Today I descaled my Bezzera BZ10 for the first time and now the brewing pressure is slow to rise and does not go nearly as high as it did before. I did a very thorough rinsing after the descaling and tried backflushing after I noticed the problem. This did not help. Have i gummed up a sensor or messed up my pump? Not sure what to try next.

Hi there,
I would guess that, similar to the cardiovascular system, tubes with a reduced diameter will create a higher pressure - now that you have descaled everything, the pressure will be less as there is less force needed to push the water through the larger openings.
I would probably say that adjusting your pump bypass to slow the water flow and increase the pressure will bring you back where you want to be.

Thanks for you thoughts but it seems that when the machine was new the pressure gauge was reading in the 10-11 psi during brewing. Now it is reading 5-6 even though the shot seems to be fairly normal in volume and appearance. It is possible the gauge was fouled during the descaling process. I might descale again in a couple of days and see if that clears things up.