chasemonster Senior Member Joined: 3 Jun 2010 Posts: 364 Location: Chicago Expertise: I love coffee
Espresso: Rancilio Audrey Grinder: Hario Mini Mill Drip: V60
Posted Wed Oct 26, 2011, 9:07pm Subject: Re: It has arrived - Breville Dual Boiler BES900XL!
samuellaw178 Said:
I believe the OPV functions to limit the maximum pressure you would get in the system. Assuming the OPV is set to 9 bars, coarse grind will result in fast water flow with a pressure lower than 9 bars (The pump doesn't have a chance to build up enough pressure). A proper grind size (proper flow ~2oz in ~25 sec) should give about 9 bars. A very fine grind (almost none or very little flow) will also give 9 bars because when the system pressure exceeds the adjusted pressure, the OPV will open and relieve the excessive pressure(by letting water flow from the OPV valve).
That is without a doubt the best explanation of the OPV that I have ever read.
In other news, does this Breville machine come with a blind filter basket? If not, can you get one and insert it into the portafilter and perform a backflush type procedure and observe the pressure gauge to confirm what the OPV is set at?
espresso_drinker Senior Member Joined: 26 Oct 2011 Posts: 49 Location: Austin, Texas Expertise: I like coffee
Posted Wed Oct 26, 2011, 9:37pm Subject: Re: It has arrived - Breville Dual Boiler BES900XL!
I have a similar problem. There is no grind setting on my baratza vario at 17 grams of coffee that I can use to get 1.25 -> 1.75 oz of liquid in 25-30 seconds at 9 bar.
The only way I can get close to 9 bar is through a very fast extraction... about 17-25 seconds. I have called the folks at Breville and talked to a guy named Kenji Kawano. It seems he has been tasked with fielding the questions regarding the Breville Dual Boiler machine here in the US. He is incredibly responsive and is very serious about trying to make things right. I was missing a part and he literally fed-ex'ed me another one the next day.
When I asked about the OPV and how it was set from the factory, he had me use the pressurized basket without any coffee and start an extraction without preinfusion. The pressure gauge read 9 bar and he said this was what he expected. I'm now thinking I should probably time how long the pressurized basket will let 2 oz of water through at the current OPV setting....
I'm all for trusting your taste buds. In fact, here is a video of my best tasting shot yet.
Sorry about the shoddy video quality. I had to use the youtube video stabilizing feature since I had consumed enough espresso to wake a dead horse at that point. You can see the parameters in the info.
But... I still want to play with the OPV. I went back to the store (knowing they didn't know what the OPV looked like) and convinced them to let me tinker with their demo before tearing into mine... and yes, I do keep a set of torx/phillips drivers in my car.
I know what some OPV's look like, but I don't know what the BDB's looks like. I snapped a picture of the inside. Anyone know what we're supposed to look for? Group boiler is on the right, steam boiler is in the back.
Will_H Senior Member Joined: 12 Jun 2011 Posts: 38 Location: Seattle Expertise: I live coffee
Espresso: Izzo Alex Grinder: Mazzer Mini Vac Pot: Yama
Posted Wed Oct 26, 2011, 11:46pm Subject: Re: It has arrived - Breville Dual Boiler BES900XL!
While I haven't seen one in person yet, if you can't grind fine enough on a Vario (which I personally know is quite capable of choking up a Marzocco Linea) the basket design is probably at fault. Perhaps the holes are too large, or the sizes are all over the map in size? A OPV that isn't user serviceable (regardless of how hard it is to access) means 10 foot pole for me. Thumbs down.
Posted Thu Oct 27, 2011, 1:24am Subject: Re: It has arrived - Breville Dual Boiler BES900XL!
Will_H Said:
While I haven't seen one in person yet, if you can't grind fine enough on a Vario (which I personally know is quite capable of choking up a Marzocco Linea) the basket design is probably at fault.
Posted Thu Oct 27, 2011, 7:06am Subject: Re: It has arrived - Breville Dual Boiler BES900XL!
espresso_drinker Said:
I have a similar problem. There is no grind setting on my baratza vario at 17 grams of coffee that I can use to get 1.25 -> 1.75 oz of liquid in 25-30 seconds at 9 bar.
The only way I can get close to 9 bar is through a very fast extraction... about 17-25 seconds.
Is your issue that the gauge is showing OVER 9 bar or UNDER 9 bar? If you're saying a fast extraction is the only way to get to 9, that would imply that grinding coarser, thus lowering the pressure, thus meaning your problem is too high a pressure?
When I asked about the OPV and how it was set from the factory, he had me use the pressurized basket without any coffee and start an extraction without preinfusion. The pressure gauge read 9 bar and he said this was what he expected. I'm now thinking I should probably time how long the pressurized basket will let 2 oz of water through at the current OPV setting....
What do you mean by "the pressurized basket"? Is it a backflush disc? Or do you mean the regular perforated baskets? Or does it actually come with a "crema enhancing" pressurized basket like Krups type units? (I haven't seen that on any of the spec sheets so I imagine I'm just misinterpereting.
The amount of time it takes water to come through won't tell you too much. The time is based on coffee providing resistance. All machines will gush water out pretty fast without coffee in the path :)
I know what some OPV's look like, but I don't know what the BDB's looks like. I snapped a picture of the inside. Anyone know what we're supposed to look for? Group boiler is on the right, steam boiler is in the back.
I'm pretty impressed that you actually CAN open the machine up that easily, I'd assumed it was a "sealed box" type of thing given the "factory only" service. That's good to know.
On the other hand, is it just me or are there a lot of plastic tubes in there?
*Edit: I just looked at your video...that gauge is shooting straight to 13 bar....or higher (the gauge does't read anything higher). Yeah, that sounds like the OPV issue struck again (and is worse than I imagined.) A short-term hiccup of OPV issues at launch...ok, I get it, errors happen. All machines have hiccups at launch. But it does make me fear if something that obvious and problematic made it out of the factory in such abundance, without the ability for the dealer to just tell the user "just open the case and adjust this knob", what else may crop up within a year or two that would otherwise be a simple issue, but would require "factory service" to correct?
Posted Thu Oct 27, 2011, 7:09am Subject: Re: It has arrived - Breville Dual Boiler BES900XL!
Will_H Said:
While I haven't seen one in person yet, if you can't grind fine enough on a Vario (which I personally know is quite capable of choking up a Marzocco Linea) the basket design is probably at fault. Perhaps the holes are too large, or the sizes are all over the map in size? A OPV that isn't user serviceable (regardless of how hard it is to access) means 10 foot pole for me. Thumbs down.
I wonder if it's an entirely non-adjustable OPV part actually. Meaning, not that it's mis-adjusted in some units, but that they put the wrong fixed value OPV in at the factory. Like Silvia's used to have before the adjustable V2 came out. (Fond memories....wait...no they're not.)
GlennV Senior Member Joined: 27 Oct 2011 Posts: 28 Location: UK Expertise: I love coffee
Posted Thu Oct 27, 2011, 10:55am Subject: Re: It has arrived - Breville Dual Boiler BES900XL!
espresso_drinker Said:
I know what some OPV's look like, but I don't know what the BDB's looks like. I snapped a picture of the inside. Anyone know what we're supposed to look for? Group boiler is on the right, steam boiler is in the back.
The OPV is the plastic T-shaped piece on the top of the pump towards the upper left of your picture - with its high pressure outlet going to the HX in the steam boiler and the low pressure bypass to the flow meter at the bottom left on its way back to the tank.
I'm intrigued as to how they're doing the preinfusion on these machines btw, as it's not straightforward controlling these vibration pumps at low flow rates and lowish pressures (eg 3bar) . Has anyone tried running one of them against a blind filter or the backflushing disc in an extended pre-infusion mode?
Posted Thu Oct 27, 2011, 12:31pm Subject: Re: It has arrived - Breville Dual Boiler BES900XL!
GlennV Said:
The OPV is the plastic T-shaped piece on the top of the pump towards the upper left of your picture - with its high pressure outlet going to the HX in the steam boiler and the low pressure bypass to the flow meter at the bottom left on its way back to the tank.
I'm intrigued as to how they're doing the preinfusion on these machines btw, as it's not straightforward controlling these vibration pumps at low flow rates and lowish pressures (eg 3bar) . Has anyone tried running one of them against a blind filter or the backflushing disc in an extended pre-infusion mode?
If you're right, then that definitely appears to be a "fixed" OPV, not an adjustable valve by anyone like Silvia V1. Meaning the flaw would have to be that they're either simply broken, or the wrong part was installed. That would explain why the user can't simply adjust it. Plastic tubes, plastic/teflon steam tubes, plastic/teflon brew tubes, plastic OPV....good grief... For $1000+, I'd prefer see a lot less plastic for heavy use....
In terms of preinfusion, that's a good question. I'd assumed it just "pre-wets" using vibe pump early low pressure. But if it has a separate valve for it, or uses steam pressure like the paddle GS3, it would be interesting to know.
lowellw2 Senior Member Joined: 4 Apr 2010 Posts: 30 Location: Austin TX Expertise: I love coffee
Espresso: Breville BES900XL Grinder: Baratza Vario
Posted Thu Oct 27, 2011, 2:22pm Subject: Re: It has arrived - Breville Dual Boiler BES900XL!
Sorry I've been out of the loop and have not responded lately. Sometimes work interferes with important things. I'm still in a testing mode with my Dual Boiler and finally have been able to get fairly consistent shots at 35s (10s preinfusion) and generally get 60ml. Please note the the words "fairly" and "generally". I cannot commit to something more precise. The brew pressure shown getting the above numbers are almost always in the 12-13 range (an occasional 9-10 appears). I noticed that the dosing seems to be a critical factor, but maybe not the only one. If I "under dose" then the crazy slant on the basket does not allow proper tamping pressure. If I over dose a little the puck definitely is right on the screen. I still suspect the OPV may be a central issue (assuming the gauge is accurate).
My current testing centers around doing a blind tasting test utilizing my spouse's palate. Each morning she gets a latte from the Dual Boiler or one from the Vivaldi Mini. So far she consistently prefers the shots from Mini, but I'm using a triple basket on the Mini so I need to use the double and see if she still prefers whats coming out of the Mini. My Mini is a ver. 1 so I have no idea what the brew pressure is doing (possibly a good thing). Oh, the Dual Boiler does come with a so called pressurized basket also (single and double). I think they said it was for use with preground as it somehow is less dependent on grind. I may try those baskets also just to see if something different results.
I note JonR is proposing a road test of the machine in another topic. I also hope/expect Mark Prince will have a followup report soon. The video is exactly representative of my experiences (not as high of pressure). I'd post a video, but do not know how (have an iPhone 4S if someone wants to explain). Right now I'm still wanting this machine to work out and maybe an OPV adjustment is what is needed. However, the taste question is still the critical decider and both my wife and I notice a difference.
espresso_drinker Senior Member Joined: 26 Oct 2011 Posts: 49 Location: Austin, Texas Expertise: I like coffee
Posted Thu Oct 27, 2011, 8:17pm Subject: Re: It has arrived - Breville Dual Boiler BES900XL!
What do you mean by "the pressurized basket"? Is it a backflush disc? Or do you mean the regular perforated baskets? Or does it actually come with a "crema enhancing" pressurized basket like Krups type units? (I haven't seen that on any of the spec sheets so I imagine I'm just misinterpereting.
It is the 'crema enhancing' pressurized basket like my old Krups machine. If you look at the inside of the basket, it looks normal. If you look at the bottom of the basket, there is only one hole.
I'm pretty impressed that you actually CAN open the machine up that easily, I'd assumed it was a "sealed box" type of thing given the "factory only" service. That's good to know.
It was just 4 screws. Two torx and two phillips
On the other hand, is it just me or are there a lot of plastic tubes in there?
It's not just you. But, they probably had to use plastic to hit their price point.
*Edit: I just looked at your video...that gauge is shooting straight to 13 bar....or higher (the gauge does't read anything higher). Yeah, that sounds like the OPV issue struck again (and is worse than I imagined.) A short-term hiccup of OPV issues at launch...ok, I get it, errors happen. All machines have hiccups at launch. But it does make me fear if something that obvious and problematic made it out of the factory in such abundance, without the ability for the dealer to just tell the user "just open the case and adjust this knob", what else may crop up within a year or two that would otherwise be a simple issue, but would require "factory service" to correct?
I read on the coffesnobs forums that it is a quick 5 minute adjustment. However, they are in Australia. It might be possible they have a different spec machine with a different OPV. The person I talked to at BrevilleUSA said if enough people felt the factory adjustment for the OPV was not right, they would gladly figure out a way to make things right. If the BrevilleUSA rep (Kenji) was living in Texas, I think he would have driven to my house to check the machine out. He seemed genuinely interested in making the buyers happy with their machine. In all honesty, I didn't expect this machine to be a Mini Vivaldi or a Duetto so if I can tinker with the OPV and not cause the machine to melt, I'll still keep it, I think.
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.
![espresso_drinker: sbdb1.JPG](javascript:ImagePopup("/images/55015/sbdb1.JPG", 658, 488, "espresso_drinker: sbdb1.JPG");)
= No New Posts since last visit 