The perfect cup of espresso is not something that happens by chance. That golden crema, body, and perfect bittersweetness require precision and discipline. Temperature plays a key role in extraction yield and taste. Most people rely on their espresso machine to automatically pick the temperature for them, but you can do so much more by adjusting and maintaining the water temperature to make your perfect espresso.
Water Temperature and Espresso Taste
Many variables go into making a great espresso, like the right roast, grind, and water to coffee ratio. Water extracts the flavor from the coffee grounds, a process called extraction. Different temperatures affect the extraction rate and ratio, influencing the espresso’s taste, for bad or good. Therefore, to get the right flavor, the water temperature has to be precise.
The National Coffee Association determined that the optimal temperature lies between 195° and 205° Fahrenheit. Science confirmed that perfect range. Within those temperatures, the bean’s flavor compounds are water-soluble. Those compounds may not dissolve at lower temperatures, and you’re left with weak espresso with an acidic and sour flavor. Higher temperatures over dissolve, and the espresso tastes bitter and burnt.
The water temperature also optimizes the brew time. Low temperatures extend the usual 20 to 30-second brew time. Consequently, the espresso’s body and sweetness alter and not for the better. High temperatures may reduce the brew time, but (again) you’ll end up with burnt espresso.
Adjusting Brew Temperature
You have more control over the espresso’s flavor than you might think. Yes, you can stay within that optimal temperature range. However, you can make small differences in the taste by adjusting the temperature. There are a couple of reasons why you might do that. One is personal preferences. However, a more important reason is that changing the brew temperature lets you compensate for less than ideal factors outside of water temperature that affect the espresso’s flavor.
For example, sometimes you end up with an overdeveloped roast. If you know that, you can increase the extraction yield by lowering the brew temperature. Less extraction balances out the flavor of the overdeveloped roast.
You can adjust the temperature by either using a temperature control kettle or relying on a simple but accurate thermometer. Measure the slurry temperature. (The slurry is the part where the grounds and water mix at the top of the vessel.) From there, adjust the temperature according to the readings to either stay within the optimal range or compensate for variations in roast or grind.
A few tips to help you through the processes:
- Warm the vessel beforehand by pouring boiling water into it.
- Boil the water, then let it sit a few minutes before pouring it over the grounds because the optimal water temperature is lower than water’s boiling point.
- Grind your beans close to brew time.
- Don’t reuse grounds.
Manipulating the Extraction Variables
The perfect extraction level doesn’t come from the water temperature alone. Your equipment, the grind, water-to-coffee ratio, brewing pressure, and brewing time all work together with the water temperature. Changing any one of these variables will be noticed by your taste buds.
The Grind
There are two types of grinders—blade and burr. Blade grinders chop the beans like a fan, but the inconsistency in grind size makes them a poor choice for an espresso grind. Burr grinders create a finer, more consistent grind that’s better suited to espresso’s taste balance.
A grind that’s too fine can add too much bitterness to the espresso, while a grind that’s too big leaves the espresso weak and flat. Every grinder is slightly different, so you may have to experiment to find the right grind settings. However, a setting between 3 and 8 usually works for most machines.
Water-to-Coffee Ratio
There’s some variation in the right water-to-coffee ratio based on personal preferences and how much water evaporates during the brewing process. However, a good rule of thumb is one or two tablespoons of ground coffee per six ounces of water. Check the measurement lines on your machine and make adjustments according to your personal preferences.
Brewing Pressure
The ideal brewing pressure—pressure created during extraction—falls between eight or nine bars. Not all machines have adjustable pressure. Those that do may let you set the pressure to as high as 14 or 15 bars. A high brewing pressure increases the extraction rate and can cause extra bitterness if you’re not careful. However, if you have an adjustable machine, you can use the brewing pressure and water temperature to maximize extraction and minimize brewing time.
Brewing Time
The amount of time the water stays in contact with the coffee beans influences the flavor. Coffee brewing times vary by machine. Drip systems ideally take five minutes. A French press, on the other hand, only needs two to four minutes of contact.
But espresso isn’t the same thing as a typical cup of coffee. Its brewing time should be a quick 20 to 30 seconds. You can increase or decrease the brew time to change the flavor. If the coffee ends up weak, extend the brewing time. If bitterness is an issue, shorten the brewing time.
FAQs
What is the difference between coffee and espresso?
Espresso is made with coffee beans, so what is it exactly that makes one cup espresso and another coffee? Three key differences come into play when making an espresso instead of coffee. First is a dark “espresso” roast. Espresso is essentially a shot of coffee with maximum flavor. A darker roast provides a quicker burst of flavor in espresso’s short brew time.
Next is the grind. Again, you need maximum flavor for minimum extraction time. That requires a finer grind of the coffee beans to make good espresso.
Pressure is the third factor that’s different between these two popular drinks. Espresso is made under high pressure to increase the flow rate and decrease the brewing time. Pressure changes alter the flavor, so you can increase or decrease it to change up your espresso recipe.
How many grams of coffee are in an espresso?
A shot of espresso typically contains seven to nine grams of coffee. Consequently, a double shot contains 14 to 18 grams. However, those numbers vary in different parts of the world and even from coffee shop to coffee shop. Some use 16 to 19 grams of coffee per shot, putting a double shot even higher.
Why is my espresso not hot?
We’ve just gone over how important temperature is to the brewing process. Temperature continues to be important until you’ve completely consumed your espresso. The temperature of the espresso drops to about 160° Fahrenheit once it hits the cup. That’s the temperature that’s usually comfortable to drink without scalding. From there, each degree it drops alters the taste. Thankfully, a shot is small.
Try pre-warming the vessel in which the espresso is brewed. Pour boiling water into it before placing the coffee grounds and water in for extraction. You can warm the cup beforehand to maintain the temperature as well. Like the vessel, fill the cup with boiling water a few minutes before your espresso is ready.
Final Advice
Like any craft, making espresso takes time to develop true skill. It may also take time to find the variables that create your perfect espresso. Experiment with the roast, grind, water temperatures, pressure, and brew times. You could discover that you haven’t even tasted your perfect cup yet because you’ve yet to know how to make it.
