I'm trying to dial in a nanopresso, I'm using a Vario-W with ceramic burrs, the coffee is a medium roast from Indonesia. I grind fine and the shot is sour. I grind finer and the shot is sour, I grind finer and the shot is still sour... tones of texture but quite sour so I grind finer and the pressure is so strong that it begins to suck the seals out and a bunch of grinds dump out. So I try other things to increase extraction... I preheat as much as I can, straight off the boil... and still sour. Longer shot just gives me weaker but still sour. I usually make latte's with it and when you dump a bunch of frothy milk in it then it seems to correct a lot of problems so I don't worry much about it. But all I can get is sour shots with it.

So I tried a page out of this new sciencey thing that coarser can have higher extraction. I went coarser and for the first time ever on this unit I had an astringent shot, it took like 15 seconds and there was a sort of wispy crema. Counter-intuitively I now must go finer to get less extraction...? but I put it away and I'll play with it later.

Does anyone have the nanopresso? what has their experience been with it?

I haven't heard of a nanopresso, but have you tried different beans?

It's called the Wacaco Nanopresso. It's a hand held travel friendly manual espresso pump. It looks a little like a mini thermos. I will be using different coffee very soon and we will see the difference.

I just watched the James Hoffman review and he's not so excited about it, suggesting it's better for pods.

I have the nanopresso and I use it quite often when I go abroad or out of town. The first thing I did when I got it was to remove the little spring from the portafilter so I could use it in non-pressurized mode. Take a look at this: Have you tried it?

Dialing it in was not that difficult on my hario mini - it's about 10-11 clicks from start and it shouldn't be that fine otherwise when pressure builds up, coffee starts coming out from the sides of the nanopresso at the points where is screws in to the portafilter.

The result is never as a proper espresso in terms of thickness and taste complexity but it's more than acceptable.
I hope this helps!

yiorgos wrote:I have the nanopresso and I use it quite often when I go abroad or out of town. The first thing I did when I got it was to remove the little spring from the portafilter so I could use it in non-pressurized mode. Take a look at this: video

Have you tried it?

Dialing it in was not that difficult on my hario mini - it's about 10-11 clicks from start and it shouldn't be that fine otherwise when pressure builds up, coffee starts coming out from the sides of the nanopresso at the points where is screws in to the portafilter.

The result is never as a proper espresso in terms of thickness and taste complexity but it's more than acceptable.
I hope this helps!

It does help, thanks. I knew about the pressurized thing but didn't know it was a recommended mod, I thought it was more of a zealous hack. I'll take it out and try my shots again. Would you say your grinds go past espresso and into more of a medium fine territory? I figure the pressure is getting lost when I go finer and this is why finer is not getting me more saturation, not to mention there might be heat loss that contributes. Not that I don't feel the pressure but I'm thinking it escapes through other areas rather than fixed on the coffee.

Right now on my vario I would typically do an espresso on the macro adjustments in the 2 rang, the nanopresso is in the 4 range (I can micro adjust further between the macros). What is your dose? I have the barista bundle and I'm using 15 grams for a dose. I try to do a 1:2 under 30secs but with the grind the flow is pretty fast I just need to pump slower I guess. Right now I'm ganging the flow to know when the pressure/grind is at the right spot. I'm starting to think non-traditional espresso may have non-traditional rules, like the water tank on the barista bundle is huge so maybe it's set up for ratio closer to 1:3

I took the little rubber thing out and figured it would need a finer grind so brought it finer. Pulled the shot (or pressed the knob several times) and it was super fast with little resistance. So I made another shot dropping the grind quite a bit, flow was still fast and pressure low. Both were sour but I'm actually more hopeful with it depressurized as I'm using the resistance of the coffee not some rubber thing. I'll keep going finer to see what sort impact it has. I only do a light tamp too, with this rubber thing out it seems to change all the rules so I might get away with a more firmer tamp.

UPDATE: I think I have the flow right, but still sour shots, lot's of crema but sour. The finer I go the more sour it gets. counter intuitively I have to go coarser to get away from the sour. I think this is a heat management issue and perhaps the water temp drops too much so is always under extracted no matter how fine I go. I'm thinking the design is to be used pressurized with pre-ground espresso from the grocery store, that or pods (with the pod adapter of course) Where I live I can't buy these things locally and would have to order online. But I'm tempted to get the NS adapter kit and try the pods just to see if something not sour can come out. In the mean time I'm going to try and super heat up this unit and get the hottest water I can get in it to see if it can get more extraction.

I finally got a decent shot and the problem was the roast. I just got a darker roast (fully city) and was able to get success from this de-pressurized. The roast I was formally using was a proper medium but I guess the nanopresso is too limited and shots are just sour because the roast is too light for it.

With the medium roast I actually submerged each part in hot water to preheat it and used water off the boil to limited the loss of heat as much as possible so it was as hot as possible and it had a little effect but not enough and it was still sour. Same grind setting using full city and no preheating steps (because I gave up and I was just making a latte) and there it was a balanced shot with a really good finish. So I got a benchmark and I could play with it more but finally a decent shot.

Having the same issue.
What grind did you end up using for the decent shots?

I use exclusively the wacaco and a helor 101 grinder. I found that if you use around 8 grams of coffee and lightly tamp it flush with your finger, then use the screen/spout to drive it down further, I get pretty good results.