Semi-Automatic Pump Espresso Machines
Buyers Guide

With so many semi-automatic models to choose from, figuring out the right one for you can be confusing. There are a few different options, capacities and components available that will factor into the decision of which machine is best for your needs.

Here is a brief lesson on what's involved with operating a semi-automatic.

1. Turn on the machine and, with the portafilter securely in place, allow it to heat up for at least 20 minutes.

2. Grind your coffee beans to the amount (dose) that you want into the portafilter if you are grinding it yourself.  Otherwise, measure out into the portafilter the pre-ground that you have purchased.

3. Level the grounds in the portafilter and apply pressure with a tamper to create an even seal and suitable resistance for the water.

4. Start the pump and watch as the water flows through the coffee and into your cup.  You will immediately start to see the effects of your grind, dose, and tamp and you will know if you made an error somewhere in the process.  If all looks good, keep the water flowing until you have as much as you need.

5. Shut off the pump when there is enough espresso in your cup.  It should have taken 20 to 25 seconds for a double shot to pull through (14g of coffee and 2 to 2.5oz of water).  If any of these numbers are off, you will have to figure out why and adjust accordingly for the next shot.

6. Remove the portafilter and bang out the used grinds.  Rinse it well and dry it before hanging it back into the grouphead or making another shot.

The variables:

   1. Grind - the coarser the grind, the faster the espresso will pour out.  If it's too coarse you will have a very weak, under-extracted shot with little or no crema.  A finer grind will offer more resistance to the flow of water and so the espresso will come out more slowly and therefore take more flavour and aroma out with it (longer contact time between water and ground coffee means stronger espresso).  However, if the grind is too fine it is possible to over-extract the espresso, making it bitter.  Note that different beans will need different grinds so if you switch your brand suddenly, you will have to change your grind too (and/or your tamp).  Typically, darker roasts should be ground coarser than lighter roasts. And remember, fresh ground is always better than store-bought pre-ground coffee.

   2. Tamp - your tamp pressure works together with the grind to create the proper resistance in the puck.  A strong tamp can compensate for a coarser grind by packing the coarse grinds well enough that there is little space free between the coffee particles.  A finer grind can compensate for a weaker tamp. 

   3. Dose - The amount of coffee you pack into the portafilter also makes a difference on extraction rates.  Even a slight amount too much or too little can change the time of brewing by several seconds (more coffee means it takes longer to force the water through).  Also, coffee will expand as it brews and if you put too much into the portafilter, it will not have room to expand enough and can cause a loss of crema as well as a bitterness to the taste.  You will want to measure it 2-3mm below contact with the screen inside the grouphead.  Try packing a shot and hooking the portafilter into the grouphead and then remove it again without brewing the shot.  Do you see an indentation of the showerscreen in the grounds?  You've overdosed.

  Basically, the formula is grind + tamp + dose = 20 to 25 seconds and 2 to 2.5oz.  There is no set value for grind, dose or tamp as long as together they create the desired result.  This is why it takes some time to master brewing shots on this type of machine.  It is an art as much as a science and there will be some trial and error involved.  You will want to keep your dose consistent with every shot and you will find that you have a tamping force that comes most naturally to you.  Therefore, if anything needs to be changed, we would suggest starting with the grind so that you will have a consistent tamp that you will become used to. 

  We are often asked, "Which is the best machine?" and the only real answer that can be given to that is, "For what?".  There is no 'best' machine.  Some machines are better at certain things than others and some are just easier to use for some people, but harder to use for others.  There is only the best machine for you.  It's different for everyone.  That is why we have provided the following list of options.  Please think about how you want to use the machine based on the following items.  Make a list of the features that sound useful to you and of the ones that you absolutely must have.  This will help you to narrow down your choices.  See our Feature Comparison Search to find out which machines have all the features you're looking for.

Pressurized Portafilter

Pressurized portafilters are the easiest way to make a good espresso with crema (the foam on top).  They have built-in pressure so that you do not need to tamp (in fact, you shouldn't tamp because you can easily create too much pressure).  Purists will typically not use these as they want to be responsible for the end result but for many people, a little bit of cheating is not such a sin.  If you want to upgrade, you can often buy a non-pressurized portafilter to replace the pressurized one.

Steam Feature

If you plan to use the steam feature frequently to steam up milk for cappuccinos, lattes or hot chocolate, consider the delay time between brewing espresso and steaming milk. Most single heating system versions experience a delay time of up to one minute before you can start steaming milk. When switching back from steaming to brewing, some models need to be flushed first before you can make another espresso. You may want to look at dual heating system versions or rapid steam features. This will reduce or eliminate the delay time.

Some different styles of steaming:

Steam Wand - As pictured above, it's a piece that is attached to the machine and releases steam from the tip.  Put milk into a frothing pitcher and steam it manually with this device.  It takes some practice to get proficient with it, but you will have more control over the temperature and the quality of the foam with this method.

Automatic Frothing Devices - Usually a device that connects to the machine where the steam wand would be and has a tube protruding from it.  You put the end of the tube into any container of milk (some machines come with a milk holding container) and, when you turn it on, the milk will be sucked through the tube and foamed inside the attachment before falling through a spout in the attachment into your cup.  This method is very easy to use, but the milk temperature tends to be lower and it is more difficult to customize the ratio of foam and steamed milk to your liking. There is also more cleaning involved with this method.

Pod Adaptable

Portafilter Options

Boilers Vs. Heat Exchangers

There are two different styles of heating systems - boiler and heat exchangers.  A boiler is a vessel inside the machine that holds and heats the water.  A heat exchanger is an element that quickly heats the water as it passes through from the reservoir to the group head.  Boilers have greater temperature stability and are commonly used in the higher-end machines.  Heat exchangers are commonly used on less expensive machines and it is particularly important to run plenty of water through them before brewing your first shot to make sure that all the parts are heated up properly or they will draw some of the heat back out of the water while you are brewing.  Boilers are commonly made of a material like brass, which holds the heat well, and heat exchangers are often made from aluminium or sometimes stainless steel.  Some machines will have dual heating systems, either in the form of a double boiler, a double heat exchanger or a boiler and a heat exchanger together.  These systems reduce or eliminate the waiting time between brewing coffee and steaming milk (the temperature for steam is higher than the temperature for coffee so single heating systems have to keep switching back and forth).  Some at the higher levels can even allow you to brew and steam simultaneously.  Generally speaking, a machine with a boiler for the coffee and a heat exchanger or second boiler for steam is better than a single heat exchanger unit, but they will also cost you more (usually much more).  On single heating systems, you will also have to remember to draw water through the machine after steaming or wait several minutes for the temperature to drop down again to be able to brew espresso.  Too-high temperatures will negatively affect the espresso quality. 

As a side note, many manufacturers confusingly refer to all heating systems as boilers but in reality you will only get true boilers starting about the middle of the price ranges so don't expect one in the cheapest model you can find.

Controls and Displays

The controls are often either a button or a rocker switch which is really just a personal preference.  The steam may be controlled by an on/off type control or with a dial that allows you to control the amount of steam produced, which is definitely better for controlling the foam quality (and really required if you're after microfoam).

Type of Pump

Most commercial machines use rotary pumps and most home use machines use vibratory pumps.  Generally, rotary pumps are quieter and work in combination with plumbed-in machines while vibratory pumps do make some noise while heating or brewing and are typically used with water tank machines.  It has been said that rotary pumps also produce a smoother crema with less bite.  There does not seem to be any consensus as to which type is better and unless you're ready to move into the semi-pro arena, you're probably going to end up with a vibratory pump.