Guide · As of October 2026
E61, Bezzera BZ, saturated group, thermoblock: the brew group is the heart of an espresso machine. It determines how quickly the machine is ready, how it needs to be maintained and which portafilter fits. Here you will learn which types of groups exist, which ones are found in machines we carry and what that means for your accessories.
In short
- The group determines heating and maintenance, not the tamper size. That depends on the basket; see the tamper guide for more.
- Portafilters are tied to the group. 58 mm on two machines does not mean the portafilter from one fits the other.
- With Bezzera the name suffix matters: MN stands for the E61 group with lever, DE for the electrically heated BZ group with push button.
- No group is universally the best. More important are how you use the machine, how quickly you want it to be ready and how much maintenance you want to do.
Overview of group types
| Group | How it heats | Warm-up time according to the manufacturer | For example in our range |
|---|---|---|---|
| E61, classic | Thermosiphon: hot water circulates from the boiler through the heavy brass group | Rocket specifies 15 to 18 minutes, Lelit for the Mara X 24 minutes | Rocket Appartamento and Giotto, Bezzera Aria, Unica, Magica, Duo MN and Matrix MN, Quick Mill Rubino, Lelit Mara X with Lelit’s E61 variant L58E |
| E61 with auxiliary heater | E61 construction with a heating element and sensor mounted directly on the group | Rocket gives about 12 minutes for the Fast models | Rocket Giotto Fast, Mozzafiato Fast, R58 Tune, Bezzera with Fast Heating (Sole Top, Luce S, Aria Top) |
| Bezzera BZ | electrically heated group with heating cartridges, brew by button and solenoid valve | no minutes specified | Bezzera BZ10, BZ13, Duo DE, Matrix DE |
| Saturated or integrated | The group is mounted directly on the coffee boiler and is flowed through by its water | La Marzocco: Micra about 5, Linea Mini about 10 minutes to espresso temperature | La Marzocco Linea Micra, Linea Mini, GS3, Rocket R Nine One |
| Sanremo | varies by model: YOU with SR61 group and dedicated PID group heater, Cube with thermosiphon, Café Racer with saturated groups | no minutes specified | Sanremo YOU, Cube |
| Dalla Corte Multiboiler | each group has its own small boiler, independently regulated | no minutes specified | Dalla Corte Studio, Studio Aqua, XT |
| Quick Mill thermoblock | Quick Mill’s own group; the water is heated in the flow heater | Pegaso: 45 to 50 seconds to operating temperature | Quick Mill Pegaso, Orione, Luna, Cassiopea |
| Own constructions | Stone: heavy brass group with its own PID heater. Superkop: lever operation without electricity, hot water comes from the kettle | Stone about 10 minutes, Superkop needs no warm-up | Stone Mine, Superkop |
The times are manufacturer specifications with different criteria, for example "ready" or "group stable." They are therefore only roughly comparable. Sources conflict regarding the Rocket R58 Cinquantotto on whether the group is saturated or an E61. We have therefore not classified it.
What the group means for your accessories
Portafilter
The portafilter latches into the group with its ears. The shape, position and thickness of these ears differ by group, even when both are 58 mm. One example from our range: For Bezzera there is a bottomless portafilter for the E61 group and a separate one for the BZ group. The two are not interchangeable.
Baskets
Baskets are more often interchangeable than portafilters. IMS assigns its 58-series B70 baskets to, among others, Rocket, Bezzera, Sanremo, La Marzocco, Quick Mill and Lelit, including the BZ portafilters from Bezzera. Check two things: does the rim fit your portafilter, and is the portafilter deep enough for a taller basket? It is different for Dalla Corte with the 54 mm standard and for Lelit’s 57 group: there you need the matching smaller baskets.
Shower screen
The shower distributes the water over the coffee and is group-specific. An E61 shower will not fit a La Marzocco or a BZ group. Same tamper size does not mean the same shower.
Dose
How much coffee fits into the basket without the puck touching the shower depends on the basket and the distance to the shower, not on the group type. A table saying "E61: up to 22 g" would be misleading. Follow the basket manufacturer's range. For example, VST states 17 to 19 g for its 18-g basket and 21 to 23 g for the 22-g basket. If the puck shows a clear imprint of the shower after brewing, it was too much.
Maintenance: what differs by group
- E61: The lever moves a mechanism inside the group. It occasionally needs some food-safe grease, especially if you backflush often with cleaning agents. How often is stated in your machine manual.
- BZ and other groups with a solenoid valve: There is no lever mechanism in the group. Backflushing and cleaning the shower are still necessary.
- Saturated groups: They are not maintenance-free. Shower, gasket and baskets need the same care as with other groups.
- Quick Mill thermoblock: The group is its own construction. Do not transfer E61 backflushing procedures without checking; follow the Quick Mill manual.
For all groups: soft water protects the machine; more on that in our article Do I need a water softening system for my portafilter machine?
Which group suits you?
You like the classic lever and have time in the morning: An E61 is robust and widespread, spare parts are easy to get. With a timer it is warm when you get up.
You want to start quickly: An E61 with an auxiliary heater like Rocket Fast models or Bezzera Fast Heating, a BZ group or a saturated group are ready noticeably earlier.
You want to set temperature precisely and drink a lot of straight espresso: Then consider dual boiler machines with PID, regardless of whether they use E61, BZ or saturated groups. More on this in our portafilter machine guide from 1.500 bis 3.000 €.
Frequently asked questions
Will an E61 portafilter fit my Bezzera BZ?
No. Bezzera offers portafilters for the E61 and for the BZ group separately. A 58 mm tamper and many baskets can still be used on both.
Will a bottomless portafilter from another brand fit?
Only if it is explicitly made for your group. "Bottomless" describes the missing bottom, not a connection that fits everywhere. For E61 machines there are many suitable portafilters, for example the original from Rocket.
Do I need a different tamper for a BZ group than for an E61?
Not because of the group. The decisive factor is the basket.
Does the Dalla Corte Studio have 54 or 58 mm?
Standard is 54 mm; Dalla Corte lists 58 mm as an option. Check which portafilter is fitted to your machine before buying accessories.
Does espresso from 54 mm taste better than from 58 mm?
A narrower basket produces a taller puck for the same dose, which often requires a slightly different recipe. Dalla Corte markets it as giving more body. We have not found independent evidence that 54 mm is inherently better tasting.
Is a saturated group always better?
No. It is usually ready faster, and manufacturers describe it as particularly temperature-stable. A well-tuned E61 also makes excellent espresso; it just needs more time to heat up.
Our advice
Choose the machine according to your daily routine, not the group name. And before you buy accessories, check which group your machine has: the group decides portafilter and shower, the basket decides the tamper. If you are unsure, tell us the exact model designation and we will tell you what fits.
