nuketopia wrote:If you look on your front panel gauge, you should be able to read the steam boiler temperature. Hopefully, it is around 1.2-1.4 BAR. But I have read that the PID version is set to only 1.1. That's pretty cool.
With a properly tuned HX loop, 1.1 bar should be ample, especially when it doesn't cycle like a pressurestat boiler would. My Sirai cycles between 0.8 and 1.1 and I enjoy light roasted coffees that require higher temperatures with no issue. Being that he was able to tame the flavor by flushing more and not allowing a recovery, I think it's safe to say that his group gets hot enough...
nuketopia wrote:Also, the brew pressure gauge should show some pressure while it is idling. After purging the water, look at the brew pressure. It should remain with some residual pressure and hold it for an extended amount of time.
If it doesn't hold pressure, or the nut at the top doesn't stay hot - water is not circulating and you'll get cold brew temperatures.
Mara has a 3 way valve for the brew pressure gauge that drops the gauge pressure to zero after a shot. So while this is good advice, it doesn't apply to the machine...
correarc1 wrote:I think now I'm at a point where the awful sour/bitter taste is mostly gone. Now, I still feel like I need to bring out the sweetness of the beans as it still doesn't taste balanced.
You're over a major hurdle. 5 seconds is not a magic number; it's just a repeatable blind shot in the dark. I would say that you're close though. Next up, flush for 10 seconds after the calm. Note what you taste. Write it down. Really taste
it. Then just reach the calm and dont flush any more at all. TASTE. Which was better? WHY was it better? This process isn't about making your espresso balanced and great. It's about understanding what too hot, too cool and just right taste like.
Unfortunately, you still have to work out grind, dose and yield after you find the right temp. It's a VERY iterative process. Get the temp close. Then work on grind. Then double check temp. Then work on dose. Then adjust grind again to match dose. Then once you've settled on them, check the temp again. Go one second cooler, one second hotter, notice the difference in flavor.
Then there's yield. Shorter shots (ristretto) might like to be hotter to improve extraction. Lower doses with finer grinds tend to be sweeter. You can increase the dose with a finer grind and pull a ristretto in a typical brew time, or stretch it longer and get a really long normale shot. The options are endless. And all this is just in figuring out the brew parameters for one coffee. When you start experimenting with more roasts, you see why we call it the rabbit hole. It just never ends.
But fret not!
There are oodles of tasty shots in the process. Once you get the temperature nailed, you're chasing great shots and navigating a sea of coffee that is really quite good even if you just stick to the 18g in, 36g out in 23 to 35 seconds ritual and just adjust grind to see if you like 23 seconds better than 35. But i will tell you that the 1:2 ratio is not king. Its just a starting point. All coffees are different, so once you get consistent do not be afraid to experiment.
Stick with it!