Richard, My experience matches Dennis's observation: 1. 7 usually works well for most people and 2. rapid successive shots slowly rise in temperature. And perhaps some ancient history might help you get comfortable with how you could get to where you want to be without spending a lot of money on anything but beans.
Just playing with the offset based on E-mail comments can be a little frustrating ... you need to insert some tongue testing into the process. You should also be aware that the machines vary slightly from unit to unit and will be affected by things you do, such as add insulation or jack up the steaming pressure/temperature. But the factory setting is a good place to start. And keep in mind that the whole offset thing is not an "error; it's just an adjustment that is not currently helping you achieve the result you want. Initially, the controller display issue was strongly influenced by manufacturing considerations. The "offset" was especially useful because it helped keep the displayed read-out to two digits (e.g.below 100C) ... which made the part cheaper to buy, even though the boiler may sometimes be over 100 C and measuring things in F would be a lot nicer for folks in the US. An offset's task was to "translate" the boiler water temperature, which was needed in a feedback loop for heater management, into a best estimate of the puck temperature ... which is what affects the taste. To my knowledge, no one has developed an actual puck sensor arrangement that is durable enough to survive routine kitchen use, ... although some people have placed a sensor in the group's water path in order to get closer to the puck. If you have not changed the "off-set" from the way it was set when your B-x arrived from WLL, then the reading on the controller display and what you could measure at the puck should be "about" the same (as Dennis reports) and the pattern will at least be very stable/consistent from day to day. If your shots taste bitter, you should try dropping your "displayed" temperature several degrees, since that is the first suspect in bitter shots. You should decide if the shots then taste less bitter ... and perhaps more sour. Note: You are going to need a lot of testing shots because the temperature will vary a little depending on how much time and water has flowed since the last heat cycle (red dot on.) When Abe and I PIDed our supposedly identical machines, we found that they needed different offsets ... more cooling occurred on my machine on the way from the center of the boiler (where the probe sat) to the face of the puck (where we had a PF with a probe) than occurred on his. As I recall, the difference was about 5+ degrees F. We also used a 5 digit display and no offset in order to deal with actual temperatures that were accurate to within a tenth of a degree F. (It does still feel a little weird to say to my spouse, "Gee, I think I need to jack this blend up to 212F for decent shot.") At one point, WLL experimented with changing the offset for all the machines on hand or in transit to a different number. (Since the B originally was only for the US market, WLL could specify a particular value for future production.) So some units went out with an offset of 5 for a period and then they went out with 7. But I don't recall where all that stands at the moment. RE: the Scace: My understanding from parties involved is that the Scace was originally developed in the context of measuring temperatures in big commercial (LM) machines with massive boilers, IIRC. There is a highly specified protocol for taking the "official" measurement. It involves lots of shots and water flow. The original intent behind developing the unit was to assure that the machines used in competition were producing exactly the same water temperature at the puck. (No competitor should be disadvantaged by having an "off" machine in the practice area or at a competition station. Competitors have actually insisted on having the temperatures checked because the felt they had been penalized by their unit.) The Scace has always seemed a little "slow" to me (I have one) and Sean built a similar puck based unit with a slightly faster probe that we used for our puck measurements. Bottom line here is that since the Scace (and a Fluke) is an expensive addition to your coffee toys, there is a way around it. You should ignore what the actual number on the controller reads and discover what number needs to be there to make the coffee taste just the way you like it ... consistently ... over several shots ... at varying intervals ... with whatever flush you deem appropriate. When you find that displayed number, then you can begin to play with the offset to create a displayed number that looks like the recommendation. If you like Belle at 96 on your readout and Klatch says it is best at 201F (93.888 ... C), then change your offset to make the readout say 94 and see if that makes other coffees taste pretty good at the roaster's recommended setting. If so, then be like Dennis and quit worrying about that issue. Regards KittJ ----- Original Message ----- From: "Dennis Keating" <[email protected]> > 7 is the best setting IMO. I have never strayed from that. I have a > thermofilter, and the water temp at the puck is spot on whatever is preset > on your controller. If you flush or use lots water rapidly it should start > to creep up.(like a pair of cheap undeerwear) - Dennis > ----- Original Message ----- > From: "Richard W" <[email protected]> > > One reason I wanted to an accurate temperature readout is that many of > the top coffee roasters, like Paradise and Intelligentsia, are now > starting to recommend different brew tempertures for different > espresso blends that they offer. --~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---
