MTmama Senior Member Joined: 15 Feb 2012 Posts: 49 Location: Bozeman, MT Expertise: I love coffee
Espresso: Alex Duetto Grinder: Super Jolly
Posted Sat Mar 3, 2012, 6:13pm Subject: Alex Duetto's Pressures too HIGH!
I finally had a day to really play with my new Duetto today (ended up sick all week). I was pulling Redbird which was my favorite on my Silvia. It didn't matter was I did the shots were bitter, bitter to the point of I couldn't even swallow them. For some reason it dawned on me to check the pressure gauges and they were both really high. The BREW pressure was resting at 4ish and climbed to 11 when pulling a shot. The STEAM pressure was resting a 1.75 and would occasionally creep into red!
Alarmed I started doing some research and discovered that perhaps the problem was that we did NOT install a pressure regulator on the line to the machine when we plumbed it in. So fine....I ordered one and will install it and in the meantime turned off the machine for an hour, stitched to pour over, and then turned it back on to see it the problem was resolved.
It WASN'T. My BREW pressure is at 0 at rest, but still climbs to 10 when pulling a shot. My STEAM pressure is still resting at 1.75.
I need some advice...besides installing the pressure regulator do I need to adjust the pressure on the actual machine? How do I do this??
Posted Sat Mar 3, 2012, 6:33pm Subject: Re: Alex Duetto's Pressures too HIGH!
Sorry to hear of your woes, but the good news is that this should be easily resolved.
Steam pressure is a setting, and may be is OK where it's at. This will not affect your shots on a Db because steam is a separate boiler from the brew boiler. If you do want to reduce the steam pressure then it just means re-setting the PID at a lower temperature for the steam boiler.
The brew pressure is a differnt issue. It's OK for the resting pressure to be 4 bar when plumbed in (this is residual pressure in the line between the pump and boiler, at the location where the pressure gauge is piped).
We will be most interested in the dead head pressure, that's the reading with pump ON and no flow - like with the backflush blind filter installed. Most folks want the dead head to read between 9 and 10 bar because the brewing pressure when the shot flows will be a little less than the dead head pressure (I have mine set at 9.5 bar).
Your Alex Duetto (IIRC) has a rotary pump, so the rpessure is very easy to adjust. I would go ahead and do the setting with the machine set up on the line pressure since that is how you'll be running mostly. Take the case off and then plug the machine in so you can run it while it is open (leave it off, so you can have it cold for the work).
Locate the pump output and notice that there is a thumbwheel (or a heavy screw) at the end secured by a nut. The thumbwheel/heavy screw is the adjustment mechanism and the nut is the lock. You will want to loosen the nut so thatthe screw can be turned.
Then turn on the machine and put the blind basket in the group. Engage the pump and then adjust the screw while watching the gauge. When it reads 9.5 bar (or whatever is desired) then turn off the pump and tighten the nut (hold the screw steady while tightening).
Double-check to make sure the setting didn't drift before you put the lid case on.
I hope this helps, Jon
EDIT - looks like Rob beat me to it. And he was much better than me, pointing to the manual
jwoodyu Senior Member Joined: 31 Dec 2010 Posts: 704 Location: Michigan Expertise: I love coffee
Espresso: Allex Duetto II Grinder: Mazzer Major Roaster: Poppery
Posted Sat Mar 3, 2012, 8:28pm Subject: Re: Alex Duetto's Pressures too HIGH!
I was wondering what happened and how it was going. Just for reference my brew pressure is also set to 9.5 and I brew red bird pretty regularly with great results. What temp are you brewing at? If it still bitter after you turn it down the pressure you might consider cooler brew temp or coarsen up the grind a bit.
You know those people that want to tell you how to raise your kids but have none of their own? That is how i feel when someone with a kitchen appliance tells me how the merits or dis-merits of my machine or how to use it.
MTmama Senior Member Joined: 15 Feb 2012 Posts: 49 Location: Bozeman, MT Expertise: I love coffee
Espresso: Alex Duetto Grinder: Super Jolly
Posted Sun Mar 4, 2012, 7:56am Subject: Re: Alex Duetto's Pressures too HIGH!
jwoodyu Said:
I was wondering what happened and how it was going. Just for reference my brew pressure is also set to 9.5 and I brew red bird pretty regularly with great results. What temp are you brewing at? If it still bitter after you turn it down the pressure you might consider cooler brew temp or coarsen up the grind a bit.
The adjustment was super easy! It took a few tries because I wasn't sure just how much to adjust so started small and did it in increments. This morning it is brewing at 9.5bars. Results are definitely better. Yesterday shots were fast, and had large bubbles on the crema. Those two problems are gone. I'm brewing at 198 and think I may take your advice and lower the temp. What are you brewing your Redbird at?
germantownrob Senior Member Joined: 2 Dec 2007 Posts: 2,017 Location: Philadelphia Expertise: I love coffee
Espresso: Duetto 3, A Dead Oscar Grinder: Vario-W, Preciso w/Esatto,... Drip: Brazen Roaster: Diedrich IR-1, HT B
Posted Sun Mar 4, 2012, 8:21am Subject: Re: Alex Duetto's Pressures too HIGH!
Redbird is probably a great test for seeing if your brew temp is spot on. When following their suggestion of brewing at 198-200f with an 18g dose and 25-30sec timed from the first drip gives me snickers bar. Since it is faster to cool a machine then it is to get the the machine to stabilized at a higher temp I suggest starting at 201f and adjusting 1f lower to try and nail the snickers bar taste.
jwoodyu Senior Member Joined: 31 Dec 2010 Posts: 704 Location: Michigan Expertise: I love coffee
Espresso: Allex Duetto II Grinder: Mazzer Major Roaster: Poppery
Posted Sun Mar 4, 2012, 12:06pm Subject: Re: Alex Duetto's Pressures too HIGH!
MTmama Said:
The adjustment was super easy! It took a few tries because I wasn't sure just how much to adjust so started small and did it in increments. This morning it is brewing at 9.5bars. Results are definitely better. Yesterday shots were fast, and had large bubbles on the crema. Those two problems are gone. I'm brewing at 198 and think I may take your advice and lower the temp. What are you brewing your Redbird at?
Pretty much what Rob said :) 199 on my PID, 19 gram dose in a 18 gram VST basket. It seem's to me that Redbird is more forgiving on the cool side then on the high meaning I find it gets bitter from too high a temp faster than it gets sour from two a low a temp at least on my setup. Both my major and Vario are pretty comparable to your super jolly so like Rob said as long as our off sets are correct you should be right there in the ball park.
You know those people that want to tell you how to raise your kids but have none of their own? That is how i feel when someone with a kitchen appliance tells me how the merits or dis-merits of my machine or how to use it.
IenBell Senior Member Joined: 17 Feb 2012 Posts: 25 Location: Uk Expertise: I like coffee
Posted Tue Mar 6, 2012, 10:02pm Subject: Re: Alex Duetto's Pressures too HIGH!
Redbird is probably an excellent analyze for seeing if your produce temporary is identify on. When following their recommendation of preparing at 198-200f with an 18g serving and 25-30sec timed from the first drop gives me peanut bar.
Symbols: = New Posts since your last visit = No New Posts since last visit = Newest post
Forum Rules: No profanity, illegal acts or personal attacks will be tolerated in these discussion boards. No commercial posting of any nature will be tolerated; only private sales by private individuals, in the "Buy and Sell" forum. No cross posting allowed - do not post your topic to more than one forum, nor repost a topic to the same forum. Who Can Read The Forum? Anyone can read posts in these discussion boards. Who Can Post New Topics? Any registered CoffeeGeek member can post new topics. Who Can Post Replies? Any registered CoffeeGeek member can post replies. Can Photos be posted? Anyone can post photos in their new topics or replies. Who can change or delete posts? Any CoffeeGeek member can edit their own posts. Only moderators can delete posts. Probationary Period: If you are a new signup for CoffeeGeek, you cannot promote, endorse, criticise or otherwise post an unsolicited endorsement for any company, product or service in your first five postings.
= No New Posts since last visit 