yakster wrote:Only if you ignore the video's instructions to "gently press piston."

One could add this to the Worlds Strongest Man TV or Cable program (or whatever this excuse for entertainment is called).

Magnus magnusson, Samuel Samuelson and Fergus Henderson (or whatever names these telephone pole flippers go by today) try to make more crema.

Dan can judge.

BTW - for some more physics Boyle's law makes it clear why manometers in espresso machines are connected to the boilers by capillary copper tubes and not regular 6mm copper tubes.

Obviously for the same reason air needs a longer piston (discussed extensively above). Air compresses. But if the tube is very narrow the volume of air in the tube is also tiny. Boyle's Law would then mean that to get the 9 bar one would need to give up very little liquid for compliance.

BTW - AS far as I remember Boyle's law only accurate in Isothermal conditions. k=nRT. The two first are constants. But T is only constant if you can maintain temperature constant. But I do believe it is close enough and does a good job in explaining why you need to push more volume in the presence of air. And why it so important to bleed hydraulic lines like brake lines.

Thanks to all for debating Cafflano® Kompresso. There are two major factors we used in the development. One is hydraulics to amplify the force (actually transforming the energy form) and the other is squeezing force which is at least 50% more powerful than just pressing.

The energy loss from air-layer is for sure as air can be compressed but it's minor compared to the hydraulic compression and squeezing force. The air-layer (buffering effect) helps espresso being extracted with just one press (squeeze).

As we achieve enough force to make over 9 bar from hydraulics (Pascal's Principle) and squeezing handles, there might be questioning of how to control over extraction in case more than 9 bar. The answer is the taste after espresso extraction. Then we have to check the extraction time (25-30 seconds) while you fully squeeze and try to find out the sweet spot with espresso grind size, strength of tamping, hot water temp., etc... Of couse the best thing is to find the quality espresso beans. This is not a pain but enjoyable fact to make your own perfect espresso.

We currently have no commercial version as usual for Kickstarter and scheduled the productional version in late July/early August. So we used only design mock-up which is relatively weaker than our target (production model). The creama is a good barometer but not always as it depends on too many factors. Some beans do not make a lot of crema but perfect espresso can be extracted. The environment to have made video clips with design mock-up for Kickstarter campaign was very harsh and we needed to mix the clips taken in/out-doors.

Cafflano® Kompresso is not a commercial espresso machine in shops but the best cost vs performance we guarantee. Of couse it is the most hygienic machine you don't have to pre-wash with hot water once or twice before you put espresso ground coffee like other machines as it is so easy to clean and dry. This is how we received the 'Best New Product Award' from SCA World of Coffee Budapest 2017 and qualified the authentic espresso from baristas/roasters who have tried with only design mock-up.

Best regards,
Cafflano One Team

Good luck to you and the team.

It may indeed find a fit in todays "flow profiling" fashion which result in low pressure extraction. The 8-9 bar number we all throw around is a general number, but with flow control delivering something (we have yet to know what that "something" is) - it may be in for a fight.

Thanks! Cafflano Kompresso is the third flagship product from us following Cafflano Klassic (all-in-one pour-over coffee maker) & Cafflano Kompact (simplenpressing got & cold brewer). Compared to air-pump type, Kompresso can make authentic espresso with consistent high-pressure. As we implemented squeezing handles on top of hydraulic compression (like a car brake system), we can generate over 70~80kgf if we squeeze both pulling and pressing handles of Kompresso on the table. This force is much higher than required force 54kgf for the piston-chamber area 6cm2. This is how we can ignore the energy loss from the compression of air-layer and the friction between silicon gasket & cylinder chamber. If we had no confidence of this new project, we wouldn't have thought about Kickstarter campaign as we are now coming back there the third time. Hope you trust what we invented and watch out the commercial version which comes out in August!

Best regards,
Cafflano One Team