Espresso acidic with my ROK...

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Stephane_Paris
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#1: Post by Stephane_Paris »

Hi, too many of my espresso are acidic with my ROK.. , i try to grind more fine and water at 98° (pre heat the ROK) but too acidic.. any advice ?

Thanks
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thepilgrimsdream
Posts: 310
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#2: Post by thepilgrimsdream »

It could be your coffee, water or channeling. More details?

randyh
Posts: 267
Joined: 8 years ago

#3: Post by randyh »

I would suggest starting by getting a bottomless portafilter for the ROK. Can be found here:

https://espressounplugged.com/naked-portafilter

This is the only way to objectively evaluate your distribution and tamping skills. Work on getting a picture perfect pour from the bottomless portafilter first, ie no channeling, spritzing, dead spots etc.

It is definitely possible that even with perfect pours, espresso from the ROK will still taste sour/underextracted, and this is because it will always brew on the cooler side. There is no effective way to preheat the ROK enough to brew at >200F.

If that's the case, grinding finer and reducing the dose will help, or use a darker roast.

Lastly, are you filling the chamber almost full with boiling water? If not, I would recommend doing this, as it will increase the brew temperature as well as increase the pressure you are able to generate which will help increase extraction etc. Use only boiling water, and fill to 1cm from the top.

Hopefully you will be able to get good espresso from your ROK. I have had some success, but in the end felt limited with what the ROK could do, so I sold it and waiting for my Espresso Forge to ship. By most accounts here on HB, the Forge is capable of making high quality espresso consistently.

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Stephane_Paris (original poster)
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#4: Post by Stephane_Paris (original poster) »

More details : I use 98 ° water because i get better result then 95° result with a beans coffee (who is not made anymore becausee it's a saison coffee)

10 sec infuse arm up before push down

For now i can't reduce the dose because i have only a 51mm tamper so i can't go under the line of the basket with it, i ordered a 49,7 tamper here https://www.etsy.com/fr/listing/2594102 ... e_active_4 and he's on the way to me.

i fill water at 1cm from the top since the begining.

I'll buy a darker roast this afternoon ;)

I ordered a naked portafilter who is on the way to come

I tested to preheat like you said more the portafilter (put it under hot water then put some 98° on it) clean it, and put the cofffee, result is the coffee go over More fast and have a ugly white crema (without warming so much the portafilter i get good crema 2 mm and darker) that make me stop warming so mush the portafilter..

Thanks for you help, hope i'll get good result finally ;)
LMWDP #588.

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Stephane_Paris (original poster)
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#5: Post by Stephane_Paris (original poster) »

As with my 51mm tamper i can't go under the line of the portafilter and feel i didn't have enough pressure on the coffee i made a test, after use the tamper, put again some coffee and tamp again, that work ! not for all coffee beans, but for 2 or the 3 i use that work ! 8)
LMWDP #588.

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Stephane_Paris (original poster)
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#6: Post by Stephane_Paris (original poster) »

Problem solved, i press more, goind under the line inside the portafilter (using a smaller tamper)
LMWDP #588.