg|thumb|right|300px|thumb|right|300px|Animal rennet]]
'''Rennet''' is an enzyme-containing substance produced in any mammalian stomach to digest the mother's [[milk]], and is often used in the production of [[cheese]]. Rennet contains many enzymes, including a proteolytic enzyme (protease) that coagulates or sets the milk, causing it to separate into solids ([[curds]]) and liquid ([[whey]]). The active enzyme in rennet is called chymosin or rennin (EC 3.4.23.4) but there are also other important enzymes in it, e.g., pepsin or lipase. There are non-animal sources for rennet substitutes.
===Production of natural calf rennet===

Natural calf rennet is extracted from the inner mucosa of the fourth stomach chamber (the abomasum) of young calves. These stomachs are a by product of [[veal]] production. If rennet is extracted from older calves (grass-fed or grain-fed), the rennet contains less or no chymosin but a high level of pepsin and can only be used for special types of [[milk]] and [[cheeses]]. As each ruminant produces a special kind of rennet to digest the [[milk]] of its own mother, there are milk-specific rennets available, such as kid [[goat]] rennet especially for [[goats' milk]] and [[lamb]] rennet for [[sheep's milk]]. Rennet or digestion enzymes from other animals, such as swine-pepsin, are not used in cheese production.

===Traditional method===

Dried and cleaned stomachs of young calves are sliced into small pieces and then put into saltwater or [[whey]], together with some [[vinegar]] or [[wine]] to lower the pH of the solution. After some time (overnight or several days), the solution is filtered. The crude rennet that remains in the filtered solution can then be used to coagulate milk. About 1 gram of this solution can normally coagulate 2000 to 4000 grams of milk.

Today this method is used only by traditional cheese-makers in central Europe: Switzerland, Jura, France, Romania, and Alp-Sennereien in Austria.

===Modern method===

Deep-frozen stomachs are milled and put into an enzyme-extracting solution. The crude rennet extract is then activated by adding acid; the enzymes in the stomach are produced in an inactive preform and are activated by the stomach acid. After neutralisation of the acid, the rennet extract is filtered in several stages and concentrated until reaching the required potency, usually about 1:15000 (meaning 1 kg of rennet would have the ability to coagulate 15000 litres of milk).

In 1 kg of rennet extract, there are about 0.7 grams of active enzymes – the rest is water and [[salt]] and sometimes sodium benzoate, E211, at a concentration of 0.5-1% as a preservative. Typically, 1 kg of cheese contains about 0.0003 grams of rennet enzymes.

==Using rennet==
This is only a rough guide as many factors such as milk-type, temperature and cheese recipe affect the setting ability of rennet.

'''Directions for animal and vegetarian rennet are identical.'''
===Liquid rennet===
Only a very small amount is required. About 2 drops per litre of [[milk]] for a hard [[cheese]] and 1 drop per litre for a soft [[cheese]]. Add the drops of rennet to a little cold pre-boiled water, mix well and whisk into the milk as directed by your recipe.

===Powdered rennet===
25 grams of powdered rennet will make 300 ml of liquid rennet and thus needs to be rehydrated before use. To do this, dissolve the powder in a 20% brine solution (60 grams salt in 250 ml cold pre-boiled water).

Use within 3 months once re hydrated.

Milk will curdle at 2 degrees higher when powdered rennet is used.

{{CategoryLineIngredients}}
[[Category:Ingredients]]
[[Category:Meat]]
[[Category:Store cupboard items]]
[[Category:Cheese making]]

<code 'hashtagrev:12032020'>[[Special:Search/cheese|#cheese]] [[Special:Search/whey|#whey]] [[Special:Search/cheeses|#cheeses]] [[Special:Search/goat|#goat]] [[Special:Search/cheesemaking|#cheesemaking]] [[Special:Search/vinegar|#vinegar]] [[Special:Search/wine|#wine]] [[Special:Search/sheepsmilk|#sheepsmilk]] [[Special:Search/curds|#curds]] [[Special:Search/storecupboarditems|#storecupboarditems]] [[Special:Search/veal|#veal]]
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Rennet - Revision history

Chef at 17:10, 15 August 2014