Begin by calculating the flow rate, which is just the quantity of water that flows out of your group head per unit of time the pump is working.
In other words, it determines how quickly or slowly the water emerges from the espresso machine during the brewing process.
Not only will the extraction time alter if you don’t have the proper coffee flow, but the espresso flavor will change as well. Coffee will extract more or less depending on how much water you use.
This means that if one coffee extraction group’s heads have a heterogeneous or often variable flow (sometimes fast, sometimes slow), it can lead to significant coffee extraction issues.
When There Is An Uneven Flow Rate
To learn more about flow, consider the following example: You’ve set the grinder for a specified amount of time and weight in your coffee [bar], and now you want to extract your coffee from 20 words grams to 38 grams in roughly 20 seconds.
Let’s imagine one of your buckets has less traffic than the other, or you have more traffic on the fifth extraction after that.
Here’s how it’ll play out:
- When the extraction ratio is lower: You’ll extend the time the coffee and water are in contact and reduce the pressure inside the filter basket, which is the counter-pressure inside the basket filter, not the pump pressure.
- “You will reduce [extract]… moreover the pressure inside the filter basket will alter” with a more excellent extraction ratio.
- The espresso’s taste and quality are affected by each occurrence’s exposure time and pressure fluctuations. This negates all of your efforts in extracting and modifying the recipe and, of course, results in coffees with erratic flavors.
What Causes Inconsistent Flow Rates?
The regularity of your flow might be affected by various factors, including pump failure, worn parts that need to be replaced, or old equipment.
It isn’t just about your device, though. It also depends on how you use and care for it. It’s not a problem with the pump, especially with high-end machines. When utilizing a mixer with two group heads, users may not clean the group head correctly or may only use one of the group heads frequently.
Always keep in mind that high-quality equipment necessitates regular, meticulous cleaning and maintenance by the manufacturer’s recommendations.
Flow Rate Calculation Made Simple
Coffee machine makers recommend that anybody who owns an espresso machine, whether in a coffee shop or at home, calculate the machine’s flow rate. Repeat this process for each group leader at least twice to ensure accuracy.
For example, you place an electronic scale at the bottom of the machine and a graded flask at the top of the group, then start the pump and the timer simultaneously and complete the task in 20 seconds.
Let’s imagine you have 200 grams of water, and you’re extracting 10 grams each second because you’ve previously extracted using 20 seconds and 200 grams of water.
Is a Variable Flow Rate Better for Espresso?
However, maintaining a steady flow rate is only the beginning of employing flow rate to make excellent espresso.
Yes, you want a consistent and reproducible scale throughout the extraction, but that doesn’t mean it must be the same. Controlled adjustments in flow rate can help you make finer, tastier espressos.
A professional espresso machine 1 Group allows you to adjust the flow rate between extractions based on a previously defined preset.
You can make the coffee permeable in various ways by adjusting the flow rate for a specific duration or length of time during extraction. As a result, there are numerous ways to extract taste from the coffee.
How to Make a Better Espresso by Controlling the Flow Rate
What flavors are you able to achieve by adjusting the flow rate? You can minimize the bitterness, the acidity, and the acridity…
There is no uniform answer, but based on personal experience with particular baristas, the extract is likely to be sweet, complex, and acidic. However, there must be a modest flow from the start.
Flow rate is a frequently overlooked aspect of espresso production, yet it significantly impacts quality and consistency.
Water pressure vs. water flow rate
Let’s start by defining the distinction between water flow rate and water pressure. They may sound similar and have to do with friction, yet they are vastly different. The amount of water that comes from your faucet in a certain amount of time is your flow rate. The logic for calculating your water flow rate is broken down here.
In contrast to air pressure, water pressure is determined by gravity rather than speed. Water pressure in your home refers to the force used to move water from point A to point B.