In this page, you can figure out the difference between the different machines. Just look under the features and see what characteristics are important to you.
FREQUENTLY ASKED QUESTIONS
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Differences between groupheads
BZ Thermal Efficient
Produces espressos with sharper clarity.
Less space for remnants to get retained, which can cause a “dirty” taste from stale and decaying coffee.
Faster startup and recovery time.
More reliable with a better engineering design.
Affordable long-term repair.
Slightly smoother extraction with a period of pre-infusion.
Components are easily available worldwide.
Dynamic pressure profile that releases a wider spectrum of aromatic notes.
A larger amount of preinfusion for smoother extraction.
Affordable long-term repair.
Has the pre-infusion found in E61.
Less wearable components.
Difference between E61 or BZ?
The BZ grouphead can be seen as a redesign of the E61 which was invented almost 60 years ago. The main idea is to create a machine that is smaller, more serviceable, safer and reliable. Particularly important when it comes to industrial usage. BZ is also a little less pricey as E61 utilizes a lot of metal used for its grouphead.
E61s are easy to use, easy to pull a nice looking shot mainly due to its inherent process of forming a pre-infusion. Pre-infusion is to allow water to spread evenly above the coffee powder before pressurization for extraction takes place. This can reduce channelling issues happening during extraction. However, it does come with some shortcomings. Remnants are often retained in the compartments where pre-infusion builds up. Such retention of remnants can gradually accumulate and what’s left there and ignored can eventually go rancid. These remnants of decaying and stale coffee, mixing with your freshly made espresso, can cause a “dirty” taste to your coffee. As such, it is more important that grouphead flushing is regularly done.
N.B: Spring lever machines won’t have the same issue despite the huge amount of pre-infusion that it has, as it forces out most water and remnants during extraction.
The E61 grouphead circulates hot water from the boiler to stabilize its grouphead, this is called a thermo-siphon system. It can stabilize the temperature to match closer to the temperature of the water in the boiler, especially for single boilers or double boilers, not much help for heat exchangers. This feature does come with some disadvantages. The flip side is there’s a much higher chance of metal leaching into the water from the large amount of metal used in the E61 grouphead, especially with the continuous circulation of water around it.
N.B: Bezzera is a century old brand that is probably the most forward in the espresso machine industry for material engineering. One thing that consumers can’t observe just from looking at the specifications is they are using the most advance “no-lead” or extremely “low-lead” brass. Which are also additionally plated with a coating for extra protection. They are currently the best in this aspect among similar tier of espresso machines, weighing huge emphasis on product safety as well as on good engineering design. The reason why brass has remain to be the choice of metal is because of its inherent strength, durability and thermal conductivity.
Despite the reputation of the E61’s thermal stability, this stable condition will only be true if the machine idles for a long time. Else the displacement of water in the boiler, or using the steam wand can lead to a drop of temperature in the boiler followed by the grouphead. This explains why some E61 users felt frustrated with its temperamental stability. As such, E61s with heat exchanger boilers should use a much bigger boiler of at least 2 litres to reduce such displacement effects. Since it alway requires a larger boiler, and it requires the water to heat up, circulate around to warm up the huge chunk of metal in the grouphead. The start up time required is almost 70 percent longer compare to the BZ.
Both E61 and BZ are overall both considered reliable.
This is the exploded view of the E61 grouphead, which was invented in 1961, that is almost 60 years ago.
One thing to note about the E61 is despite the grouphead is solid with its huge mass of metal. There’s actually a lot of wear and tear happening in it, as the gears rub against each other during usage. As well as a lot of gaskets and lubrication applied in it that can go wrong over time. There are in total about 25 of such loose parts inside that can be worn. Normally a few worn parts might not cause any alarming issues, but they will have to be replaced sooner or later.
Now look at the BZ grouphead below which was invented only in the past few decades.
As you can see, the BZ is a much simplier design using two electrical components to replace dozens of loose parts to control the flow of water and heating of the grouphead. The amount of parts that can be worn, is now reduced to about 5 pieces, that’s almost an 80% reduction. Although it sounds like there are more electronics, but from our records, these two electronic components are pretty reliable and rarely fail. Also note that almost the entire grouphead(Part 38 to 43) can be removed for thorough cleaning. There is also very little space space for remnants to possibly retain. That is how it gets its “clean” taste with good clarity from all the coffee notes.
From our service records, the cost to service the E61 should be higher as it requires much more time and there’s also a higher chance of the components needing replacment.
E61s do have its advantages. As mentioned, the pre-infusion reduces the likelihood of channelling issue in the extraction, they are a little less picky on the grind setting. These two issues can be mitigrated by the user, by calibrating the grinder. In term of user-friendliness, we still think that the E61 might have a slight win over the other two systems. For users who love to fix their machines, the E61 has a lot of technical material found online for reference. It is also easier to find a technician to fix an E61, although it is actually easier to fix a BZ grouphead.
Are the material used in the machine safe??
Bezzera has their own factory to fabricate most parts of the machines, they craft their own boilers. As such, they have full control over the type of material used.
They are known to be the most forward in term of food material safety and had been using eco brass which has no lead or low lead. Brass has to be the preferred material for many parts of the machine due to its excellent heat conductivity, strength, corrosion resistance and natural anti-microbial properties. However brass is normally added with lead, else the material is very brittle making them hard to fabricate. Bezzera only use the highest quality brass that has insigificant amount of lead, almost considered no lead in the fittings and groupheads. All groupheads and most fittings are plated for extra protection, this means contact with lead is kept to the minimum. The newer models even have their solenoid switches, valves and pumps all made with the new material .
Most importantly, the boiler which has constant contact with hot pressurised water, is made of copper. Copper is an essential nutrient for the human body and the material has excellent anti microbial properties as well as one of the best thermal conductivity. Welding of parts are done with silver, which has no toxicity.
There are no toxic material, example aluminium, used in the machine.
Difference between boiler systems
Smaller boiler for low usage.
Unable to froth milk and brew at the same time.
They are not recommended for drinkers who prefer to do mostly milk recipes like lattes or cappuccinos.
More affordable for repairs.
A boiler in a boiler system.
Able to froth milk and brew at the same time
Strong steam power due to the single larger boiler.
Water used for espresso is always fresh.
Better clarity in espresso.
Good for making any recipes.
More affordable for repairs.
Two boilers, one for brewing and one for frothing milk.
Able to froth milk and brew at the same time.
More consistent temperature profile.
Good for any recipes.
More costly long-term repairs.
Heat exchanger should be the ideal choice for most users. Heat exchanger can froth milk and extract coffee at the same time and is a lot more reliable than double boiler. Double Boilers have a longer water network, and requires a lot more electronic and mechanical components to handle the two boilers. Heat exchangers only has one boiler and it has an inner compartment to form another “boiler” in it. Cost to service the machine for an heat exchanger should cost closer to a single boiler, with even better reliability.
Technically, the more complicated the machine, the more parts it has, the less reliable or durable it becomes.
The way the temperature descends as heat exchanger extracts, can be a positive thing, especially for dark roasts. It can reduce the astringents pulled at the end of the extraction. In any case, there’s no clear evidence of which boiler system can produce a better espresso but reliability and serviceability is something that everyone has to deal with.
Where to learn how to use the machine?
There’s no particular training required, but do note that spring piston espresso machines like the Bezzera Strega, will require some strength, height and physical capability to pull the lever down. It has to be handled with prudence to avoid injury and they are not suitable for petite users. Please follow the video guides closely on the Bezzera Strega product page before usage, particularly paying attention to how the handle can spring back without a loaded portafilter filled with sufficient coffee at the correct grind size to retain water in the chamber.
If you are going for a commercial or high traffic environment, you will require machines with rotary pumps which are rated for heavy duty usage, one exception is the Bezzera Strega TOP that doesn’t depend on the pump for extraction. For a huge traffic and think that one group is not sufficient, you can adopt having a couple of units and add-on modularly.