Learn the science behind:
There are a lot of different creams out these in the supermarket nowadays. An acidic sour cream to top a baked potato, a heavy whipping cream to top your apple pie and so many more. Clotted cream is yet another one and is the thickest and creamiest of them all. It’s not as common as the others, expect for the UK, where you can easily find it in most supermarkets as it is a core component of any afternoon tea with scones & jam.
Clotted cream is so thick and creamy, that it behaves in its own unique way. So why does it behave so special? Time for some clotted cream science, best read with a scone close by.
What is clotted cream?
Clotted cream is a type of cream, made from cow’s milk with a very high fat content, up to 55%. This is a very high. Most other creams won’t go over 38% fat. For comparison, the other high fat content creams are 30% for creme fraiche and whipping cream contains about 35% fat. It really is a concentrated version of cream.
Because of its very high fat content clotted cream doesn’t flow freely. Instead, it has a smooth thick texture. It is softer than butter though, since it does contain less fat.
Cream itself is mostly water + fat (butterfat). Butterfat is solid in the fridge and semi-solid at room temperature (use the consistency of butter as a reference). There will be some protein, but since this all resides within the moisture, the protein content does down if fat content goes up. The way to increase fat content is to decrease the water content.
What does clotted cream taste like?
Most of the flavour of clotted cream comes from the butterfat, literally the fat that butter is made of. Butterfat contains several flavour molecules, but is otherwise quite neutral in flavour. Clotted cream is quite neutral in flavour as well.
Clotted cream is not sweet. It is the same as unwhipped cream. Both are neutral in flavour and need sugar to be sweetened. It’s also why clotted cream is such a great complement to scones and jam. Jam provides sweetness, scones provide a structure and chew and the clotted cream gives the richness. A well balanced dish.
Oil in water emulsion
Clotted cream is an oil-in-water emulsion. Fat and water don’t mix, instead, the molecules just float around one another and will have a tendency to separate again. Water and fat form an emulsion. One of the two phases will be the continuous phase whereas the other one will float within that one. In the case of creams, the continuous phase is water with fat molecules floating in them.
Butter is also closely related to cream. Butter is made from an even more concentrated form of cream and contains more than 80% fat. The most important different though is that butter has converted into a water-in-fat emulsion. Fat has become the continuous phase instead of the water.
How clotted cream is made
In order to make clotted cream from milk you have to get rid of a lot of moisture. The whole process for make clotted cream is focused on that. A common way to get rid of moisture is to boil it off. However, for clotted cream you don’t want to do so since it will also affect the overall behaviour of the cream. Instead, you use the concept of sedimentation to split the water from the cream.
The fat particles in milk have a lower density than water. If that happens, the phase with the lowest density will float to the top whereas the heavier phase will sink to the bottom. If you wait long enough, the fat and water will separate to a great extent by itself. However, you don’t want to wait too long.
You start the manufacturing process by separating ‘regular’ cream from milk through sedimentation or centrifugation. To then separate even more fat you heat up the cream. By heating up the cream you denature some of the whey proteins and destabilize the fat bubbles, helping it to float to the top of the mass. You want to cool this down relatively slowly, for all the fat to float up to the top and form a ‘crust’. Remove this ‘crust’ and you’ve got your clotted cream.
Making clotted cream the ‘right’ way is quite a bit of an exercise. It is made by gently heating regular cream at 40°C for up to 12 hours. During this heating process the fat in the cream will rise to the top. This has to be scooped off and will be your clotted cream.
Imitation clotted cream
Since it’s quite a trouble to make clotted cream (especially if you don’t have a low temperature oven), and since it tends to be less widely available, several imitation recipes float around the web. Some involve mixing creme fraiche with mascarpone, two other rich dairy products. These products look and kind of taste like clotted cream. It’s a very simple and smart solution, with more regularly available ingredients, but interesting because both of the ingredients have undergone very different processing steps than clotted cream!
Besides the fact that I’ve eaten clotted cream, I haven’t yet tried making it myself. So I had to really on the worldwide web to gain some knowledge. Here are some of the sources I’ve been using: the Kitchn, wikipedia, Tori Avey, and a manufacturer’s website.
Kelly’s of Cornwall, How do you make clotted cream?, link
Carl A. Batt, Encyclopedia of food microbiology, 2014, p.730, link