Hydro-pressure coffee makers, or steam coffee makers, are coffee machines used to make espresso coffee. But through a more straightforward and less expensive system than the traditional espresso machines (with pressure pump) that we all know. Following we will describe in more detail how steam-pressurized coffee machines work.
In the segment of hydro-pressure coffee machines (or semi-espresso coffee machines), some well-known models compete in popularity and market share with the large espresso machines. Some examples are the Delonghi EC7 hydro pressure coffee maker or the Jata CA704 hydro pressure coffee maker.
These pressure brewers produce coffee of enough quality for many users and are more practical because they are smaller in size and more affordable in price than pump brewers.
They are quite popular on the Internet, but it must be made clear that they are not used to obtain an authentic espresso, such as Italian espresso.
Let’s get to understand them a little better:
What are hydro-pressure coffee machines?
Hydro-pressure coffee machines are coffee machines with a clear domestic orientation, designed for lovers of instant and soft espresso coffee. At the time, they were a small revolution because they allowed coffee to be brewed in very few seconds (drip coffee machines, for example, take several minutes).
It must be made clear that these coffee machines make an espresso (although with some peculiarities, as we will see below), which means that the grinding and the qualities of the bean must be adjusted to this extraction method, as if we were using a manual espresso machine.
However, in some coffee machines, it is recommended to use a medium grind -not as fine as the specific one for espresso- to facilitate the passage of the water through the filter, since the water circulates through the filter at a much slower speed.
You can learn more about grinding thicknesses by reading this article: One Type of Grind For Each Coffee maker.
Hydro-pressure coffeemakers often include accessories and elements that are specific to espresso machines, such as the vaporizer tube or options for determining the intensity of the coffee (mild or intense). They are speedy and have a minimal size, perfect for small kitchens.
And both are handled in a very similar way: they have a filter holder with a handle and a filter where we deposit the ground coffee. The water circulates through the filter – not driven by a pump, therefore at much less speed than in an espresso machine – and produces a coffee with a more full-body, with the shades less concentrated than in regular espresso.
Coffee extraction: Pressure and results
Hydro-pressure coffeemakers differ from conventional espresso coffee makers in that the latter use a pressure pump, which is capable of pumping water at a higher pressure (usually 15 bars, although some reach 19 bars).
In steam-pressurized coffee machines, this pressure is marked by the flow of the water itself, and not by a pump that drives it. This pressure, as is natural, is much lower than in espresso machines. For this reason, hydro-pressure coffeemakers are also known as semi-espresso coffee makers.
Does this mean that the coffee in hydro-pressure machines is worse than that in espresso machines? No. It is merely different, as it is extracted under less pressure. But it is neither better nor worse. This last judgment must be determined by your palate.
However, keep in mind that an authentic espresso (which is always extracted at 9 bars) can only be obtained with a manual espresso machine, of the pump type. Hydro-pressure coffee machines can never reach these 9 bars.
For more information about pressure bars and their effects on coffee, we recommend that you read the following article: What are pressure bars for?
How does a hydro pressure coffee maker work?
During much of the process, hydro-pressure and espresso coffee makers share performance and qualities.
The preparation is the same in both types of coffee machine: we serve the ground coffee in the filter, we press it -never in excess-, we place the filter in the dispenser, and we turn it to block it.
Then we start the brewer, and this is where the hydro-pressure brewers behave differently.
As you know, to extract a good espresso, the water must pass through the ground coffee filter with a determinate pressure.
In manual (pump) espresso machines, this pressure is achieved with a pump that can drive the water with a pressure of up to 15 bars. The water is heated only to the ideal temperature for espresso (between 90º C and 95º C) and is driven by the pump through the filter.
In hydro-pressure coffee machines, the water is heated to steam (about 130º C). This steam is responsible for forcing through the coffee filter (steam pressure), although with a much lower pressure than in espresso machines.
It’s a much simpler and cheaper method than the espresso pump coffee machines, and that is why hydro pressure coffee machines are often marketed as a low-cost solution. It does not indicate, by any means, that the coffee they produce is worse than that of other methods. Just be aware that coffee is extracted at a lower pressure than traditional espresso, and therefore will have different qualities.
In this video, you can see entirely how an espresso machine works with steam pressure (or hydro pressure):
Which is the best hydro pressure coffee maker of 2021?
That one is an impossible question to answer in this segment. As we have already said, on the Internet there is a relatively scarce supply of this type of machine (let’s put a figure between 15 and 20 models of different brands on sale, no more), but they are all very similar to each other.
The essential characteristics of hydro-pressure coffee machines are common and are repeated almost invariably:
- Water tank and 0.35-litre glass jar (about 4 cups of coffee with each brewing).
- Power 800 watts.
- 3.5 bar pressure (there are a few models with 5 bar, but nothing more).
- Price around 40 or 50 £.
So, the best hydro pressure coffee maker will ultimately be the one that has the best offer at the time you go to buy it, or the one that comes from a manufacturer that you trust enough.
Hydro pressure coffee makers vs espresso coffee makers
The following is a review of the main differences between a hydro-pressure coffee maker and a manual espresso coffee maker.
- In hydro-pressure coffee machines, the pressure required to extract an espresso is obtained employing steam. In espresso machines, this is achieved by means of a pressure pump.
- Hydro-pressure coffee machines have a maximum pressure of 3.5 or 4 bar. The pumped espresso machines reach up to 15 or 19 bar.
- Hydro-pressure coffee machines are generally considerably cheaper and smaller than pumped espresso machines.
- They tend to have a smaller size than espresso machines, around 250 or 300 millilitres. The espresso machines can assemble deposits of more than one litre of magnitude, since in each extraction only the just and necessary water is used for a dose. The remaining water is stored in the tank for the next removal. In hydro-pressure coffee machines, all the water is consumed in each extraction, so they have smaller containers that hold 2-4 cups of coffee at most. In this sense, their operation is similar to that of drip coffee machines.
- In hydro-pressure coffee machines, the coffee is extracted into a glass jar, while in pump express coffee machines the coffee is produced in individual doses and served directly into the cup.
- They only incorporate one filter for the filter holder. It is not necessary to have two different sizes, as is the case with espresso machines.
- As the pressure is much lower, no cream is produced, or at least not as dense as those of the pumped espresso machines.
- Almost all the hydro pressure coffee machines on the market have 800 watts of power.
- There are not many different models of steam pressure machines on the market.