using rennet to set milk. the idea is not new. yann duytsche and jordi cruz both make desserts featuring this technique. cheese makers have been setting, or should i say coagulating, milk with rennet for thousands of years. i guess it is one of those ideas that was sat on a shelf in the back in a corner of my brain, collecting dust until for some reason it came into play this week.
rennet is an enzyme that was originally found in the stomach of calves. the discovery took place when someone tried to store milk and found curds/cheese when they opened the stomach. this became the original technique for cheese making.
today rennet is made from either animal or vegetable products. pure rennet from the stomachs of mammals is available however the demand for animal rennet exceeds the number of stomachs available to supply this demand. the results have been a genetically manufactured version that is readily available.
no matter which type of rennet you use the idea behind how it works is the same. protease (animal), pepsin (vegetable) or chymosin (genetically engineered) is the enzyme that causes milk to coagulate. milk is made up of water (88%), lactose (4.5 – 5.5%), protein (3.5% in cows), fat (3.5-5%) and trace amounts of minerals and enzymes. when rennet is added to the milk it interacts with the protein (casein). a molecule of casein is covered by little hairs. casein is naturally attracted to itself but these hairs prevent the molecules from touching each other and clumping together. rennet removes a potion of these hairs thus allowing the casein to clump together. these clumps are the curds used to make cheese.
the idea that i would like to explore is using flavored curds or using casein and rennet to set other liquids, but first we need to be able to make simple curds. that was the goal this week – to use a local buffalo milk, sweeten it slightly and set it using rennet.
the first test was with normal milk, sugar and vanilla bean. a small amount of acid was added to help in the curdling process (as i do more research i am not sure that this was necessary). a few drops of rennet and the milk curdled in about 20 minutes. this made very delicate curds that when cut to make a portion bled out their whey immediately. this was one of those duhhh moments. when making cheese, once the curd is set they are cut…. to drain the whey. due to the very delicate nature of the curd any trauma will cause the whey to bleed out and i don’t want bleeding curds. the solutions was to make individual portions. i did not get the product i wanted but i did try another experiment – to process the curd similar to cheese.






test 2 – buffalo milk, sugar, acid and rennet. this batch went a lot better except it set a lot faster and there was not enough time to put the milk into the moulds before it set so on to test 2.1- add the rennet to the individual mould then pour the milk on top. perfect. nice, simple cubes of sweet buffalo milk curds.
- sweet buffalo milk curds
- cherry meringue
- almond crumble
- apricot sorbet



buffalo milk curds
750g buffalo milk
100g sugar
.2g powder rennet
.2g citric acid
8g water
- dissolve rennet and acid in water
- place five drops of rennet in each mould
- heat milk and sugar to 37C and pour on top of rennet
- leave to set for 20min – 1 h