Hi,

I recently switched from the Isomac Prof Inox to the NS Grinta. It's not meant to be an upgrade or anything, NS forgot to ship the Grinta out to the dealer so we were given the Isomac to use in the meantime.

With the Isomac, I was grinding very close to the zero point (screeching, chirping noise correct?) and I could get 25-30s extractions with 2 1/5 full scoops of beans with the 7g scoop. The Grinta has 70+ steps and I am actually grinding slightly past the maximum setting which is 4. The grinder starts to screech somewhere past 4 as the collar makes one round and goes back to 1. The grinds also clump a lot more than the Isomac and I get significantly less output for the same input when I look at the volume in the basket. As far as I can tell, I am not distributing or tamping differently apart from WDT which I picked up from this forum. It is impossible to get a level tamp without WDT with the level of clumping this thing produces.

I know the Isomac has reported problems with not grinding fine enough, but I've never read anything like that about the Grinta. Is the grind fineness the problem or is the problem with the guy holding the portafilter? Thanks.

The Isomac is an awful grinder, and its screeching is no surprise. The Grinta has serious issues with the bean and grind feed, but the motor and burrs are decent. I do not remember having to grind near the zero point with it.

Very old, stale coffee can require excessively fine grinding

Thanks for the reply Jim.

The shop I buy from carries 2 brands and I am using the 2nd of the two for the first time although they should be of similar freshness even if neither of the two is good enough as far as freshness is concerned. Would stale coffee explain the difference in output volume? From my observation both grinders have serious problems with the output chute design but I can't really see how much coffee the Grinta retains, could the volume difference be explained by the retention in the chute?

It sounds like you may be single dosing -- spooning in the beans into the grinder throat without having the hopper in. I'm a proponent of this in general, but never with the Grinta, which will hardly feed even with a stack of beans in the hopper.

If that is not the problem, try WDT and see if this improves things. If it does, it is your problem -- you have channeling. Get a bottomless PF and improve your distribution technique.

If neither of these do it, the coffee is probably stale.

I only put beans into the hopper as I need them. I have been using WDT ever since I got the Grinta because of the excessive clumping. Anyway, I will run through this batch of beans and go back to my normal ones and see if it makes any difference. Thanks for all your help!

Thanks for the link. They do stick together somewhat but I'm not sure what level of "stickiness" is correct, I never tried this with the Isomac when this wasn't a problem. The shots just gush out and I'm near the zero point so I guess they just aren't fresh then. I had no idea stale beans could cause this much variation in the pour, I thought it was more of a taste thing.

Anyway, thanks to the both of you. I'm going back to the original blend I was using and hopefully that will solve my problems.

You will never get anywhere unless you are sure the coffee is within 14 days of roast maximum. Is your coffee that fresh?

Possible explanations and solutions:

1 - Explanation: your grinder is not suitable for "grind only a dose at a time" style grinding. Solution: fill the hopper and see if this solves it.

2 - Explanation: you're working with stale coffee. Solution: buy some roast dated coffee that has a roast date within 5 days.

3 - Explanation: the burrs in your grinder are old or damaged. Solution: replace the burrs.

4 - Explanation: your shot prep (dose volume, distribution, tamp etc) is flawed enough that you're having to dramatically restrict flow through excessively find grind and this grinder simply cannot grind that fine. Solution: improve your shot prep

I think it's probably a combination of these.
If I had to sequence these in terms of likely contribution (from most significant to least) I would rank them as 4, 2, 1, 3.

I am not sure how fresh the coffee is, but it is most probably between 2 weeks old and a month. It is very difficult (I don't know if it's even possible) to find freshly roasted coffee in Malaysia, the coffee is imported from Singapore. I have switched back to the first of the two blends that I have used, I am now on the blend that worked perfectly on the Isomac the first time I bought it, I don't think it should be any less fresh but I can't be sure.

1 - I tried filling the hopper, this made no difference to the end result but I did get significantly more volume in the basket and it may have been a little bit finer but no progress with the shot time.

2 - Definitely not fresh coffee but I don't believe there is anything more I can do in this area. Anyway, I have gotten significantly better results with equally stale coffee when I was using the Isomac so I don't think this is the worst of my problems?

3 - I doubt this is the problem unless they got damaged in transport. The grinder is brand new and it's only usage prior to this was the demo done in the shop where we were given a walkthrough and lesson on how to use it. I distinctly recall the shot made in the shop gushing like mine and blonding early but the coffee wasn't levelled before tamping (I suppose he was in a hurry) and I've been using WDT and NSEW before tamping.

4 - Very possible, my skills are far from perfect but I was getting much, much better results with the Isomac and I can't think of anything that I've been doing differently.

I am going to contact the shop and see what they have to say about it. I'm really hoping there is something wrong with the grinder itself as I'm running out of options.