Dosing confusion

[pgseye]

Hi Guys,

I'm becoming a little confused over how to balance grind size and portafilter dosing. I have a Pesado 20 gm (I think) basket.

Essentially you want the basket about 4/5 filled so that the bottom of the showerscreen just touches the top of the tamped coffee, correct? Overfilled - not good, underfilled - not good.

But you're also grinding to a weight - say 18-20 grams. Won't the particle size of the grind (to a fixed weight) affect the volume of the basket filled (or am I missing some basic physical principles of matter)? If that's the case - how do you balance between weight and volume? Or does one really just grind to weight, while optimising the grind size, but not worrying about the resultant level in the portafilter?

Hope not a dumb question.

Thanks,
Paul

[blend52]

Every one will have a view on this, so just take this as "my take"..
Dose weight is an outcome of getting the grind size and dose volume (filter basket load), correct for any particular bean.
Weight will vary from different beans/ roasts, age etc.
Forget weight to start with.
Aim to keep the filter "fill" level consistent by over filling with grinds, settleing, scrape level, then tamp.
Do that consistently each grind, and adjust the grind size to give the 25-30 sec extraction.
Once you get consistent results, you can do a empty/ filled weight check on the basket to establish the dose weight for that particular bean batch.
Be prepared to waste a few shots to get this correct.

[Wushoes]

Every one will have a view on this, so just take this as "my take"..
Dose weight is an outcome of getting the grind size and dose volume (filter basket load), correct for any particular bean.
Weight will vary from different beans/ roasts, age etc.
Forget weight to start with.
Aim to keep the filter "fill" level consistent by over filling with grinds, settleing, scrape level, then tamp.
Do that consistently each grind, and adjust the grind size to give the 25-30 sec extraction.
Once you get consistent results, you can do a empty/ filled weight check on the basket to establish the dose weight for that particular bean batch.
Be prepared to waste a few shots to get this correct.

That's a pretty wasteful way of making coffee there. If it's rated for 20 grams, it can accept +/- 1 gram. Weigh the dose on scales and adjust grind accordingly. Don't worry about how much headspace there is. Tamp, extract. Even if the puck is sloppy, if it tastes good then go with that.

Always set your dose. Lock that in - don't change it for now. Then I recommend brewing to three ratios 1:1.7, 1:2.0 and 1:2.5 all in a time of around 28-30 seconds. Pick a favourite ratio/yield and refine from there.

If you're worried about sloppy pucks, time to dose up slightly, then repeat the whole process. The ratio you picked earlier should be similar if not the same with this new dose.

[Wushoes]

Just to further clarify, when I say headspace doesn't really matter, just make sure you don't overdose the basket.

[mwcalder05]

In my opinion and in my experience of making coffee in a cafe for 3 or so years, I'm with Wushoes. Weigh your coffee full stop. It's something which you can repeat over and over and over again easily. I'd go so for to say: forget about the state of the puck apart from channeling. If you've got a 20g basket, you can generally get away with 10% of that weight over or under but do that weight every single time and just change the grind. In the preparation of the shot, the grind should be your only variable that you need to change.

[BeanBrat]

I agree with Blend52.

I ensure the volume of the ground coffee is at the ideal level, rather than focusing on weight.

A little experimentation has taught me the ideal dose for my portafilter/basket/machine, the fine tuning is performed by slight variations to grind and the tamp pressure. I waste very little coffee and I rarely pull a shot which is not to my liking.

My Pullman tamper has rings running along the base (I believe these are called TrueTamp rings), I found these to be helpful to standardise the level though I barely glance at them now.

I have used standard, VST and Espresso Part HQ baskets .... my choice is the Espresso Parts HQ basket.

Please don't take this as a plug for Pullman or Espresso Parts baskets but these have worked well for me. I plan to purchase a Pesado basket in the future as they do look like a premium product.

My Elektra machine is superb but is a little sensitive to overdosing so I have had to learn to be cautious with volume, grind and tamp ... weight is a factor I don't consider.

[DesigningByCoffee]

Ahh, these threads are funny

pgseye, for what it's worth, I'm constantly using all methods listed above!
When I'm doing an event I used timed dosing on the grinder. Or sometimes I just eyeball it manually if things are slow. But I also now weigh to the gram when single dosing the Lido or Robur at home. USe someone else setup, I just go by eye. These all give pretty good coffee - 98% of the time

But using any of these methods, you should end up with a level where the coffee, when tamped, sits just above the level of the spring clip groove in the basket (if it has one). It shouldn't touch the screen when the handle is locked in place (or you will mess up the top of the puck and risk channeling) but after the shot there should be an indentation showing the screen outline.

If, when you've done this, it is pouring too fast, fine up the grind a little (and perhaps add a fraction more coffee to compensate for the greater settling.) Too slow - vice versa.

All the best!
Cheers Matt

[Dimal]

As an aside to the comments above, I've always found that slightly so-called underdosing, regardless of filter basket size, produces sweeter and more interesting results in the cup, nine times out of ten.

For me at least, I guess that this translates into optimum dosing...

Mal.

[pgseye]

Thanks for all your input guys. There doesn't seem to be one way to do this, and I feel reassured by that I guess :-)

[AlMac]

What you want is a consistent method.
If you don't like the output, change only one variable.
Even if you don't follow what Wushoes said, at least take away having a process. Matt also gives you a process, just a different one.

I would:
not overdose;
have a consistent method for how much you fill the basket, how much you wipe off pre-tamping (I use the same tool each time), how many times you tap the PF to settle the grinds and how hard (once gentle/firm should do it), how hard you tamp. If you get this down then you should be able to fill the basket consistently within 1g or so each time;
do something with shot weight/ratio as Wushoes suggests, or follow Matt's suggestion, to work out what you like (best ratio is the one you like); and
adjust grind to suit, keep everything else stable.

If that doesn't work, then look for another variable to change. I would then start with over/under dosing as my next variable.

[patrizio]

I agree with Wushoes and Almac about grinding according to weight. This ensures your doing the same thing each time which reduces the variables in each shot so you can concentrate in dialing in that perfect shot.
To add my theory to this
sometimes I find people run around in circles because they forget that the coffee grind between the blades and dose spout contains some residual coffee grinds so when you adjust the grind size you should grind for a minimum of 5 seconds and dump that coffee grounds which contains a mixture of old grounds size and new ground size.

After you dump do a least 2 shots before you change the grind size this will ensure you have the current size setting in your basket and should be a similar shot each time for yield within that 25-30s time

If this step is not followed once they find the perfect shot when they go to repeat the shot it has changed and they start again to chase that perfect shot and you end up spinning around in a circle chasing your tail.
I hope that helps

[pgseye]

I agree with Wushoes and Almac about grinding according to weight. This ensures your doing the same thing each time which reduces the variables in each shot so you can concentrate in dialing in that perfect shot.
To add my theory to this
sometimes I find people run around in circles because they forget that the coffee grind between the blades and dose spout contains some residual coffee grinds so when you adjust the grind size you should grind for a minimum of 5 seconds and dump that coffee grounds which contains a mixture of old grounds size and new ground size.

After you dump do a least 2 shots before you change the grind size this will ensure you have the current size setting in your basket and should be a similar shot each time for yield within that 25-30s time

If this step is not followed once they find the perfect shot when they go to repeat the shot it has changed and they start again to chase that perfect shot and you end up spinning around in a circle chasing your tail.
I hope that helps

That's actually a good point patrizio. I had wondered about how much to purge between grind size changes.

[Yelta]

Ahh, these threads are funny

Guess it's a process we all go through, the subject keeps recurring like a bad dream, there must be enough written on this journey of discovery in the CS archives to fill a large volume.

Once the penny drops all is well, of course in some cases it simply never drops.

The issue ain't that complex, a bit of thought along with a some help from friendly others usually gets things sorted quickly.

My single tip pgseye is to only change one variable at a time, you'll get there.

[kbilleter]

As an aside to the comments above, I've always found that slightly so-called underdosing, regardless of filter basket size, produces sweeter and more interesting results in the cup, nine times out of ten.

For me at least, I guess that this translates into optimum dosing...

Mal.

I'd agree there and roughly agree with attached image. (I'd like to attribute it but can't remember where it was from. Google image search will probably turn it up but too much work on the mobile on the run :-) )