Your love for Coffee is not by chance. Quality Coffee goes through thorough selection processes before it becomes your favorite latte, cappuccino, or other espresso drink. However, Coffee is not the only ingredient that makes your Coffee drink superb; milk is just as essential to your Coffee’s outcome. How well you froth your milk plays almost the same role as how you grind your Coffee.
If you are a staunch coffee lover who never skips his or her coffee drink at the start of the day, you will testify that frothed milk has its unique taste that you can identify just with a roll of the tongue.
If you love to make your coffee drink yourself and still not compromise its excellence of taste, you must wonder if you can froth your milk at home. The answer is yes. Having some understanding of the science and chemistry around milk frothing may help you make the best-tasting coffee drink within the comfort of your home.
What is frothed milk?
Its milk in which air has added to. This aeration process creates bubbles or foams and helps the milk achieve a creamy consistency. Most coffee shops use Milk frothers which work by forcefully spinning the milk around with a spiral whisk. These frothers also push steam through the milk, thereby creating bubbles and giving it a creamy texture.
Why froth milk?
Why is frothed milk important for a coffee drink? Is heating the milk not enough?
These are questions that might run through your mind if you want to simply have a cup of Joe in your hands but not quite. You see, frothed milk adds a perfect layer of cream to any beverage at all. It adds a certain richness and texture to your drink that is better experienced or tasted. Froth milk is for those who want to take their coffee drink to the next level or bring different styles to their drinks per time. It is an essential component that makes up the creamy feel of the Coffee in your mouth. You can always add regular hot milk to your Coffee, but there is no denying it will taste ordinary.
Also, for those who care, frothed milk not only adds a different flavor to your Coffee but can be used to create excellent latte art. Yes, you know those beautiful coffee pictures you see on Instagram.
Another benefit of a coffee drink made with frothed milk is that you taste more flavors on the sip. This is because the bubbles change the surface tension of the Coffee, biochemically allowing more taste buds to come up. You see that how you feel about Coffee made with frothed milk is not just in your head. Your taste buds really do come alive.
Lastly, many believe that frothed milk works as an insulator, keeping your coffee drink warm for longer.
Most popular coffee drinks, such as Cappuccinos and lattes, all require some frothed milk. Without its foam, you will not get to enjoy that smooth, filling, rich body.
Components of Milk
Milk is one of the significant ingredients when making your coffee drink. Understanding the basic chemical compositions of milk will better improve your chances of making a quality coffee drink for yourself. Cow milk is highly nutritious, comprising water and other chemical compounds. These compounds are proteins, lipids, carbohydrates, sugars, and minerals.
Milk Proteins are the components most affected by the heating process and determine the frothing process’s success or failure. These proteins have different structures and sizes spread through the liquid when we force air into it. The air or vapor causes the proteins to create spheres around the air, which stabilize to become bubbles. The temperature of about 60oC (140oF) results in more stable foam with fine texture and thickness, while smaller air bubbles are formed at higher temperatures.
The fat content of milk plays a significant role in stabilizing these bubbles by preventing them from joining together to create more giant bubbles. This is why you notice a film on the surface of the air bubbles. However, you still have to be careful when heating your milk as too high-temperature results in scalded milk which tastes sulphuric and causes the foam to fail. Also, overheating denatures your milk’s protein content, so there will not be enough left to cover the air bubbles and protect them from coalescence. This explains why it is terrible to reform milk because the reheating process destroys every protein left to stabilize air bubbles.
What kind of Milk is Best for Frothing
When deciding on the best milk for your coffee drink, the primary requirement is its protein content since, without proteins, your milk won’t foam. There are different types of milk up for debate. Read on below:
Whole (also known as full cream) has higher calories contents. Whole milk creates a thicker, creamier foam, when frothed which adds body and richness to your coffee drink. Frothed whole makes for the most stable foam you can ever get. It is also most ideal for latte art.
Skimmed is much lighter and does not contain as many fats like whole milk. However, its protein and other essential nutrients remain intact. Skimmed milk creates larger air bubbles than whole milk. Skimmed will give you the most stable foam but may not have the creamy feel you desire as achieved by whole milk.
Soy is the most popular of all milk alternatives. It is easy to froth but does not create as much foam as cow milk. If you have decided to use Soy, then you have to go for low acidic coffees as Soy reacts to acids in coffee, which can ruin the consistency of the milk, making it clump up and make the foam go down.
Oat is a much better option than Soy when it comes to frothing. Not only is Oat milk easy to froth, but it also contains higher protein content than other dairy alternatives, which makes it foam well. Oat milk seems to get thicker as you continue to heat it.
Almond is a great option as long as you froth it well. Some find its taste too strong for coffee.
Best Frothing Temperature
The outcome of your frothed milk depends on the temperature at which you heat it. Ideally, you should heat your milk between 60–63oC (140–145oF) degrees Fahrenheit. If heated below this temperature, your milk will get unstable foam and large bubbles. You must also make sure not to exceed 160 degrees temperature as the heat can denature the protein content, and the milk will start to boil. If your milk boils, it will no longer be possible to have microfoams.
You can use a thermometer to monitor the temperature. There are specially designed milk frothing thermometers, but any kitchen quick-read thermometer will do. When using a thermometer, ensure you remove the steam wand before the thermometer reaches 160 degrees as the temperature will continue to rise for a few seconds after the wand has been removed.
The Difference between Steaming and Frothing
Many are often confused about milk frothing and steaming. For an average coffee drinker, the difference between the two might be overlooked, but not to the coffee enthusiast. Steaming and frothing are two different processes that ultimately produce different types of milk. Steamed milk is less thick than frothed milk.
When using an Espresso machine, steamed milk is produced by heating milk with a steam wand. The coffee maker places the steam wand tip just beneath the surface of the milk in such a way that the milk spins in the bowl. The milk must be evenly heated.
Frothed milk goes a little further than steamed milk. The coffee maker not only heats the milk with the steam wand but also injects air into the milk. This process creates small bubbles, which become the much-coveted foam on the coffee drink. Using an Espresso machine, the coffee maker puts the steam wand tip on the surface of the milk. As the milk continues to expand in volume, you will need to lower the wand to pull in more air and create larger, stiffer bubbles. A common cappuccino drink is made with both steamed and frothed milk.
How to froth milk at home
If you want to always enjoy the creamy taste of coffee, you can also froth your milk at home. Check out the different ways to froth your milk at home and decide on which is more convenient for you.
Your basic requirements to froth milk at home are milk and a clean bowl.
Heat your milk
The first step when frothing your milk on whichever method is to heat your milk between 60–63oC (140-145oF). If you do not heat your milk enough, it will not taste as sweet it should. Yet, if you overheat the milk, it will not foam well.
Groom the milk
Your frothed milk can turn out better if you groom it by swirling the milk and taping your frothing container on a surface to pop large air bubbles.
Different methods of frothing milk at Home
Shaking in a jar
Place your already warmed milk in a tightly closed jar, then shake the jar very well. This method creates foam with large bubbles. If your milk is quite hot, hold the jar with a dishtowel so you do not burn your palm.
Whisking by hand
Put your warm milk in a bowl and use a balloon whisk to whisk it vigorously by hand. You can whisk in a back-and-forth or circular motion. Frothed milk by whisking is usually of better quality than the jar shaking method.
Using an Electric mixer
After heating milk, use an electric mixer to whisk the milk until it reaches the desired frothiness. The foam created via this method is of more quality than being whisked by hand.
Using an Espresso Machine
This method is for those who invest in an Espresso machine for ease and perfectly frothed milk. Immerse your frothing wand into the warm milk and then turn it on. The wand will keep swirling the milk and create nice foams to your desire. A frothing wand makes very nice foam.
Use a blender
After heating your milk, pour it into a blender and put it on medium speed until it is as frothy as you desire. When using this method, ensure you cover the lid of your blender tightly, so you do not have hot milk flying everywhere and hurting you. Bubbles made from the blending method are equally good and uniform.
Immersion blending method
Pour your warm milk into a large, deep pot. After which, you put your hand blender in the milk, making sure the blades are deep in the liquid. Put on the blender on a low level so that the milk does not splatter around the kitchen.
Blend until it is as frothy as you desire. The immersion blending method creates nice foam but can be messy if it is not done in a deep pot.
A pump frother is a manual frother. After heating the milk, let it cool for about a minute before pouring it into the frother. Pump the milk vigorously and quickly, using the plunger handle. This should go on for about 30 seconds while you keep holding the cover.
The quicker and more vigorously you pump the milk, the more aerated the milk will become and the better foam it creates. A pump frother makes lovely, creamy foam.
Make sure the frother is not too full since the milk expands as you keep pumping. Use a hot pad when holding the cover down, so you do not burn your hands.
You can use a French press just like you would use the pump frother. Pour your warm milk into the French press and pump up and down while holding the lid down with your other hand. Do this until you have the froth as thick as desired. When using a French press, make sure you do not fill it to the brim since the milk expands as it froths.
Reheating frothed milk
Reheating frothed milk is a bad idea. Here is why?
Milk is a whole food containing almost all nutrients. This means it can easily grow bacteria and other harmful pathogens. If milk is left sitting on the counter, these bacteria can multiply quickly. Reheating the milk cannot kill off any bacteria or other ill-causing agents. Another reason not to reheat frothed milk is that the heat causes the proteins to break down, making the milk watery and altering its taste. It is always best to froth the right amount of milk you need at a particular time.
Why does your Milk not froth?
Even experts can testify to this, that after using the best milk, following the same process as the last time, sometimes the milk just does not froth. You do not need to beat yourself up over this. Even more mysterious is how some milk will only form foam then disappear in seconds. A reasonable explanation for this is enzymes or bacteria that attack the fact component in the milk, causing components such as free fatty acids, monoglycerides, and diglycerides to form in a process called lipolysis. If these new compounds are too much, they will cause the foam bubbles to burst.
Going further, this is also not your fault. Lipolysis can be a result of the cows’ feeding, lactation cycle, poor weather conditions, milking technique, or improper storage at home. When milk refuses to froth, there is not much you can do about it other than to hope your next attempt will be better. However, keep in mind that fresh milk froths better than refrigerated milk. If you have to, store milk in the refrigerator at 40°C (4°C).
Best Practices when Frothing Milk
Below are tips that can make you an expert at frothing milk
Start with cold milk
Asides from the fact that already cool milk takes air better, it also gives you more time to work it.
Do not fill your bowl to the brim.
Always remember that milk expands when frothed. Try pouring just as much milk to where it starts to foam. This will be enough for a large latte.
When using an Espresso machine, ensure it is up to steam temperature. Some machines will turn off and stop generating steam while you are still frothing. The trick is to calculate the amount of time the machine needs to get to steam temperature. You can start steaming a few seconds before the machine indicates it has reached full temperature.
Purge your wand
Use a towel to wipe your steam wand just before you start the process to remove any water that has been in the steaming circuit. You do not want extra water in your milk. After frothing, repeat the purging process to remove any milk from the wand.
Frothing is quite an easy step that you can only get better at. Learning to froth milk by yourself and in the comfort of your home is a huge win for a coffee enthusiast. Try these different methods and let us know how it goes.