As a relative new-comer to this, I can use some tips on knowing how to gauge temperature flaws and what to do about them. I'll start with what I (think I) know: too cold of an extraction tends to taste sour, too hot is bitter.

I use a cimbali jr.- a fairly stable hx. I've adjusted the pstat to approximately 1.1 bar and follow a fairly simple flush routine which yields a consistent result. I'm not so concerned about a thermometer read out, as I would prefer getting a better handle on tasting a flaw and how to correct it (or at least how to approach correcting it).

Here's what prompts my questions. I started with a triple basket on my machine since it lacked a stock basket. When I switched to a double basket, I noticed immediate improvements in channeling, but fairly bitter extractions with most blends and decaf's but pretty good balance from most SOs, in particular a brazil ipanema with a light roast seem spot on. A very long flush regime helped but did not cure the bitterness/balance issues with blends and darker roasts. Since the triple basket did not have as much of an issue with bitterness, I figured the larger dose or basket must in some way compensate for a higher temperature of water, so I updosed in the double, which helped some with bitterness, though this presents other issues with my machine which doesn't behave well with updosing (probably since the screen protrudes into the basket fairly far without clearance below the dispersion block).

a) am I looking at this correctly as a temperature issue?
b) is there another way to account for cooler water besides a longer flush which I've been doing (or adjusting the pstat when I change coffees) and/or updosing, changing baskets?
c) is it better to adjust the pstat lower and change the flush regimes to attempt to cover both the darker roast/blends and lighter roast SOs?

It sounds like you are doing the right corrections. Most beginners pussy foot when making changes, and this may be the problem you are having. It's a lot more illuminating to make big changes and overshoot, since the effect on the shot is dramatic, and you will know if you went in the right direction or the wrong one. If you inch along with your changes; you'll get almost no feedback in the cup, and won't know if you are inching towards or away from your goal.

About boiler pressure. The Junior has plenty of steaming power, so you can set the pressure lower if you need. If you do mostly one shot at a time after the machine has been idling, your ideal boiler pressure is one that gets just the slightest boil when you start flushing. This will minimize the flush amount and maximize the usable brew temperature range. Again, play it large, and find the limits: flush just one second past boil, and then, say, 8 seconds past boil, and see what happens.

Thanks, I'll give the bigger moves a try.

If I was running a Junior on a pressurestat (as opposed to a PID), and if I was not making large milk drinks or many milk drinks back to back, I'd set the pstat lower, like around 0.9 bar at the top of the pstat cycle.

ken

Ken Fox wrote:I'd set the pstat lower, like around 0.9 bar at the top of the pstat cycle.

ken

Thanks Ken. I played with the pstat yesterday and ended up at about .95 for the high end, though I know that my gauge isn't accurate enough to claim specificity. Little bitterness with the Peru decaf I have at the moment. The Brazil Ipanema didn't seem to suffer from the reduced temp, but I suspect it's more due to that bean's tolerance than anything I'm doing.

I only do a couple of ounces of milk in the morning for myself and my wife; however, the junior is getting ready to go into our law office where I know at least a couple of coworkers love the bigger milk drinks. I still doubt I'll push the limits of steaming on the junior.

I'm going to keep going as Jim suggest and really crank it down to get a better feel for the bookends of a setting. We'll see how that goes.