Evening all. I just finished wiring in a time adjustable (0-10 second) delay on make relay. I have adjusted my line pressure up to 3.5 bar on the machine, 4.5 bar at the regulator in the basement. I have spent the evening getting the timing set. I am running a 4.5 second delay which saturates the puck to the base.

My very preliminary results, it appears to have smoothen out the cup. Less harsh, softer taste in the cup. The extractions have also become, for lack of a better term, prettier. Smoother starting and more even.

So a question for those of you with similar setups, are your observations the same and how do you time your shots? Do you start your shot timing at the beginning of the pre infuse cycle or after the pump engages?

cannonfodder wrote:Evening all. I just finished wiring in a time adjustable (0-10 second) delay on make relay. I have adjusted my line pressure up to 3.5 bar on the machine, 4.5 bar at the regulator in the basement. I have spent the evening getting the timing set. I am running a 4.5 second delay which saturates the puck to the base.

My very preliminary results, it appears to have smoothen out the cup. Less harsh, softer taste in the cup. The extractions have also become, for lack of a better term, prettier. Smoother starting and more even.

Your preliminary results make sense: if you get a more even preinfusion, you will generally get a more even extraction with fewer harsh, overextracted flavors.

I've been experimenting over the last week or two with the pump-pulse pre-infusion that my Expobar is capable of (since I got a new control panel last year). I'll be posting more about my results in a week or two, but to answer your question about timing: I've been timing from the moment the pump enganges after the pre-infusion.

YMMV.

cannonfodder wrote:Evening all. I just finished wiring in a time adjustable (0-10 second) delay on make relay. I have adjusted my line pressure up to 3.5 bar on the machine, 4.5 bar at the regulator in the basement. I have spent the evening getting the timing set. I am running a 4.5 second delay which saturates the puck to the base.

My very preliminary results, it appears to have smoothen out the cup. Less harsh, softer taste in the cup. The extractions have also become, for lack of a better term, prettier. Smoother starting and more even.

So a question for those of you with similar setups, are your observations the same and how do you time your shots? Do you start your shot timing at the beginning of the pre infuse cycle or after the pump engages?

The addition of preinfusion has not caused me to change my shot timing. I still shoot for around 30 seconds beginning with the initiation of the shot (with the 6 seconds of PI counted) but in reality have a range of around 25 to 35 seconds for a double shot which in my hands averages around 1.25oz.

ken
p.s. I don't know if it smoothens the cup but it does reduce the percentage of channeled and sink shots.

Thanks for the information. These are my very first prelim observations, a whole 4 shots. It will be interesting to see how things develop over the next couple of weeks.

I home roast most of my coffee, and the results may just be the variation in my amateur HotTop roast. I will have to order a pound of coffee that I am familiar with to see if the improved cup translates to a professional roaster.

Has anyone noticed a change in the pre-infusion time between coffees? I have the timer under the drip tray so you would not notice it unless you were looking, but it is easily adjusted from the front of the machine. Is this a one setting works for all, or are the differences from coffee to coffee so minor it would be counter productive to fiddle with it?

For clarification, I am actually running 4 bar pre-infuse pressure at 4.5 seconds. I get a saturated puck but no coffee is emerging from the basket until the pump engages.

cannonfodder wrote:Thanks for the information. These are my very first prelim observations, a whole 4 shots. It will be interesting to see how things develop over the next couple of weeks.

I home roast most of my coffee, and the results may just be the variation in my amateur HotTop roast. I will have to order a pound of coffee that I am familiar with to see if the improved cup translates to a professional roaster.

Has anyone noticed a change in the pre-infusion time between coffees? I have the timer under the drip tray so you would not notice it unless you were looking, but it is easily adjusted from the front of the machine. Is this a one setting works for all, or are the differences from coffee to coffee so minor it would be counter productive to fiddle with it?

For clarification, I am actually running 4 bar pre-infuse pressure at 4.5 seconds. I get a saturated puck but no coffee is emerging from the basket until the pump engages.

Obviously I don't know the answer to this question, but I doubt that you could ever figure it out with one set of taste buds and whatever your toleration is for caffeine. Your 4.5 seconds at 4 bar is probably more or less the same as my 6 seconds at 3.0-3.5 bar (it seems to vary a little when I measure it).

Getting back to your original question, I think you have to decide how to deal with what the preinfusion "does," and also to realize that the timer is not the be all and end all of shot quality; it is just a guide. In my experience with 3.0-3.5 bar preinfusion, when the pump kicks in the coffee really starts to flow out of the bottomless PF, unless I have ground too finely. Without pre infusion, it still takes several seconds before I see the first few drops unless the shot is severely channeled. So, because I observe a real difference in the puck with preinfusion vs. no preinfusion, I count the preinfusion time because something is obviously going on that effects the remainder of the shot.

But all of this is of questionable utility if you are doing what you should be doing, which is watching the shot as it pours, and cutting the shot when it starts to lighten. Since I count the time of PI, I am grinding in a way that gives me a lightening of the shot at around 30 seconds, seldom earlier, since that is my benchmark and I prefer shots that exceed 30 seconds to shots that are appreciably shorter. Assuming you use a bottomless PF, the shot is going to lighten a second or two earlier than with a spouted PF, and I use a bottomless. So, if I cut the shot at 35 seconds from the start of PI, that is a 35 second shot or that is a 29 second shot, take your pick. If I cut it at 40 seconds, then it is a 40 or a 34 second shot. If I cut it at 30 seconds, it is a 24 or a 30 second shot. But if I cut it at less then 26 seconds, it could be a 20 second shot which without PI would probably not be very good, but with PI it might be.

Come to think of it, how you tamp and how you dose will also effect this; I updose 18g into my doubles that are supposed to hold 16g; undoubtedly that effects extraction times as well. Unless your techinique is the same as everybody else's (and I'm not sure what that technique might be) then you are stuck with having to find your own way, and no one else can help you to find what works best with the way you do things.

In the end I'd go more on how the shot looks as it pours than what the timer says. The purpose of the shot timer, in my hands, is to stop my sense of time from drifting over time and getting to the point where I think a 15 second shot is ok.

ken

Ken Fox wrote:... you are stuck with having to find your own way, and no one else can help you to find what works best with the way you do things.
ken

And the journey continues anew.

I use a timer with espresso in the same fashion I use a thermometer in milk. More of an occasional reality check than a firm guideline as well as a consistency check. If my shots fall within a second or two of each other then I have some semblance of consistency. I actually don't have a timer on or beside the machine. When I do want to check, I just use the second hand on my watch.

So after all is said and done, we are back to the most basic of basic. Let the cup be your guide.