AndyS wrote:I agree 100%. Posters should feel free to report their experiences whether or not they are the result of a controlled experiment. As you correctly point out, this is not a peer-reviewed scientific journal.

But...whenever someone posts on a forum such as this, it is understood that other posters are free to comment, refute, argue, etc, in any fashion as long as the site guidelines for productive discussion are followed.*

And sometimes, some of us when it happens. I realise this is not productive, purely my own opinion.

AndyS wrote:Aside from the occasions when Dan Kehn magically pops up with a link, how does one normally find them?

It was my hope that members would rarely need them, so I intentionally omitted them from the posting window. So far that's worked out. In addition to Nicholas' observation about the guideline's location among the site information, an abridged version is part of the registration introduction (if you're curious, logout and click Register).

Compass Coffee wrote:I've sometimes wondered why they are sort of hidden in the News and Suggestions forum. Maybe they should be stickied in all forums, or pop up first 10 posts or something.

I like the idea about showing them for the first 10 posts. Enough to get the point across without treating new members like recalcitrant schoolchildren.

This thread is a little old, but I have some things to add because I have actually used this machine, which no one else in this thread can claim. The speculation and subsequent false assumptions are unfair, especially with regards to the claim that the machine does not offer true pressure profiling - hogwash.

The Slayer is equipped with a precision needle valve in the group that acts as a variable flow restrictor. Thus, not only the preinfusion time can be controlled, but the preinfusion pressure as well, in addition to being able to control the pressure throughout the entire brew cycle. I should mention that each group (which has its own boiler) has a very useful pressure gauge attached in plain sight, right next to the group. I should also add that the multigroup/multiboiler Slayer accomplishes its preinfusion and pressure profiling with the use of only one pump, which is a far, far more elegant approach compared to the Synesso.

With regards to workflow, how many of you have actually worked a busy bar before? There are plenty of things to be done in the in between times. Start preinfusing the shot on the group 1, unload and flush group 2, ramp up the pressure on the group 1, grind and dose the portafilter 2, kill the first shot, preinfuse group 2, unload and flush group 1. A good working barista is an octopus... one that pulls hundreds of shots within the course of a few hours, and within a small margin of error. Consequently, there is very little symmetry between a home barista and a working barista.

The photos online, which make it look cartoonish and slightly tacky, don't do it justice. In person, the Slayer is much, much more elegant than any photo can present it. On a machine that already announces itself, why destroy the thoughtful aesthetic balance with a garish logo? Not only does the machine look nice, it feels nice. The creators of the machine have obviously designed this machine with the barista in mind, because a lot of attention has been paid to the tactility of the machine - the acutator has the look and feel of a buck-knife, and the overall feel of the machine is surprisingly solid.. maybe surprising to me, at least, because I was expecting it to have the flimsy feeling of a Synesso. I understand that it's overall design is fairly simple, with easily accessible and easily serviceable components. Though I can't vouch for this myself, this is what the machine's owner has told me.

Last of all, the taste. For the record, the espresso I used was one that I have tasted and pulled a few times, but had never dialed in myself (friend's shop). The shots I had pulled on the Slayer had already been dialed on a Robur E. The shots I pulled varied from good to great, the only variant being how I profiled it. The profiling is definitely a really useful tool for fine tuning espresso. I have to say something about the mouthfeel... with a really delicate preinfusion, gentle ramp up to full pressure, then a slightly tapered finish (can't remember the hard numbers), the espresso felt like a cloud in my mouth. I know from tasting this espresso on a GS2, the Slayer had a very obvious contribution to this. I have heard from other firsthand users that the mouthfeel they often obtain is really fluffy and light.

All in all, I think the Slayer is outstanding. Time will tell how the machine will continue to perform and hold up, but so far, the Slayer fully delivers.

Hi,

so it has a needle valve inside the group to control the flow (I'm guessing it simply 'divides' the flow, some goes to the group and some to the drip tray, thus reducing pressure on the group, is this correct?) but I heard you have to stop the machine and disassemble the group in order to change the valve setting. If that's true and you can't do it during the extraction you're eventually stuck with two pressure levels that you can use, your normal in-line pressure and the group pressure, settable via the needle valve. This also means that you can't get any profile you like during the extraction, you can only switch between those two levels. Is that full pressure profiling? I don't think so.

A gauge near the group? what's new about that? probably more than 50% of machines have such a gauge, so I don't really understand where's the innovation here.

with a really delicate preinfusion, gentle ramp up to full pressure, then a slightly tapered finish (can't remember the hard numbers)

Now remember you get a lovely shot at the end of the day, you come back the next morning and you can't remember what profile you used. Pretty annoying I would say and easily fixable if you add a 'replay' function. Regarding workflow, some people that replied to this thread are actual baristas (not home ones) and agree that it might be hard to do the 'paddle' sequence the same way every time. And to be honest it's not even that, you usually have more than one person operating the machine and you can't assume they are going to profile the same way.

I agree that a single pump is better than 3 pumps and I agree the machine is looking very good, but I can't agree it offers full pressure profiling. That's of course is not saying that it's a crappy machine, far from it, it's probably the most interesting machine there is at the moment, perhaps until LM releases their truly fully profiling rig.

Regards,
dsc.

dsc wrote:so it has a needle valve inside the group to control the flow (I'm guessing it simply 'divides' the flow, some goes to the group and some to the drip tray, thus reducing pressure on the group....

Sounds like a bad guess to me. A needle valve is (generally) just a precise variable flow restriction, not a "Y" connection to divert a portion of the flow.

I don't understand the need to "attack" anytime someone posts a positive experience with this machine. The definition of "true pressure profiling" is subject to interpretation. Why get hung up over semantics? This machine offers some new capability over other available machines, that makes it an innovation in some way.

It does more than your post suggests because the preinfusion pressure can be adjusted rather than simply being open to line pressure, but it's still true that it has a 3 position switch (OFF - LO Pressure - HI Pressure).

What would be important to me is the result in the cup compared to other machines in this class.

I am not sure if one pump is more elegant solution than three pumps. I prefer more reliable setup with three backup-pumps
I like new trends in espresso machinery. But, a good and open-minded barista can make an outstanding espresso using an ordinary machine, e.g. LM Linea, FAEMA Legend... The outstanding espresso is not made by the cool machine but in the open mind of a barista. And this process is much more complex than a pressure or temperature...

Hi guys,

who's attacking anyone? I just wrote that I don't think it's true pressure profiling as you can't choose the profile you want whenever you want. If you think it is true pressure profiling, good for you, it's not like we have to agree on everything.

If it has a needle valve and it hasn't got a 3 way connection inside the group then I'm very curious how the needle valve affects the pressure. A flow restrictor won't affect the pressure on it's own as you already wrote.

It does more than your post suggests because the preinfusion pressure can be adjusted rather than simply being open to line pressure

Is this done via the same needle valve?

Regards,
dsc.

cpl593h wrote: I was expecting it to have the flimsy feeling of a Synesso.

It must be tough, as I basically dropped a 3 group Synesso Sabre off of the back of a truck without a hydraulic lift and it survived intact. From my perspective, it is truly built like a tank. Not to knock the Slayer at all, it looks very cool, but the Synesso is ANYTHING but flimsy.

dsc wrote:who's attacking anyone?

I would assert that our knowledge here is purely based on what we have read (since neither of us has experienced the machine in person). Your post seemed negatively directed so it occurred to me like a speculative "attack".

dsc wrote:I just wrote that I don't think it's true pressure profiling as you can't choose the profile you want whenever you want.

Again, "true pressure profiling" is subject to interpretation. To me it sounds like you are looking for computer-controlled (programmable) continuously variable pressure profiles. Apparently this machine only has the capability to manually alter the brewing pressure profiles by varying a set of given parameters.

The online information I've seen seems to clearly indicate that preinfusion pressure can be set at any value, so it's probably not just open to line pressure as it seems you may believe. But since I do not have any knowldge of how preinfusion pressure is varied I cannot answer your question.

dsc wrote:If it has a needle valve and it hasn't got a 3 way connection inside the group then I'm very curious how the needle valve affects the pressure. A flow restrictor won't affect the pressure on it's own as you already wrote.

It seems you have misinterpreted my words. You may want to brush up on how a valve can affect pressure and flow in a flowline (i.e. flow across a restriction creates a trade-off between pressure and velocity)

Hi Jon,

yes by true pressure profiling I mean a system which allows you to set the brew pressure to whatever you want at any given time, no matter if it's in idle state or during the extraction. To me pressure profiling means allowing to get whatever pressure profile you like. It can be fully manual, it's not a big deal, it doesn't have to be computer/uC controlled.

With the needle valve in place you get a pressure drop due to the lowered diameter of the pipe, but isn't that mostly in the section close to the actual orifice? I mean if you close the pipe at one end which you do by sticking coffee in the basket, water will flow through the orifice and eventually fill the whole pipe which means the pressure is going to be the same on both sides of the orifice. Or am I talking rubbish? feel free to correct me, but it seems like it's similar to a gicleur which does just that, lowers the flow and lowers the ramp up of pressure.

Again please notice that I'm not bashing the machine, I simply stated that it doesn't really give you the opportunity to brew at any profile and that is somewhat limited by it's manual operation.

Regards,
dsc.