Cheers, Allen. I've been the beneficiary of lots of good info on this list... bmc On Mar 3, 2011, at 4:10 PM, Allen Worrall wrote:
> Thanks Ben for this very helpful discussion. You have enhanced my > understanding of espresso brewing by a great deal. > > Allen > > -----Original Message----- From: Benjamin McCafferty > Sent: Thursday, March 03, 2011 12:29 PM > To: [email protected] > Subject: Re: Newbie Question #2 > > Hi Allen (and Pete, some more thoughts for you), > > I suppose you have a point there, so I broke out the calipers and did some > measuring. I measured the difference between the bottom of the PF ears at > its thickest (fully engaged) and halfway across the ear (halfway engaged). I > don't consider less-than-halfway-engaged to be very safe, so didn't measure > that. > > The casting is not precise, so the differential was anywhere from .2 mm to .5 > mm between those two points. Taking the worst case, that would mean the puck > was .5 mm closer at full lock than at half lock (6 o'clock vs. 7 o' clock). > For reference, a dime is measuring at 1.3 mm thick, so this is a bit more > than 1/3 of that thickness. > > Personally, I doubt this makes a ton of difference, as long as you have a > reasonable grind/dose/tamp to begin with. That said, many of us have used > the "dime test" in the past--grind/dose/tamp as usual, then place a dime in > the center of the puck. Load the PF into the group, then carefully remove it > again. Ideally, the dime will be lightly dented into the coffee, but not > submerged below the surface, if that makes sense. So referencing the numbers > above, if the dime is barely denting vs. halfway into the puck, I doubt you'd > be able to taste a ton of difference, but probably someone on this list could! > > Allen, as an aside--I would tend to agree with you regarding pitting on a > thin puck, but I don't see a difference in coffee on the screen--I get that > no matter what. I will say for sure, however, that when I have things dialed > in well, my pucks in the knockbox are firm, somewhat pliable, and with the > dent from the screen center stud visible. They don't crumble and they're not > sloppy wet. They will frequently just stay on the knockbox crossbar, slight > bent around the bar, and not fall into the box. It's a beautiful thing. > > Pete, You can find a lot of past posts on dosing also, but there are two > basic philosophies--dosing by weight and dosing by volume. By weight gives > you precise control over how much grind you put into a puck, i.e. you measure > out 14g or 20g or whatever and then grind it into the PF, distribute and > tamp. Dosing by volume is easier, because you just grind into the PF, use > whatever distribution method suits you, then level off the basket before > tamping. Dosing by volume also accounts for the fact that different roast > levels weigh different amounts for a given volume--i.e. a dark roasted bean > is lighter in weight than a light roasted bean. So by volume you will always > have the puck be approximately the same thickness. By weight will give you a > more "known" starting point when you're trying to dial in a specific roast or > blend that you'll be using again and again. Members of this list get amazing > shots both ways; I dosed by weight for a long time then switched to volume a > couple of years ago, and have been very happy with both--I'm just lazy and > like the convenience of volume. When I really want to work on a specific > coffee, though, I use weight to really split hairs. > > Regarding puck thickness, you will also see a dented line in the PF basket > (at least on the double basket), and that is a "dosing line". The puck > should ideally come to about the bottom of that line in order to have a good > dime test and a good pull. Obviously if you dose by weight you will vary > widely from that line, but not to worry--you will be using taste to guide > you, and your main adjustment will be +/- weight, with minor tweaks in grind. > Dosing by volume you will most always hit that line more or less dead on, > and then your adjustment will be the coarseness of the grind instead. > > While I strongly support your efforts to dial in the precision/science > aspects of the machine, I would also suggest that espresso is a dance. You > are dealing with at least five variables at a time, and you usually won't > have perfect control over all of them. I can think of: coffee blend, roast > level, bean age, grind, distribution, tamp, relative humidity, brew pressure, > brew temperature, water hardness, etc. etc. In the beginning, try to use a > single coffee over and over and try to only change one thing at a time until > you understand what that change means. Over time, you will find that it will > become second nature to move with the weather, the roast, the age of the > beans, etc., and you will only waste maybe a shot or two before you hit a > good combination for that day. Just avoid the temptation to start tweaking > everything at once, i.e. "that sucked, maybe I'll drop brew temperature, > grind finer, use more coffee, and tamp harder!" If it ends up being a great > shot, you have no idea what change made the difference. > > One other word of caution is to ignore "absolute" advice. There are some > good guidelines out there, but they are just that--guidelines. For example, > the "golden rule" states that a good espresso pull with yield 2-2.5 ounces of > espresso in 25 seconds or so. While this works out very well sometimes, I > will also say that the very best shots I've ever produced have included some > that yielded 1.5 ounces in 40-50 seconds. Does that make the shots bad? No. > They tasted amazing, and so I did something right. The "rules" will give > you an approximate starting point, but your unique set of variables will be > different than anyone else's. > > A few things that made immediate, dramatic improvements in my shots: > > --Get a tamper made, that fits your PF basket precisely. This will more or > less eliminate side channeling (and don't try to polish with the Thor, it > will wreck your puck). http://www.thortamper.com/ > > --Use the Weiss Distribution Technique. I use a stainless canning funnel > (ebay) instead of the yogurt container. I cannot stress enough how dramatic > of an improvement this was. My "needle" is an easter egg dipper with the > small end cut off, or an unfolded paper clip in a pinch. :) > http://www.home-barista.com/weiss-distribution-technique.html > > --Home roasting (I use 70% decaf and it is cost-prohibitive to get this fresh > enough for decent shots in pre-roasted form--4 days old or less). > > --Lower brew pressure--9 bar or so with a blind PF, 8.5 bar or so during > brewing. I have found higher pressures (12 bar) to be too high and hard to > overcome channeling. > > Everything else has seemed to be variable, based on coffee type, roast level, > etc. > > Anyway, not sure how I got off on this (very long) tangent, but I guess it's > a metaphor for the whole process. :) Enjoy the new machine and hit us with > questions anytime. Hope you're getting some good shots already! I am > eagerly awaiting my PID and rotary pump conversion kits, which will arrive > next week. > > best, > Ben McC > Seattle, WA > > On Mar 3, 2011, at 11:26 AM, Allen Worrall wrote: > >> Ben, does the position of the handle have any influence on the distance >> between the screen and the packed coffee? And if so, does this have any >> significance? I have the impression that if I let the space between the >> screen and the coffee become too large, (by not using enough coffee volume, >> which in turn is affected by the grind) after the pour the surface of the >> coffee puck is eroded and pitted, and there is lots of coffee on the screen. >> >> Allen, in Fairbanks, Alaska (But in May moving to Lakewood, WA, near Tacoma >> and Seattle, so maybe we will meet someday at an espresso conference). >> >> -----Original Message----- From: bmacpiper >> Sent: Thursday, March 03, 2011 7:46 AM >> To: Brewtus >> Subject: Re: Newbie Question #2 >> >> Hey Pete, >> >> If your machine arrived really cold, the gasket is just hard and will >> soften at room temp and/or operating temp. Also, the gasket comes in >> various thicknesses, so you can always get a thinner one if you really >> need to. I use a Rancilio bottomless PF, and the 8.5mm thickness >> gasket works fine for that and the original Brewtus PF. Here is a >> place to get gaskets (good to replace once or twice a year anyway): >> >> http://www.chriscoffee.com/products/home/isomacparts/e61groupgasket >> >> You would order one of the first three in the drop-down list. I >> believe the original on the B2 was 9mm, because when I got the >> Rancilio, I could barely lock it into the group, and had to get a >> thinner one. As an aside, there is no "correct" position for your PF-- >> the basket is round, so it makes absolutely no difference where the >> handle is in that respect. Your primary concern is that the PF gets >> locked in securely, so that it doesn't come loose under pressure and >> shower you with near-boiling water/coffee. I have used machines that >> barely got to the 7 o'clock position, and were totally fine, but >> obviously getting towards 6 o'clock gives you better/full engagement >> of the ears on the PF into the group. Just don't yard on the PF >> handle--it is unnecessary. A good firm twist is plenty--if you're >> moving the machine, you're pulling too hard. >> >> Since we're talking about changing gaskets, I'll mention to you that >> changing your group screen once or twice a year is another easy and >> cheap way of keeping your shots top notch. This is a part that can't >> be cleaned effectively, and over time builds up crud. Search my >> previous post on this, and there are pictures in the gallery of a >> screen that I tore apart after significant cleaning, i.e. more than an >> hour soaking in Cafiza. The pictures speak for themselves. (The post >> is here, fourth one down with my name on it: >> http://groups.google.com/group/brewtus/browse_thread/thread/d1731f9f2ad64ac0/4989e48d94e67cdd?lnk=gst&q=bmacpiper+screen#4989e48d94e67cdd >> ) >> >> Screens here, use the first one in the drop-down list: >> >> http://www.chriscoffee.com/products/home/isomacparts/faemae61groupscreen >> >> best, >> Ben McCafferty >> Seattle, WA >> >> >> >> >> -- >> You received this message because you are subscribed to the Google Groups >> "Brewtus" group. >> To post to this group, send email to [email protected]. >> To unsubscribe from this group, send email to >> [email protected]. >> For more options, visit this group at >> http://groups.google.com/group/brewtus?hl=en. >> -- >> You received this message because you are subscribed to the Google Groups >> "Brewtus" group. >> To post to this group, send email to [email protected]. >> To unsubscribe from this group, send email to >> [email protected]. >> For more options, visit this group at >> http://groups.google.com/group/brewtus?hl=en. >> > > -- > You received this message because you are subscribed to the Google Groups > "Brewtus" group. > To post to this group, send email to [email protected]. > To unsubscribe from this group, send email to > [email protected]. > For more options, visit this group at > http://groups.google.com/group/brewtus?hl=en. > -- > You received this message because you are subscribed to the Google Groups > "Brewtus" group. > To post to this group, send email to [email protected]. > To unsubscribe from this group, send email to > [email protected]. > For more options, visit this group at > http://groups.google.com/group/brewtus?hl=en. > -- You received this message because you are subscribed to the Google Groups "Brewtus" group. 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