I have noticed this problem for quite a while and would like to see if any one has the same experience as well as solutions for it. I usually make 1-3 cappuccino (double shot for each cup) in one section, and I always grind all the beans I need for one section at a time (e.g. 2-6 spoons of beans for 1-3 double shot). The combination of the fineness of the coffee grounds and my tamping pressure produces good shot that I am happy with.
Occasionally, I will make coffee for 4-8 guests in one section. I put 8-16 spoons of beans in the hopper and then grind them at a time just like I do for 1-3 serve. However, I found in this case, the coffee grounds are finer than those that I grind for 1-3 serve (2-6 spoons). The result is that I usually has to toss the first or even the second pull which has really slow flow (1oz in 25sec) and then adjust my pressure of tamping to make the flow right (1.5oz-2oz in 25sec).
My guess is that when making coffee for more people, I put more beans in the hopper and the heavier weight from more beans causes different results from the same grinder setting. Am I guessing it right? Have any of you had the same issue when making coffee for few people versus more people? I do not want change the grinder setting because of occasional events. How do you deal with this situation? Any recommendation? THANKS!

BTW - my grinder is Cimbali Junior. Thanks again!

kuoyen wrote:
My guess is that when making coffee for more people, I put more beans in the hopper and the heavier weight from more beans causes different results from the same grinder setting. Am I guessing it right? Have any of you had the same issue when making coffee for few people versus more people? I do not want change the grinder setting because of occasional events. How do you deal with this situation?

Kuoyen, you've hit it on the head.
Usually, though, the weight of the grinds makes the pull a bit faster for me, rather than slower. I'd suggest that you reduce the amount of coffee in each basket for the time where you're making four to eight doubles for guests, or go ahead and make the grinder adjustment.

+1 on your guess, and previous posts. Hopper level definitely impacts grind.

Having to change up your routine under pressure is no fun. For most consistent results, pick a hoppper level and always use that amount of beans. If you generally make 3 or fewer doubles in a session, only ever put that amount of beans in the hopper. If you need to pull more shots than that, top off the hopper with another couple of scoops after you've ground the coffee for the first two shots. Repeat as necessary to finish your session.

Another possible explanation is Murphy's law. I find that any time I grind way ahead (more than 2 doubles) there will be some adjustment required that will throw off my pull. The universe seems to find this amusing. I guess someone somewhere wants me to grind on demand?

Ian - Thanks for the link. I tried search but did not see that one. Though the situation is slightly different, it's still very informative.

Psyd wrote:I'd suggest that you reduce the amount of coffee in each basket for the time where you're making four to eight doubles for guests, or go ahead and make the grinder adjustment.

Chris - Thanks for the advice. My question is that reducing the amount of coffee in each basket probably will make the flow correct, but will the quality/taste of the shot still the same since the shot is extracted from different amount of coffee? Thanks again!

BradyButler wrote:Having to change up your routine under pressure is no fun...

You are absolutely right... None of my friends invest their time and money like people on HB, and thus they usually watch every of my steps and want to know what magic my machines and I can bring to them...

BradyButler wrote:Another possible explanation is Murphy's law. I find that any time I grind way ahead (more than 2 doubles) there will be some adjustment required that will throw off my pull. The universe seems to find this amusing. I guess someone somewhere wants me to grind on demand?

I like the last "grind on demand" comment... it's probably the way to go! Thanks!!

Shifting grind as the hopper empties is a common thing. It is even more pronounced on big conicals. Dose per grind, fill the hopper with twice as much coffee as you need or grind it all at once and let the grinds mix in the doser. Any of the above will address the issue but the later options you need to quick on the drink making so the coffee does not die in the doser while you make drinks. I keep about a half pound of coffee in the hopper personally.

Do you grind and dose at the same time or dose after grinding? Does these two procedures make any difference, e.g. more even distribution, less clump? Thanks!

One more question for you, Dave. Would you mind recommending a fitted tamper for A3? Mine current one is Espresso Gear Barista tamper 58mm and it always creates residual grounds on the basket wall after tamping. Thank you again!

Dont worry about a few stray grinds on the basket wall. it has no effect on the shot. I have several tampers but the one I use all the time is a good old Reg Barber 58mm stock. Basket geometry changes between baskets. So if you get a custom fitted tamper for basket A, it may not fit in basket B, even if both baskets were made by the same company. Tamper fit and basket sizing variance has been discussed extensively. Try a couple of searches and you will get volumes of information on the subject.

I run a full, or fuller hopper so grind shift is not an issue. I dose while grinding.

Thank you, Dave.