Thread: Espresso Machine

That is just wrong wrong wrong.....why did I ever click on that link. I can't afford those beautiful machines and now I want one.....Gaaah


btw I love my coffee but may have to live with my Krips....for now

When I want expresso I just put two spoons of Tasters Choice in the cup instead of one.

bj

Ok, lunch break, time for a little more typing. I believe the last 3 posts hits on the major separation between machines with the exception of the lever based espresso machines so I will briefly get into some of the other considerations.

Let me start with groupheads. The grouphead is simply the head of the group, and the group is what the portafilter (that handle thing with the basket that you put your coffee into) locks into to brew your espresso. There are many different grouphead designs out there but the ones you will most likely see are the E-61 (originally designed by Faema in 1961), the E-61 like actively heated group, the direct connect group and the saturated group design.

The e61 group was the brainchild of the Faema corporation and has to be one of the most copied and widely used home groups on the market. The E-61 group uses a thermosiphon line to actively heat the group. The thermosiphon circulates water from the heat exchanger (in a heat exchanger machine) or the brew boiler (in a double boiler system) through two pipes. That water passes through a small expansion chamber in the group to keep that 8 pound hunk of brass hot. The cool water then circulates back into the heat exchanger.

The original E-61 group was lever activated and used a cam to open the expansion chamber and brew path while pressing on a micro switch to engage the brew pump. The expansion chamber takes a few seconds to fill giving the group a slow ramped pressure profile. The brew pressure is gentle increased over around 8 seconds from 0 to 130 psi. That gentle preinfusion tends to make the group easier to work with and more forgiving of any mistakes on the Baristas preparation of the portafilter. In addition to the lever actuated group, there are solenoid actuated groups. You push a brew button, a solenoid snaps shut closing off the 3-way pressure release valve (more on that later) and the extraction begins. Because the group uses a solenoid instead of a cam, that expansion chamber is not present, so the group pressurizes faster.

The E61 like groups vary substantially. Most have two things in common. A large hunk of brass that the water is passed through on its way to the portafilter and a thermosiphon to heat the group. The physical brew path and internal workings can be quite different than those of the E61 group even though they have a similar outward appearance.

The direct connect group appears on many of the smaller entry level machines. these groups are bolted directly to the boiler and pull their heat from the brew boiler via conduction. These work well in single boiler (or even double boiler) machines since the group will try to reach thermal equalibrieam with the brew boiler. So if your boiler is set for 203F, the group will try to maintain that same 203F temperature. It never does because heat is radiated out from the group. These groups normally need a warming flush to prepare them for use. The hot brew water will raise the temperature of the group and help stabilize the brew temperature.

Saturated groups are most often found on full commercial machines. A saturated group is hollow and directly attached to the brew boiler. The group itself is full of water, hence the term saturated. These tend to be very stable groups since they are part of the brew boiler system, not simply bolted onto the boiler. La Marzocco uses a saturated group, as do others. The brew path consists of a piece of copper tubing that that passes through the brew boiler and saturated group to the grouphead. That keeps the brew water at a very stable temperature. Some of these systems do use flowmeters and/or banjo tubes that exit the group prior to the grouphead which will affect the temperature stability, but that is beyond this post.

Each group has its pros and cons. The direct attached being one of the lesser stable, the E61 or thermosiphon heated group being the most common but prone to overheating which is partially why they need a cooling flush before brewing. Although a properly tuned thermosiphon line will minimize or even eliminate the overheat issue, but again that is a discussion for another time. The saturated groups are one of the most stable but are typically only found on very large machines since you need a big boiler to attach that hollow group to. What you will find on probably 90% of the home or home friendly machines on the market are E-61 or E-61 like groups.

Pumps. There are two types of pump systems (three if you count the lever based espresso machine), a vibratory and a rotary pump. The big separator between these two systems is the water delivery method. Most vibratory pumps draw water from a self contained water reservoir built into the machine while most rotary pumps require a direct plumb connection. There are exceptions, but 99% of them will follow this configuration.

Vibratory pumps are small and cheep in cost. They will easily fit inboard on an espresso machine. The down side, they are noisy. As the name suggests they vibrate. Think of a car piston but it is pumping water instead of fuel/air. That high speed back and forth pumping action creates a buzz as they run. There are two standard wattage pumps on the market but most machines use the 41W pump. A vibe pump also needs an external pressure regulator, or over pressure valve (OPV). Many of these pumps will generate 12+ bars of pressure. Since you want somewhere between 8 and 9 bars of pressure for the extraction, there is an overpressure valve between the pump and boiler. Most of them are spring loaded ball valves. You adjust the brew pressure by adjusting the spring tension. At a predefined pressure, the spring compresses, the valve opens and the excess pressure is vented back to the water reservoir or drip tray.

Rotary pumps are much larger. They use a 110/220 volt pump, usually ¼ to ½ horsepower for the pump motor. The pump itself then attaches to the motor shaft. Some machine outboard the rotary pump, others will have it onboard. The tradeoff, you have to increase the footprint of the machine to hold the large pump. These pumps use a different pressure regulation system and the adjustment is made directly on the pump head. Everything is compact and convent as well as easy to adjust which is what you want in a commercial environment. They are also whisper quiet.

Most rotary pumps are direct plumbed. As a result, you need a dedicated plumbing line run to the machine. They are also very susceptible to static line pressure. If you’re ambient water pressure fluxes, your brew pressure will wander. That is something you do not want. You will need a pressure regulator on the supply line to cut the mains pressure down to what the machine requires. In areas of pressure flux, an accumulator tank can be added to further stabilize the pressure. Rotary pumps can be used from a static water reservoir like a 5 gallon water bottle provided the lift distance is very short. If it is any longer than a couple of feet, a flowjet may be needed to provided a positive boost as well as an accumulator tank for added pressure stability.

The big plus to a rotary is longevity and duty cycle. They take a lot to wear out. Their quite operation is nice and the direct connected plumbing requires no attention beyond the initial installation. The down side, they take dedicated plumbing and you will need to cut holes in your countertop to run the supply lines through. The machines with onboard pumps also tend to get quite large and heavy.

Under $1,000.00 the most popular and probably the best espresso coffee machine is the Rancilio Silvia. I got one I am extremely happy with it.

You can read the reviews on www.coffeegeek.com

have fun

Norm.

Wow thanks for all the info I have lots of reading to do. Thanks you all for the help I will let you know what I get.

Some solid options,

Vibiemme Domobar Super, did a buyers guide on this one, then got one. Solid machine.

Almost any Elektra, I have used all 3 of these, super nice machines.

Elektra Micro Casa A Leva Lever

jElektra Micro Casa Semiautomatica

Elektra Sixties Model A3 and T1 single group commercial machines are near and dear to me. I have one so I may be a bit biased but you just can’t beat it without jumping to an $8000 and up machine.

La Cimbali Junior DT1 is another solid lifetime machine.

Ponte Vecchio Lusso Lever

La Spaziale Vivaldi II and its little brother the Mini Vivaldi II are good entry level double boiler machines.

The Andreja Premium, Anita and the Vetrano are good solid machines.

Or you could shoot the moon and get the new La Marzocco GS3. Another lifetime espresso machine.

Mazzer Grinder, I prefer the Super Jolly or Robur over the Mini but the Mini does a good job.

MACAP Grinders also do a good job but I prefer the Mazzer for build. But the MXKC10 is better than the M4 series because of the conical burrs.

Mahlkonig grinders are good as well. I am seeing more of the K30 in the wild. If you really wanted to go absolutely nuts you could get a VTA 6S commercial. It grinds a pound of coffee in 10 seconds, a little overkill when a double shot uses 14-18 grams of coffee.

My personal preference, La Cimbali Max. Chris sells a Cimbali Jr/Max hybrid. The Max burrs in the kitchen friendly Jr case. I have the full on Cimbali Max grinder (2 of the actually and a Jr).

Keep in mind, the best espresso machine on the planet will only make tar if you don’t have a good grinder and freshly roasted beans. By freshly roasted, no older than 14 days out of the roaster. Most coffee goes flat after 8 days and don’t even try pre-ground. Ground coffee has a life expectancy of 30 seconds.

Hopefully I have not created more confusion. I would be happy to answer any questions and if you want to play with a machine I have one or two you could work on at my house. I will even make you a deal on a two group Faema 220v machine, have one sitting downstairs that I frame up restored.



Edit: avoid the super automatic machines. The push one button and it grinds, brews and froths for you. They make something that resembles espresso, but you will get a much better shot from a real espresso machine.

Dave....... Urgl..... You.... are... not....helping......

Regards

Kaptain "Now staring down a set of shotgun barrels held by my wife" Zero

Life is too short to drink cheep booze, eat bad food and mediocre coffee. Guess I would have to add shave with cheep razors to that list now as well.

I'd have to agree that life it too short to drink bad coffee.... after all, there's plenty of time to sleep after your dead. I just wish the latter part wasn't so threatening when I started looked at espresso gear on the computer!

I did manage to sneak in a Maestro grinder... ok, not so much sneak as in "honey, can you taste a difference in the coffee, NOW?" Which of course blew her away, but not, unfortunately, out of the reach of that damn double barrel job. I might convince her to go for a Technivorm when the current Braun drip machine dies but a shiny new espresso machine..... I don't think so. If she did, I'd be all over the La Spaziale Vivaldi and a decent grinder. I'd have to go for the plumbed in model though.... But then again, as mentioned earlier... I'd probably develop an acute 12 gauge leak of important body fluids if I spent that kind of money on coffee.....<sigh>.

Regards

Kaptain "But...but...but.... all my friends have one of these, why can't I ?!?!?" Zero

Well Dave, having followed this and other similar threads I can tell you one thing. It's a good thing I don't like coffee.

Take it easy on Don, he has one of the lowest resistance levels to ADs I've ever seen. Poor guy just spent $5K and doesn't even know it.

Let's go shooting.