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I've been making espresso for a whiles now, but every once in a while I'll get a bag of beans that I just can't dial in. I was hoping someone could possibly explain.

My equipment is a Macap M7D grinder (Titan, Conical Steel burr grinder w/ an 800 watt motor) and a LM Linea Mini with upgraded slayer dispersion screen and brew pressure set at 6 bar. I have a bag of freshly medium roasted beans from Bali and roasted w/ a reputable roaster, brewed 6 days after roast date. Despite grinding 18 grams on my grinder's finest setting, meticulous WDT, and a level tamp w/ Decent tamper, the shot simply comes out too fast (~18 seconds/40mls). I made this shot 3 times to confirm it wasn't by chance a fractured puck, all with similar results.

My first inclination is that my technique is off some how and introducing channeling, but if that was the case how could I be so consistently off with this coffee and other coffees be consistently on point (relatively speaking). Also if you watch the video, the espresso comes out pretty evenly.

Any guess why? Could it be that the coffee is simply off some how? or that 18 seconds is an appropriate brew time for it?

I'd say it's the coffee, it blonds too quickly.

Maybe you need a Slayer.

Sometimes you just chalk it up to the coffee. You might also try changing your dose up or down just to see what happens.

Before any troubleshooting: have you tried the coffee? How does it taste?

What is the roast level of the coffee? I have had a few ultra light roasts that simply flowed ultra fast no matter what I did. That didn't necessarily mean they didn't taste good though!

What basket are you using? You could possibly opt to use a lower-flow basket for this roast if the higher flow rates are detrimental to the brew. I will say though that I often had better shots with fast flowing coffees in fast baskets than trying to make the time "right".

Lastly, does your grinder allow you to calibrate it's grind range? Due to fines production the zero point on conical grinders is not normally the point where burrs touch. If that particular coffee produces a lot less fines than others you might end up needing to grind below the "zero" point.

rrahman wrote:I've been making espresso for a whiles now, but every once in a while I'll get a bag of beans that I just can't dial in. I was hoping someone could possibly explain.

My equipment is a Macap M7D grinder (Titan, Conical Steel burr grinder w/ an 800 watt motor) and a LM Linea Mini with upgraded slayer dispersion screen and brew pressure set at 6 bar. I have a bag of freshly medium roasted beans from Bali and roasted w/ a reputable roaster, brewed 6 days after roast date. Despite grinding 18 grams on my grinder's finest setting, meticulous WDT, and a level tamp w/ Decent tamper, the shot simply comes out too fast (~18 seconds/40mls). I made this shot 3 times to confirm it wasn't by chance a fractured puck, all with similar results.

My first inclination is that my technique is off some how and introducing channeling, but if that was the case how could I be so consistently off with this coffee and other coffees be consistently on point (relatively speaking). Also if you watch the video, the espresso comes out pretty evenly.

Any guess why? Could it be that the coffee is simply off some how? or that 18 seconds is an appropriate brew time for it?

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you have explored what most would consider all the advanced techniques and seem to be fairly experienced. Of course, does the coffee taste good? cause if it tastes good then don't chase the time, chase the taste, perhaps change your ratio. Assuming you still want to get more out of the shots I would try and contact the roaster and see if they have anything to add or confirm regarding this coffee/roast. If you're still desiring longer shots then you have to try and slow the shots down. I know some use Aeropress filters to the top/bottom of the puck which helps to prevent fines migration and erosion of the puck. typically doing this has a product of speeding the shot up not slowing it down which allows you to grind finer (and I guess is not an option for you). however, adding the top filter only should help with the integrity of the puck and if there is a problem with it breaking apart that leads to increased flow then something like this may help correct the issue. You could also simply try and dose higher which might get your extraction time in a sweet spot. baskets are generally good for +/- 1 gram so I wouldn't worry about going up a gram (plus the only thing you can damage is the shot, so it's worth a try). dose up a gram (or even 2) and see what sort of impact that has on the time. Another thing that is claimed to slow down shots is doing a nutating tamp. most will tell you not to try it and it's difficult to do well and ultimately poor practice but perhaps you are not most people and it's something you might want to try. nutating tamps will compress the coffee more and has an effect of slowing shots. According to Hoffman's lastest video apparently giving the puck some sprays of water (a grams worth) is said to help with the pucks resistance which may help the issue you're experiencing. normally you would just grind finer but since that's not an option maybe it's time to calibrate your burrs or check them to see if they need to be replaced or not. no grinder is perfect, calibration is going to give you more consistency. finally, if every other coffee is fine then obviously there is a difference with this coffee so broadly speaking the coffee is the problem so some of these other things may help to fix it.

I know you said your grinder is on the finest setting, but the coffee could still be ground too coarse. I know the last thing you want to hear is that you need to buy something else.

Lighter roasts tend to have a much higher bean density when compared to darker roasts; i.e. lighter roasts must be ground finer if all other brewing factors stay the same (Temperature, dose, distribution, leveling, tamping, boiler pressure). So my suggestion would be do just that: keep everything else the same and only adjust the fineness of the grind. This will give you a more accurate indication of what the problem areas could be.
When you observe a more restrictive flow you're on the right track.


Since the lighter roast tends to be more dense (less soluble) they may require a bit more contact time (longer than you may have been pulling) in order to extract the heavier compounds and lead you to a more balanced shot (26-30 seconds). It's something to play around with! Practice makes perfect!