After a couple of years of faithful service, my Breville pulled its last shot after the service guy deemed it 'unrepairable'.
I decided to depart the world of 'temperature surfing' and pressurized baskets, roll with the bigboys and acquire some 'prosumer' products. I treated myself and got a Brewtus IV (vibe pump with tank), a Baratza Vario-W grinder and a Espro calibrated tamper. I figured these tools would offer me the ability regulate my brew temps, grind size and weights and my tamp pressure. By using the '2 oz pull at 25 seconds' as a guide, I thought that with some grind adjustments, I'd be pulling superior shots in no time. As it turned out I was wrong! I tweaked with several grind and dose sizes. All I would achieve is pulls that were either too long or too slow (nothing in the 20 to 30 second range). The shots themselves were underwhelming in flavour. Infact my old Breville was putting these to shame. I must admit my methodology was weak, I ll attribute this to my tendency to fall asleep in high school Chemistry classes. One thing that I did observe is that the brew pressure gauge was always around 5 Bar during the extraction. I decided that I needed to start charting my grind weights and setting, aswell as the shot time and the brew pressure. Before doing this I used a blindbasket on the portafilter and adjusted the OPV to 10 Bar (the original factory setting was 12 Bar). The temperature is factory set at 96 degrees Celsius. Using a 14 oz dose, I started with a very fine ground setting and pulled a 35 second shot at 9 Bar. This was promising. My thought was that making the grind more coarse, I would be able to shorten the shot and maintain the brew pressure. I made a couple of very small adjustments with little change in the readings. I then made one more adjustment to the grind and the brew pressure profile changed drastically, after pre infusion, it would build to 5 Bar and stay there until the end where it would go up to 8/9 Bar. It seemed as if it were not possible to 'dial in' a shot with a 14 gr dose. I decided that if I increased the dose size to 16 gr while maintaining the ground coarseness that I would be able to build up the brew pressure to the desired 9 Bar. I would then increase the courseness of the grinds until I achieved an acceptable shot time and brew pressure reading. As it turned out, the increased dose size initiallly did increase the brew pressure to 9 Bar but the shot length was over 60 seconds. I then proceeded to increase the coarseness in small increments. Unfortunately I obtained the same results as I did with the 14 gr dose. Initially getting 9 Bar brew pressure with lengthy shot times. The times start to decrease as the coarseness increase until a point where Bar pressures drop significantly (in this case 6 Bar after pre infusion and only climbing to 9 Bar at the very end of the shot). I achieved similiar brew presurre profiles for 18 and 20 gram doses. (initially 9 Bars but very lengthy shot times...as grind becomes more coarse...unable to achieve full pressure until the end of the shot) I ve run out of beans for the moment (and my patience is next!) I realize the numbers that I ve mentioned are just guidelines and that the flavour of the shot is the ultimate guide. However, I'd like to use this as a benchmark and then tweak from there. At the moment I can't even achieve this. Any suggestions? -- 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.
