Upgraditis: 2-group Grimac Commercial

[JavaB]

Re: Upgraditis: 2-group Grimac Commercial

Robusto...

For a week or two my wife gave me a hard time about my lates :P (shes a big late drinker). The Solis made such beautiful microfoam..... but eventually it clicked and I can now produce equally good microfoam everytime - and in a fraction of the time the Solis took... Commercials are just steaming monsters and VERY unforgiving!!

Espressos were less of a problem - had those sussed in a couple of days.... and can now get pretty much any result I like (mainly combination of brew temp - determined by flush time - and grind)..... I have been getting really great ristrettos!!

122C corresponds to 1.15 Bar boiler pressure- so Id say you are spot on the money. You can increase the boiler pressure to get more steam (as if it is needed :) but that also will require longer cooling flushes. I run mine at 1.1 Bar and find the results are truly excellent - admittedly 7 months after the first shot was pulled - and they were pretty damn good after a couple of weeks use.

[robusto]

Re: Upgraditis: 2-group Grimac Commercial

My wife -- the latte drinker -- tells me her drinks are noticeably improving.

I suppose she goes mainly by taste (silly me!!) while I notice things like the milk got  hot even before I manoeuvrered  the wand into positiion for stretching.

Deficiency in texture, from my perspective, is still a problem as I try to master the Grimacs 4-hole wand and over-abundance of steam.

Im also still coming to terms with the fact that I can now pull two coffees and steam at the same time.  

Often Im standing there, watching and analysing the pour -- as Ive always loved to do --- subconsciously thinking that I then have to wait for the boiler to get up to steam temperature for the milk.  Old habits die hard.

Espressos:  Ive been at work all day, so not much opportunity to do them.  But tonight, doing a Sumatra Mandehling-based bean,  the pour was medium - dark- brown.

Crema extended 100 per cent down to the very bottom of the 60 ml glass until I stopped the pour.   Thats no exaggeration.  Then it rose up and hovered near the top for about 10 mm.

Mouth-feel was a little on the thin side.

Still a lot to learn about when to stop flushing. At the moment Im flushing out about 200 ml of water from each group, looking for tell-tale signs of when enough is enough.  (I know thres a drought on: the water is used for cleaning the portafilters and the rest put in the garden)

The water streams from the  shower screen very bloated (with steam?) at first,   and almost splattery.  It takes 200 ml to go through before the base of the streams appear to thin out and congregate closer to the shower screen and become far less violent.    

Id rather trust a thermometer than looking blindly for evidence that the right temp  for brewing has been reached.  Perhaps its time to find a styrene cup.

--Robusto

[JavaB]

Re: Upgraditis: 2-group Grimac Commercial

Robusto

Sounds like you are making good progress. You will find you will soon master the espressos..... but texturing..... takes a while.

Re flushing. That will vary from machine to machine depending on the size of the heat exchanger, the boiler temperature, the percentage of the heat exchanger in water as opposed to steam etc....

On mine it takes about 120 ml flush if idle for 5 minutes or more and about 60 ml if idle between 2 and 5 minutes.... and about 30 ml if less than 2 minutes (mainly to check if my guesstimated time since the last shot is correct...) if steam comes out with the water..... I then give it one or two 60 ml shots. You can probably guess what my volumetrics are set to from the above.

Yes, you wait until all the hissing and visible steam has stopped and the water flows calmly out from the showerscreen. Often it will start as multiple hissing steams - but will settle down into (generally) one steady stream of water from the centre of the showerscreen.

200ml does seem excessive but I have seen reports of other machines where the users needed to flush that much.....

That of course is the advantage of having the machine plumbed in. It wont save water but will save you frustration.

[robusto]

Re: Upgraditis: 2-group Grimac Commercial

JavaB, thats a smart use of the volumetric buttons -- and once set, you can use any container (or the drip tray) to catch the flushed water without first measuring the desired amount.

Plumbed in is what the machine is designed to be. Ive streamlined its temporary situation so the cables, pipes and containers arent too obtrusive.

The spot where it finally has to go, between the kitchen hotplates and wall, wont leave Mrs Robusto much bench space....Well remove all the panels to lighten it as much as pos and lift it in soon, to see how much space it really takes.

-Robusto

[ozscott]

Re: Upgraditis: 2-group Grimac Commercial

Fantastic pour Robusto. I only get 100% crema when I use home roasted beans - I assume thats what your were?

[robusto]

Re: Upgraditis: 2-group Grimac Commercial

Thats good going Ozscott. A glassful of crema is a much more positive sign that the drink will be good, than staring at black brew.

But mine may have been largely due to the freshness. :-[

Yes, the beans were home-roasted, and just three days old. Theres bound to be an over-abundance of crema with beans which havent yet degassed properly -- they release the gas during the extraction.

That batch (400 grams) is almost depleted, but Ive got another on standby, roasted last Saturday. :P

It weret all that long ago when 400 grams lasted at least a fortnight ...

--Robusto

[JavaB]

Re: Upgraditis: 2-group Grimac Commercial

It weret all that long ago when 400 grams lasted at least a fortnight ...

--Robusto

Geez.... I dont think Ive ever had 400 grams last a fortnight.....

Ive been roasting two 500 gram batches per week for some time now :

[robusto]

Re: Upgraditis: 2-group Grimac Commercial

It weret all that long ago when 400 grams lasted at least a fortnight ...

--Robusto

Geez.... I dont think Ive ever had 400 grams last a fortnight.....

Ive been roasting two 500 gram batches per week for some time now   :

Thats a lot of caffeine, JavaB! :P
At, say, a generous 20 grams a shot, youre talking 50 a week, 7 each and every day.
For two, perhaps?

--Robusto

[Sparky]

Re: Upgraditis: 2-group Grimac Commercial


Maybe JavaB is a perfectionist and there are a lot of sink shots. maybe 2 shots to dial it in and one drinking shot....

I only use about 250 gm per week. But Im the only coffee drinker (apart from the neighbours).

[JavaB]

Re: Upgraditis: 2-group Grimac Commercial

Thats a lot of caffeine, JavaB! :P
At, say, a generous 20 grams a shot, youre talking 50 a week, 7 each and every day.
For two, perhaps?

--Robusto

Yep, neeeeeed caffeine......

Well there are three resident coffee drinkers (me being the worst of course) and lots of "blow-ins"....

So not real hard to go through that much...... but having BeanBay and roast your own probably isnt saving me anything...... consumption has increased far more since using fresh beans - especially in the "blow-in" department.

Guess they must like the coffee. or maybe they just like the price :

[Sparky]

Re: Upgraditis: 2-group Grimac Commercial

I love making coffee for guests and I also like the feedback, honest and brutal. Im my harshest critic anyway. If I get it wrong its quite annoying to hear a guest saying that its "nice".

[robusto]

Re: Upgraditis: 2-group Grimac Commercial

Yes, Sparky, all that perfection going unappreciated.... casting pearls before those undeserving swine....er..... friends.


Perhaps you should be charging commercial rates, JavaB, to recoup some of the outlays.
--Robusto

[ozscott]

Re: Upgraditis: 2-group Grimac Commercial

yep mate - I have noticed that the fresher home roasted - ie in the first 2-3 days produce amazing crema - 100 per centers!

Cheers

[robusto]

Re: Upgraditis: 2-group Grimac Commercial

I hope yours have a matching percentile in the taste department, Ozscott. I cant say mine do.... yet.

But perhaps with more tweaking, more sacrificial beans......

--Robusto

[robusto]

Re: Upgraditis: 2-group Grimac Commercial

Realising Ive got much more steam available than I could possible use on most daily occasions, Ive screwed down the pressurestat to bring down the boiler temperature.

Top of boiler is now about 120 degrees. Cooling flushes are nowhere near as long or splattery. Initial readings of the thermouple in the portafilter showed about 94 degrees, but more readings are necessary.

Im now going to let the machine idle for 30 minutes, and do cooling flushes, measuring quantity against temperature.

--Robusto