In order to extract excellent espresso and experience a coffee’s full range of flavours and aromas, a high-performance grinder is essential.
High-quality grinders help to ensure more even and consistent grind size distribution – ultimately leading to better extraction. However, there are a number of different types of grinders, including timed and gravimetric models.
While both types of grinders can produce high-quality results, each one has its own impact on consistency and accuracy.
To learn more about the differences between timed and gravimetric grinders, and the benefits of using the latter, I spoke with Giulia Bagato, Marketing Manager at Fiorenzato. Read on to learn more about her insight.
You may also like our article on which material your grinder burrs should be made from.
What are timed and gravimetric grinders?
While both timed and gravimetric grinders can produce excellent espresso, there are some notable differences in how they grind coffee.
Gravimetric grinders measure the weight of the coffee as it is ground and dispensed into the portafilter. Once the pre-programmed weight has been reached (which is determined by the user), the motor will automatically shut off.
“Grinding by weight means that you can select the amount of coffee you need to be dispensed into the portafilter, including for single and double doses,” Giulia says. “This means you will always receive the exact amount of coffee you need.”
Timed grinders (also known as on-demand grinders), meanwhile, grind based on a pre-set time, which is also determined by the user. For example, if a barista needs 18g of coffee, and it takes around six seconds for the grinder to dispense this amount, then the pre-set time needs to be six seconds.
“The main difference between gravimetric and timed grinders is that with the former, you directly select the desired amount of coffee,” Giulia says. “Conversely, with timed grinders, you can often only set the number of seconds it takes to grind the coffee.”
Ultimately, knowing how many seconds are needed to grind the right amount of coffee can require some trial and error. It may take several attempts to reach the required dose, which can lead to higher levels of coffee waste.
Giulia explains that when you grind by weight, it is often more efficient compared to grinding coffee by time.
“You can quickly dispense the right amount of coffee without continuously adjusting the number of seconds, and then weighing the portafilter to know whether you need to increase or decrease the time,” she tells me.
Improving grinding accuracy and consistency
When pulling espresso shots, there are many variables that baristas need to account for – including dose, yield, extraction time, and grind size.
In order to improve workflow as much as possible, grinding consistently accurate doses is important. This allows baristas to work faster, while still maintaining high-quality beverages and giving baristas more time to serve customers.
However, baristas will need to change grind settings throughout the day to get the best out of a coffee. If they adjust the grind size and make it finer, for instance, this means the coffee will take longer to grind.
When using timed grinders, this means the time it takes to reach the required dose will need to be increased. During busier periods, adjusting this could take a significant amount of time for baristas – even for those with more experience.
Moreover, bean brittleness and size can also impact grind time. This means that when using timed grinders, baristas need to adjust the time it takes to grind each type of coffee they use.
Timed grinders are also more affected by the volume of beans in the hopper than gravimetric grinders.
For instance, when the hopper is more full, the weight of the coffee pushes more beans into the grinding chamber – which means the coffee grinds faster. However, when the hopper contains less coffee, it can take longer to grind the beans.
Meanwhile, when you grind coffee by weight, it tends to produce more consistently accurate doses – typically with a 0.1g range to the required dose.
However, because of this precise technology, Giulia mentions that some gravimetric grinders can be sensitive to their environments.
“If the scale balance in the grinder is too sensitive, any kind of vibration or disturbance may disrupt it, which means it may not tare or weigh the dose accurately,” she says.
She mentions that Fiorenzato’s new XGi grind-by-weight technology (which is included in the F64 EVO XGi Pro and F83 E XGi Pro models) helps to overcome these issues.
“The XGi technology includes a built-in system that first weighs the whole grinder, and then calculates the weight of the dose according to the difference in weight once it is dispensed,” she says.
What are the other benefits of grinding by weight?
Gravimetric grinders are steadily becoming more popular among coffee professionals, largely because of their accuracy and consistency.
“Gravimetric grinders like the F83 E XGi Pro ensure that baristas prepare consistent and high-quality coffee for all of their customers, using the correct weight of ground coffee according to a set recipe,” Giulia explains. “The XGi technology’s load cell at the base of the grinder works with integrated software to constantly monitor the total weight of the grinder.
“It ensures that the difference in weight after each dose is dispensed corresponds to the required amount in grams,” she adds.
Giulia explains that Fiorenzato’s load cell feature spans across the base of the grinder, and helps to improve accuracy when weighing doses.
Baristas already have to account for many different variables when preparing coffee, so gravimetric grinders can help to standardise the process and achieve more consistent results.
Moreover, when you grind by weight, it can also help to reduce coffee waste. This is because baristas don’t have to pull as many shots to make sure the grind time corresponds with the required dose, and also ensures that doses aren’t too large.
On a similar note, gravimetric grinders help free up baristas’ time.
“If a barista needs to change the grind size at any point during the day, the Fiorenzato’s XGi software automatically recalculates the correct dose within a maximum of three doses to always ensure the correct grind size,” Giulia explains.
Ultimately, this means baristas will need to spend less time tweaking grind size – thus allowing them to focus more on other tasks.
“Furthermore, we have developed the touchscreen interface to be more intuitive, as well as introducing the ability to check the scale function throughout the day,” Giulia adds.
Tips for using gravimetric grinders
Switching between timed and gravimetric grinders can take some practice, but it will ultimately help to improve workflow and efficiency.
For both types of grinders, ensuring that the hopper remains around three-quarters full at any given time will help to maintain accurate dosing. While gravimetric grinders are less affected by this than timed grinders, the weight of the beans will ensure more consistent doses.
Clumping can also be an issue for gravimetric grinders. This occurs when fine coffee grinds stick together inside the grinding chamber, some of which remain on the burrs. This can mean pulling shots with stale coffee, as well as potentially damaging the grinder in the long term.
To avoid these problems, it’s essential to regularly and properly clean and maintain your coffee grinder.
Furthermore, remember that while many gravimetric grinders, like the F83 E XGi Pro, include grind-by-weight technology which automatically recalibrates your dose when changing the grind size, some models do not.
In these cases, it’s important to calibrate your grinder as often as possible. When doing so, aim for lower doses to reduce coffee waste as much as possible. And regardless of how accurate and precise your gravimetric grinder is, it is still important to always weigh your doses to ensure they are accurate.
The type of grinder you use will have a significant impact on the overall quality of your espresso. Now more than ever, coffee professionals are using gravimetric grinders to improve the consistency and accuracy of their doses.
If you’re looking to extract excellent espresso and get the best out of your coffee, investing in a high-quality grinder which includes grind-by-weight technology could be one of the best ways to do so.
Enjoyed this? Then read our article on cleaning and maintaining your coffee grinder.
Photo credits: Fiorenzato
Perfect Daily Grind
Please note: Fiorenzato is a sponsor of Perfect Daily Grind.
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