Inconsistent Espresso Shots with New Niche Zero and Rancilio Silvia - Looking for Help/Advice

Beginner and pro baristas share tips and tricks for making espresso.
Personability

#1: Post by Personability »

Hello,

I'm experiencing inconsistency with my shots, despite using the same puck prep technique. I'm currently working with a new Niche Zero grinder, which I've had for about two weeks, along with some new (roasted approx 14 days ago) coffee of "espresso" roast.

For my puck preparation: spraying, grinding, WDT, OCD distributor, and tamping. I spoke to Niche and, as per their advice, I have tightened the burr bolt, cleaned the grinder and made sure it is calibrated. I'm aware that new grinders need "burr seasoning", but I'm not sure if that would contribute to inconsistencies between subsequent coffees or if it only affects consistency over a longer period of time?

My espresso machine is a Rancilio Silvia without a PID, so there could be some temperature fluctuations at play, which I've been trying to manage by temp surfing.

What confuses me is that my first 2-3 shots can differ by up to 10 seconds, even with the same grind settings. After those initial shots, the following few shots (still with the same puck prep technique) land in the 28-32 second range. This is with that same coffee.

So, I have a couple of questions:
1. Could this inconsistency be down to the grinder? I was aware that the Niche Zero is generally regarded as a great and consistent grinder, but I suppose I was expecting it would dramatically improve my workflow. I just want to make sure that I didn't get a dud and need to send it back for a return.

2. Could it be possible that these inconsistencies are unrelated to the grinder and are actually due to subtle variations in my technique or the temp surfing?

I know there are a lot of variables at play here, and any advice or suggestions you could offer would be greatly appreciated! I'm eager to get to the bottom of this so I can start pulling more consistent shots. Thanks in advance!

KKUK

#2: Post by KKUK »

I had this with my Niche and I attribute it to exchange. The grinder retains and exchanges some coffee every time it is used so your first shot of the day includes coffee that is a number of hours old. Same story if you change grind size (particularly if you are going between espresso and filter).

The workaround is easy, grind and discard 5 or so beans at the beginning of each session. You should also do this when making adjustments to grind size.

Cranked

#3: Post by Cranked »

Hi, are you weighing your doses and shots?

Eric

Personability (original poster)

#4: Post by Personability (original poster) »

Hi. Would this occur with the first 2-3 shots? Makes sense with the first one for sure. I'm guessing it wouldn't account for the variation between same-grind subsequent shots?

Yep weighing 20g in 40g out and using the timing of this.

KKUK

#5: Post by KKUK »

Potentially with a new grinder - I find it takes a while to rid themselves of shipping static so there may be a larger amount of grinds retained. Have you seasoned the burrs at all?

This will settle down over time.

Personability (original poster)

#6: Post by Personability (original poster) »

I've run about 1.5kg through it so far. There was a ton of static initially but that's eased off a bit now.
To be fair, it does seem to be relatively consistent for a few shots but then go out of whack again after that.
Is my pick prep likely to be an issue instead?

User avatar
Jeff
Team HB

#7: Post by Jeff »

Despite the "zero" claims, the real-world exchange of a Niche Zero is around 0.3 g if you don't do anything. Depending on how long that has been in there, how much more or less you get out, and if you've changed the grind setting, that is enough to change the character of the shot. Two options that I have used include the bulb from the "ASPECTEK Safe and Practical Insect and Ant Killer Powder Duster." and the Fanwer "Palm Chest Percussion Therapy Cup" The Aspectek has more volume to its puff, but the pleats make it harder to clean than the Fanwer. Both worked well for me.

On prep, "less is more". The more steps you add, the more chances you have for variability. I'd avoid spinny-spinny tools of any sort as they don't do much of anything other than make your puck look pretty. They have the potential of making things worse if the bed isn't completely level to start with. A good WDT tool like the original LeverCrafft or the JKim Makes variant that innovated to be mailable in an envelope can quickly and easily both homogenize the grinds and level the bed.

At 1.5 kg, the burrs are probably starting to settle down. There may be smaller changes over the next 5-10 kg, but they generally should be consistent.

coyote-1

#8: Post by coyote-1 »

KKUK wrote:I had this with my Niche and I attribute it to exchange. The grinder retains and exchanges some coffee every time it is used so your first shot of the day includes coffee that is a number of hours old. Same story if you change grind size (particularly if you are going between espresso and filter).

The workaround is easy, grind and discard 5 or so beans at the beginning of each session. You should also do this when making adjustments to grind size.
So much for effortless workflow lol

KKUK

#9: Post by KKUK replying to coyote-1 »

I do this with my P-64 too. I prefer the workflow of the Niche but the coffee from the Lagom is so much better.

User avatar
cafeIKE

#10: Post by cafeIKE »

I puffed my Niche for a while after I re-entered the H-B swamp after owning the Zero for a couple years since the initial IndiGoGo run, but find that for the coffees I use, it's a non-issue. Retention varies from a light dusting to about ¼g. Every so often, I give it a puff just to see if it makes a difference. IMO, unless you are curating your beans to achieve better than one-tenth gram dose variance, it's a WOFTAE.

What basket are you using for a 20g does in a Silvia?