The Delter company is Australian, and founded by Mark Folker , who has previously, designed another pressurized brewer : the Trinity One brewer. If you look carefully, you can see that the logos of the two devices are quite similar.
The company claims that the primary purpose of the brewer is ‘to solve one of the biggest brewing challenges – uncontrolled agitation.’
When you first look at Delter Press, it pretty much looks like a transparent version of the Aeropress. Because it has the same chamber and plunger, and you insert a paper filter in a lid and screws it on. But there are some differences that declare it a different product.
The plunger is not just a plunger. It’s designed in a way that has taken quite a while to get right. It has a few small holes in the bottom, just above the rubber seal, and when you lift the piston a bit water is allowed to flow into the main body.
When you then press down again, water is forced through the brew chamber. In that sense, the plunger has an interesting double-function. There are volumetric markings on the main body, so you can control precisely how much water you push through with each plunge.
With the Delter Coffee Press, the coffee grounds are put in a separate chamber. The two compartments are separated by what the company calls a jet seal.
The idea is that this rubber piece forms a close seal when there’s no pressure. However, when you press the piston, water goes through the membrane. This is an attractive solution. I’m not sure I have seen that same idea being used anywhere else in coffee.
The Delter Coffee Press relies on percolaton, since water is only in contact with the grounds for a short period before going into the cup. This extraction method has a unique impact on the flavor, texture, mouthfeel and acidity.