The difference between a compact and a normal size espresso coffee machine
Is the boiler size different?
A compact espresso machine usually has a 5 litre compared to a 10 litre boiler. This boiler is placed often vertically inside the machine giving the compact espresso machine a much smaller footprint. The width of a La Spaziale 2 group espresso machine is 77cm compared to a Compact which is only 58cm for example.
This different size boiler has some great advantages such as a small footprint and less power consumption but it also gives you some things to think about.
Does a compact use less power?
Yes, because a compact has a smaller boiler it often uses a lot less power. Most compact espresso machine can run of a standard 13amps power plug, this is because they maximum use 3000w. 3000w / 240v is 12,5 amps so a 13amps single phase power supply is fine. In other words, just a standard power supply.
This is great for the environment which is something we should all think about. But who knows, in the future we can probably run an espresso machine of water power alone! (more on that in 5 years)
Can a compact handle busy queues?
Yes, no problem at all. This might surprise you! Although it does depend on what you use it for...
As you now know the main difference is the smaller boiler. Because you have a smaller boiler you also have less storage for steam. If you use your compact machine for lots of hot water and you steam for very large cups then it might struggle. If however, your cups are not super big and you don't draw hot water from the machine then it will handle busy times just fine. You could make coffee just as quick on a compact as on a normal size machine.
When it comes to making more coffees at the same time, it is the amount of groups that make the difference. A 3 group can handle more coffees then a 2 group at the same time. But is not necessarily true that a normal size 2 group can handle more coffees at the same time then a compact 2 group.
Every time you draw hot water from your boiler your steam pressure will drop. This is because you increase the space for steam; more space with the same amount of steam means less pressure. The boiler will also fill again with cold water which will cool down your boiler water. If you take out too much hot water, let's say two big pots of tea, then the steam pressure can drop below 0.5 bar and your boiler will fill with a large amount of cold water. This is not really a problem if you give the machine time to come back to temperature. If however you you don't give the machine time to recover then your coffee will not be as good as it is made with too low temperature and you might struggle steaming your milk as you have no pressure.
A compact machine is often controlled by a pressure stat and not a thermostat. Some normal sized espresso machines use both and are therefore very accurate in controlling the temperature. A pressure stat basically means that it will try to regulate the temperature by measuring the pressure inside the boiler. A thermostat accurately measures the temperature. Temperature control is very important as a variation in brewing temperature will cause variations in the flavour of your shots.
You should note though that the brewing water is not coming from your boiler.