Hi everyone, this is my first post. I've been searching for a while and haven't been able to address this issue so I thought it would be worth posting.

The problem: I dial in the beans at my office which has a Rancilio Pro X and Eureka Mignon Perfetto. Over the past couple months, I've had some good coffees but there's almost always a wall of (what I think is) bitterness blocking the true flavours.

I usually buy the same beans for home where I use a cafe roma, and get great results! The depth is lacking but I almost always get balanced shots with no bitterness.

Though I can't easily dial by taste, I have a good sense of the process, choosing a ratio, adjusting grind size etc. Even when I make significant adjustments, the bitterness doesn't usually change much.

I've cleaned the machine and no luck there.

My current bean is Godshot (light Ethiopia) from Saint Henri in Quebec, using their recommended 17.5 in 33 out at around 26 seconds.

Any ideas what else I can try? And what makes the cafe roma so fool proof??

I think of temperature as affecting the "sour", not bitter, but will throw this out. Is there a temperature difference on the office machine? It's my understanding that light roasts require a higher temperatures for optimal extraction.

What grinder is used at work? Could different grinders affect the taste?
I'm sure someone more knowledgeable will chime in shortly.

We're using a Eureka Mignon Perfetto. I've been trying 93C recently, it was at 95C previous.

Thanks! They come with a pressurized basket but I swapped it for non pressurized. I'll get a video tomorrow.

You may want to try comparing the waters used at home and at work. Maybe bring some water home from work to try it in your machine to see if it tastes more similar.

I'll try that, I use bottled spring water at home and water cooler jugs at work - not sure the difference.

Here's a video of a shot. There's 6 seconds of soft infusion before the video starts for a total shot time of 27 seconds.

Well, by just looking at it I think the coffee looks rather thin and the extraction is too fast. I'd guess you could try grinding finer or increasing the dose. BTW, what dose weight are you using? Here is where following the extraction via a bottomless PF would be a great diagnostic aid.