Milk - What Should a Barista Know About It?
Milk is so untrendy at the moment that I bet it becomes soon trendy again! In this blog I will open up the facts & figures about milk, how this basic ingredient of baristas is processed and what is the composition of milk.
If you are a passionate for vegan milk drink options, you can move directly to Jori’s blog about them. Otherwise take a walk through a cowshed with us!
Where is milk consumed?
It is commonly said that we Finns drink a lot of milk. True that, we consume it a lot but we are not alone. Dairy products and milk are a fundamental part of many countries’ culinary culture.
Did you know that in Japan, Malaysia and Thailand as well as in Argentina, Mexico and Iran milk is an essential part of children’s daily diet? In Southern Europe people use a lot of dairy products as yoghurt and ice cream. In US the milkshakes and dairy smoothies are popular. English add milk to their tea and French are known for their Café au Lait. Many countries drink their milk in the form of hot chocolate.
Of course cow is not the only animal kindly sharing their milk with us. Also goats, lambs, camels and horses do that in some cultures at least. I have never used any other animal’s milk than cows milk for frothing. If some of you have, please share your experiences in the comment box below this posting or sending us PM via Instagram.
What milk exactly is?
Watch out. My inner nerd and chemist is released! ? Luckily I am not the only one getting excited, our friends at Perfect Daily Grind did too!
Cow milk is actually an emulsion. Here you can see the division of substances.
Note: the process might vary a bit between different processing plants and countries.
Separating the fat from milk creating cream and skimmed milk.
Adjusting the fat content to the target level.
A mild heat treatment which eliminates pathogens and leucocytes and to extend shelf life.
- HTST (high temperature short time). Quick heating up to +72 degrees Celsius for 15-20 seconds, then fast cooling down below +6 degrees Celsius. This does not have a significant effect on chemical composition, nutritional value nor the taste of the milk.
- ESL (extended shelf life). Quick heating typically up to +125-135 degrees Celsius for 1,5-2 seconds, then fast cooling down below +6 degrees Celsius. This does not have an effect on chemical composition, nutritional value nor the taste of the milk.
- UHT (ultra high temperature). Quick heating typically up to +135-138 degrees Celsius for 2 seconds, then fast cooling down below +6 degrees Celsius. This sterilizes the milk and extends the shelf life allowing also storing in om temperature. Milk loses hardly any of its original properties but it can taste slightly like boiled.
- Sterilizing. In some countries milk or dairy products are sterilized. By doing this it is possible to produce conserved products that can be stored in room temperature for over a year. Milk tastes like boiled and it might be a bit brownish. The nutritional value of the milk is changed.
In addition to the three steps above, the milk might go through many other steps like the ones below. They are listed in the order of execution and all of them are done before pasteurizing.
Proteinizing or deproteinizing:
Adding protein to maximize the milk steaming and foaming properties or removing whey protein to make it easier not to burn the milk while boiling it for instance when making porridge.
Lowering the lactose content i.e.. making low lactose milk or lactose free milk. This is done by using lactase enzyme to split lactose in two separate parts. Lactose is a disaccharide and when it is split in two, the remaining parts are monosaccharides named glucose and galactose. This processing makes the milk a bit sweet in taste. Depending on the degree of hydrolysis, the milk can be either low in lactose or lactose free.
Lactose is partially removed and the rest is hydrolyzed to maintain the original taste of milk. In this process, part of lactose is not chopped down but taken away. The remaining lactose is then hydrolyzed using lactase enzyme. It is noticeable that during this process, also energy of the lactose is lost.
Adding vitamin D3 to the milk.
Spraying the milk with high pressure through a small hole to chop down the fat balls. This is done to add the viscosity of the milk and to prevent the separation of the fat and to maintain emulsion during storage. This step also spreads the added vitamin D3 evenly to milk. Homogenizing is completed with stabilizing the milk so that the fat balls don’t gather up again.
NOTE: Reducing fat and adding some vitamins are basic processes after which the product can still be called milk. Other manipulations mean that the product is called milk drink, not milk.
Can cow milk composition vary somehow?
EU is regulating the composition and microbiological quality of milk. National regulations can be tighter than EU regulations.
The following factors have an effect on the milk:
- breed, health and age of the cow
- stage of lactation period of the cow
- feeding, diet, nutrition intake of the cow
- surrounding circumstances and time of the year: for example in Finland summer time means low protein content and on the other hand November highest possible protein content
Lactose intolerance is a topic that easily creates discussion.
Most intolerant people can usually consume some regular dairy products. Some say the less the milk has been manipulated, the less symptoms it creates. Also consuming dairy with lactose at the same time with some food might rise the tolerance for the time being. Sour milk products as yoghurt are usually more tolerable than the regular dairy products, This is because some of the lactose is chopped down during sour culturing.
As stated on Finnish Food Authority’s webpage, no common limit values have so far been defined at EU level for the lactose content of low-lactose and lactose-free food products. The following values have for quite some time been applied in Finland as Nordic limit values:
- Low lactose milk: less than 1 g lactose / 100 ml milk
- Lactose free milk: 0,01 g lactose / 100 ml milk (this applies also for many other European countries)
Why milk is white?
In milk there are, among other substances, insoluble fat droplets and insoluble white casein balls. White colour is created when surrounding light scatters from those particles. In case fat is removed, the light scatters in a bit different ways and this might change the tone of white color.
As milk and it’s behavior in baristas’ hands is a very interesting topic, I will soon send out another blog post about this. Stay safe and enjoy your daily dose of milk!