CoffeeGeek - Espresso: Espresso Machines, NS Oscar..Microfoam..Group head temperature..

Espresso: Espresso Machines
NS Oscar..Microfoam..Group head temperature..

Commercial Equipment

Nuova Simonelli, La Marzocco, Rancilio. Nationwide installation. Instant financing options.
www.seattlecoffeegear.com

Not Logged in:

updated topics	new posts	new unanswered
search	faq	sign up

Discussions > Espresso > Machines > NS...

view previous topic | view next topic | view all topics

showing page 2 of 7

first page | last page

previous page | next page

Author

Messages

caeffe
Senior Member

Joined: 30 Aug 2007
Posts: 271
Location: socal
Expertise: I love coffee

Espresso: NS Oscar & Pavoni...
Grinder: Mazzer Major / PeDe Moka
Vac Pot: eSantos / Yama tabletop
Drip: Krups Moka Brew / Bodum Kona
Roaster: I-Roast 1

Posted Mon Nov 26, 2007, 2:09pm
Subject: Re: NS Oscar..Microfoam..Group head temperature..

marksworld Said:

........... I will go ahead and make the trip to a hardware store and get a gauge and some tubing. Can anyone recommend a good post with the best information about building one of these gauges for the steam wand? Thanks!

Mark

Posted November 26, 2007 link

It seems that someone just posted to it so you should see it but if you haven't: Cheap Boiler Gauge

it's essentially a tube that you clamp onto the end of your steam wand with the other end having a tire gauge, put a pipe clamp on both ends to keep them in place. Try to get a gauge that's 0-30 psi since the working pressure you're looking at is ~ 15-20 psi.

marksworld
Senior Member

Joined: 24 Nov 2007
Posts: 15
Location: Pittsburgh
Expertise: I love coffee

Posted Mon Nov 26, 2007, 2:53pm
Subject: Re: NS Oscar..Microfoam..Group head temperature..

faaparasite Said:

I'd be interested to know what your method of measuring temp is and what equipment you're doing it with.

Correctly measuring the water temp can't really be done by simply placing a thermometer in a cup and running water out of the brewhead. There's a lot of reasons for this. First, most thermometers aren't instant read, even if they say they are instant read. The best way is to use a bead probe on an actual digital thermometer like the Fluke, or a true instant read thermometer like the Thermapen. But even if you're using one of those, you can't really get a good read unless you're making the reading inside the PF with a bead probe on top of a fully dosed basket, or with a Scace device. Using a regular thermometer, it might take 3 oz of water or so before the probe warms up enough to read the correct temperature. By that time, your HX machine will not be capable of putting out 200 degree water and 180 or even 160 degree water would not be surprising.

If your wife and mom are used to using large professional machines, it may take a bit of practice to get microfoam with the Oscar. Big dual boiler machines have a LOT of steam pressure, even compared to a fairly large home machine like the Oscar. If they are using a 32 oz pitcher and 8 oz of milk, they are NOT going to get the same results. If you haven't already, try using a 20 oz pitcher and 4-5 oz of milk.

Posted November 26, 2007 link

FAAparasite (you aren't by any chance affiliated with that wretched Federal Aviation Administration are you? :) Thanks for the info! It seems your information is lined up with what "ben" said at NS. The water in the cup is usually 25-35 degrees short of what will be hitting the coffee. I am glad to finally get that cleared up, as I have been racing around everywhere, and nobody seemed to mention that.

SO, long story short. I went and bought a tire pressure gauge and set the whole thing up to the steam wand. I adjusted it to pump approximately 17.5 PSI at the top of its cycle, and it goes down to around 15.4 or so before the boiler turns back on. I figured this is about right according to what NS said and the rest of you all over this board. I am not sure how accurate these tire pressure gauges are, but I tried to read it three to four times to get a consistent reading.

As far as your thought on the more pro-commercial machines, FAAparasite..

faaparasite Said:

If your wife and mom are used to using large professional machines, it may take a bit of practice to get microfoam with the Oscar. Big dual boiler machines have a LOT of steam pressure, even compared to a fairly large home machine like the Oscar.

Posted November 26, 2007 link

If I am reading 1.2 bar at the steam wand, wouldn't this mean that 1.2 bar is 1.2 bar no matter what machine it is on? Even if it is coming out of a larger dual boiler machine. The only thing I can think of is that it could maintain a consistent 1.2 bar through the steaming process. Then again what do I know, I have no educated background that could give me any sort of expertise on this subject.

Can you elaborate? Thanks!

Mark

tsquared
Senior Member

Joined: 12 Aug 2007
Posts: 13
Location: Victoria
Expertise: I love coffee

Espresso: NS Oscar,
Grinder: macap

Posted Mon Nov 26, 2007, 8:59pm Subject: Re: NS Oscar..Microfoam..Group head temperature..

I just got a used Oscar this week from ebay. After a few hours cleaning it (I don't think the previous owner everdid!!) it worked fine--but I am on the learning curve with the 4 hole steam wand. My previous machine was a Solis SL-90 and I could make great foam with that. After 3 sessions with the Oscar, the foam is improving but I might try the toothpick trick that someone suggested. BTW--I am thrilled with the quality of the espresso--great taste and lovely crema. I use a locally roasted bean here in Victoria and have a Baratza Virtuoso grinder. T2

faaparasite
Senior Member

Joined: 19 Jun 2003
Posts: 288
Location: Dallas Metroplex
Expertise: I love coffee

Espresso: Bezzera BZ99
Grinder: Mazzer Super Jolly
Drip: Technivorm

Posted Mon Nov 26, 2007, 9:52pm
Subject: Re: NS Oscar..Microfoam..Group head temperature..

marksworld Said:

FAAparasite (you aren't by any chance affiliated with that wretched Federal Aviation Administration are you? :)

Posted November 26, 2007 link

Yes, as both an employee and a customer.

marksworld Said:

Thanks for the info! It seems your information is lined up with what "ben" said at NS. The water in the cup is usually 25-35 degrees short of what will be hitting the coffee. I am glad to finally get that cleared up, as I have been racing around everywhere, and nobody seemed to mention that.

SO, long story short. I went and bought a tire pressure gauge and set the whole thing up to the steam wand. I adjusted it to pump approximately 17.5 PSI at the top of its cycle, and it goes down to around 15.4 or so before the boiler turns back on. I figured this is about right according to what NS said and the rest of you all over this board. I am not sure how accurate these tire pressure gauges are, but I tried to read it three to four times to get a consistent reading.

Posted November 26, 2007 link

Tire pressure gauges are inherently inaccurate. I have 4 and get 4 different readings when checking my tires. I've never used one for checking an espresso machine, but I can't imagine them doing a very good job.

Personally I have a digital thermometer that accepts K-type probes and I use the method Schomer described years ago:
http://www.espressovivace.com/archives/lucidcafe/LC13.pdf

You can pick up a Fluke 51 on flea-bay for around $50 or so. I have an off brand chinese model, but it works great and even accepts dual inputs. I'm actually very glad I got it because I use it for all sorts of things around the house. You can also get a variety of K-type probes for a variety of uses. I bought an instant read bayonet probe which is great for cooking.

marksworld Said:

As far as your thought on the more pro-commercial machines, FAAparasite..

If I am reading 1.2 bar at the steam wand, wouldn't this mean that 1.2 bar is 1.2 bar no matter what machine it is on? Even if it is coming out of a larger dual boiler machine. The only thing I can think of is that it could maintain a consistent 1.2 bar through the steaming process. Then again what do I know, I have no educated background that could give me any sort of expertise on this subject.

Can you elaborate? Thanks!

Mark

Posted November 26, 2007 link

Ah, but they don't steam at 1.2 bar! Large commercial machines often have steam boilers that are twice the size of your Oscar's and are typically set between 1.5 and 2 bar max. It may not seem like much, but that's a world of difference.

In a single boiler machine, even if it's a HX machine like yours, there's always the compromise between steaming and extracting. Personally I always set my boiler at what produces the best espresso. The exception to this rule would be if you had some sort of PID setup that allowed you to easy switch between brewing and steaming settings.

Your machine has excellent potential to produce great microfroth even at modest boiler settings. You just have to think in terms of smaller pitchers and smaller quantities of milk compared to a true commercial machine, and it just takes lots of practice.

ethom
Senior Member

Joined: 24 Nov 2012
Posts: 63
Location: Pittsburgh
Expertise: I like coffee

Espresso: NS Oscar, Silvia broken :o(
Grinder: Vario
Drip: Bosch

Posted Tue Jan 8, 2013, 4:36pm
Subject: Re: NS Oscar..Microfoam..Group head temperature..

caeffe Said:

A couple of other things - I find that most Oscars come with too much pressure at the brew head. You'll need a brew pressure gauge with is basically a gauge attached to your portafilter. My oscar was pegged at 200 psig+, it should be around 130-150 (depending if you measure the pressure with some flow)

But again, if your espresso is fine - you may not need to adjust anything.

Posted November 25, 2007 link

I recently bought an Oscar via Craigslist and, though I haven't tried measuring, have a feeling that the brew pressure is very high. It's tough to choke with a Vario on finest grind. How does one adjust the brew pressure on Oscar?

Tom...

sn_85
Senior Member

Joined: 1 Dec 2011
Posts: 131
Location: Fort Lauderdale, FL
Expertise: I love coffee

Espresso: Quick Mill Andreja Premium
Grinder: Baratza Vario

Posted Tue Jan 8, 2013, 7:33pm
Subject: Re: NS Oscar..Microfoam..Group head temperature..

ethom Said:

Posted January 8, 2013 link

you do realize the last post in this thread was in 2007 right?

ethom
Senior Member

Joined: 24 Nov 2012
Posts: 63
Location: Pittsburgh
Expertise: I like coffee

Espresso: NS Oscar, Silvia broken :o(
Grinder: Vario
Drip: Bosch

Posted Tue Jan 8, 2013, 7:41pm
Subject: Re: NS Oscar..Microfoam..Group head temperature..

sn_85 Said:

you do realize the last post in this thread was in 2007 right?

Posted January 8, 2013 link

Oops. Sorry to break protocol. I have been reading most anything I can find on the Oscar to figure out how it works and and didn't really think about the last post date. The machine was made somewhere around 2007. Is the thread obsolete? Is there a newer section I should be looking at? What am I missing?

Coffeenoobie
Senior Member

Joined: 11 Dec 2011
Posts: 2,317
Location: PNW
Expertise: I like coffee

Espresso: N S Oscar
Grinder: Vario W

Posted Wed Jan 9, 2013, 11:08am Subject: Re: NS Oscar..Microfoam..Group head temperature..

I have no trouble choking my Oscar with Vario. have you adjusted your vario? fresh beans? tamping, are you taping the portafilter? The OPV might not be working, did you clean Oscar when you bought it?

Coffeenoobie Buying advice: GRINDER GRINDER GRINDER. Don't cheap out on the grinder. My coffee treasure map... Click Here (maps.google.com)

Markarian
Senior Member

Joined: 27 Jun 2012
Posts: 474
Location: Seattle Area
Expertise: I love coffee

Espresso: Modded Nuova Simonelli Oscar
Grinder: Vario-W, Mazzer Super Jolly
Drip: Moka, Aeropress, Melitta 102
Roaster: Wear-Ever Popcorn Pumper

Posted Wed Jan 9, 2013, 1:18pm Subject: Re: NS Oscar..Microfoam..Group head temperature..

Wow, this sounds familiar! I recently had a faulty neplax valve on the group that I had to replace. A good way to see if it is faulty is to take the cover off and see if water is flowing through the tube on the left of the group when you pull a shot or backflush. If it does, chances are you could benefit from NS' upgraded neplax valve as I did (my machine was made in 2004-2005, I think). But yes, you should be able to grind nearly to Turkish before the Vario chokes (I recently DID try to use the Vario for Turkish. Do NOT do this).

ethom
Senior Member

Joined: 24 Nov 2012
Posts: 63
Location: Pittsburgh
Expertise: I like coffee

Espresso: NS Oscar, Silvia broken :o(
Grinder: Vario
Drip: Bosch

Posted Thu Jan 10, 2013, 12:01pm
Subject: Re: NS Oscar..Microfoam..Group head temperature..

Coffeenoobie Said:

have you adjusted your vario?
fresh beans?
tamping, are you taping the portafilter?
The OPV might not be working, did you clean Oscar when you bought it?

Posted January 9, 2013 link

- I have not adjusted the Vario with the calibration tool. It starts to sound laboring with the right adjuster all the way up on fine and the left one about halfway up. When checking, I noticed that ground coffee is accumulating in both the adjustment slots (Photo below). This doesn't look right to me. Is it unusual?
- Beans are fresh from a local roaster. Whatever I can't use in a few days, I freeze in mason jars. I have some older Costco beans that I use for decaf and easily recognize the big difference.
- Tamping, yes at ~30 pounds (practiced with a bathroom scale) with a RW aluminum.
- Cleaning: I removed the brew head screen and dispersion plate and soaked them in Cafiza. They were really black with gunk and it took some scrubbing to get them clean. Then back flushed one time a few weeks ago with Cafiza but didn't see much brown come out, mostly just soapy white.

If it matters, I occasially see some water, maybe a half once, under the drip tray when I remove it.

(Click for larger image)

showing page 2 of 7

first page | last page

previous page | next page

view previous topic | view next topic | view all topics

Discussions > Espresso > Machines > NS...

updated topics

new posts

new unanswered

faq

Not Logged in: log in
Discussions Quick Jump:
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.

Caffeine

A mobile app for coffee enthusiasts. Available for iOS and Android
bit.ly/caffeine-ap