Sifting Coffee For Batch Brewers

To all the particle distribution wizards out there,

I’ve got a few question about sifting coffee, so I’ve heard of people sifting out the fines for filter coffee to help with blockages and was curious what were the experiences everyone has had with sifting.

Currently I’m having issues with our batch brewer (Moccamaster) constantly blocking up and forcing me to switch off the brewer before it overflows and turning it back on when the water levels lower. We are grinding our coffee through the EK43 around 8 o’clock with the blades being zeroed at 3 o’clock. Would sifting out all the fines help solve this issue?

Also has anyone noticed a dramatic difference in brew times and overall flavour after sifting?

Finally is there a specific size that should be used or would a plain flour sieve do the job?

Thanks, Steven.


what dose are you doing your batch at? i had this issue at my old store and the remedy was to dose lower.

Sorry i can’t be of more help!


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At the moment we are dosing 60 grams to 1 litre of water.

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I don’t have personal experieince with the Moccamaster but know quite a few owners//users. None have had the issues you describe. Makes me wonder… what grind particile size are you using? My guess is you are grinding too fine, and it is the massive quantity of fines that leads to the clogging. Try moving a few notches toward coarse, brew a test batch. If it doesn’t clog, taste the results… if its harsh, you could still move a bit toward coarse. If its thin and weak, your dose may be too small, or grind now a bit on the large side of things.

When I first began using the Curtis G3 batch brewers it took a bit to reach the happy point between dose and grind size to produce a smooth sweet cup, eliminate overflow/flooding, and economise on the coffee. Once sorted out, no issues. I do events, and have to brew a LOT of coffee over short tme periods. Could not do it without that G3 machine. Makes me look back and laugh at the days I did weddings etc (300 guests at times) with two mains=powered kettles and two 1.5 Liter Chambord French Presses, kept fed by my trusty Baratza Encore. (or, for the event before I got that, when the powered grinder smoked and quit, a hand crank Peugeot sheet metal sided Box Mill.

Thanks for your reply, so I had this same chain of thought as well and started to grind the coffee coarser. This gave me the exact problem that you described were my coffee had little body and tasted under extracted, especially when I compared it to the same coffee brewed through a V60 in shop.

My current thought process is that I might need to try sifting or that my batch brewer is not suited to do such large batches and that I should break them down into possibly two batches of 30g to 500ml water rather than one large 60g to 1L of water and risk the overflowing issue.

Steven, your response is interesting… I checked, and that Moccamaster is rated to brew a full 40 ounce US batch, almost 1.2 litres. On some models there is a three way switch to change rate of water flow… perhaps you could check that aspect. Don’t know where the switch is, but current models have them. Technivorm are well knwn for quality and accuracy. I highly doubt the machine is the problem.

Back to grind size… I don’t use the grinder you have, so the positions don’t help me know where it is set. I do know I want one, partly because they have a great reputation for consistent grind size. SO… how much did you change grind size when you made the adjustment? If you moved it quite a ways, it is likelyyou moved it too far, Try going back half of what you moved it. Your dose calcs at close to 17 : 1, right in the “window”.
One other thought comes to mind… have you switched brand or filter, or are you certain you are using a quailty filter? Folks i know who use the Moccamaster tend strongly toward the Melitta line. If you are using something else wiht too fine a weave, or that is too thick, it could not be allowing the brewed coffee to flow through.

Hope this helps. Troubleshoting from long distance is always a challenge… but here are some bits of data and some ideas to toss into the hopper for you.

Hi Steven,

Smaller batches and ensuring you’re using a porous-enough filter would help.

The problem IS the machine design; a Melitta-style cone is not ideal for 1 liter of coffee, as the bed depth is too deep with 60g of grounds. Those filters work well with 20g-30g of grounds; beyond that, you have to employ some tricks to produce quality extractions.

That said, you can succeed with a 60g/1L batch by grinding very coarsely (probably +/-10.5 on your EK), minimizing stirring to avoid fines plugging holes in the filter (but please still stir a little at the beginning and end of water dispensing), and putting COLD water into the Moccamaster tank. The Moccamaster doesn’t have flow control, but the colder the water in the tank, the slower it will dispense.

When everything is in alignment, you should be able to reach 20%+ extraction with a total contact time of about 6:30.

Best of luck



Thanks for the tips. What contact time do you recommend for 30g of grounds?

I typically use 27.5g coffee/500g water with my Moccamaster and the total contact time is around 4 minutes.

Hi Steven

Do you see lots of fines in the end of grinding coffee? My EK have a lot of fines n it block my moccamaster as well. Just curious do we have same problem