I know everyone talks about the theoretical weight of a double as starting at 14 grams and going up to 18 grams or so with overdosing.

My question is about the volume the grains make in relationship to the weight.

My portafilter has 17 grams which does approx 25 seconds with first drips at 7 seconds. If I reduce the amount of grams to let's say 15, I won't be even near the rim at the start ? In so many videos, I see people overfill the basket and "push" off everything to make it even with the top of the rim. If I did that I would be approaching 18 grams. If I go less than 17g I will need to grind finer to get 25 seconds out of the shot ? I am a bit confused

17 grams does 25 second double shot


This is straightened but not pushed down (just below rim)

I don't usually weigh my coffee before I pour but when i have before its been 18 grams But I tried 17grams now to see how it went but without an espro tamper I think i tamped too lightly.

Straight from the grinder, doserless anfim. I tapped the basket on the surface before i leveled


Leveled pre-tamp and 17grams


Missing the Espro


I think this was down to a light tamp, slightly too fast. 20 seconds


Results.


Find 15 mins of spare time and just play with your grinder/tamp till you get a shot time that works for you. Doubt that helps much,but the topic gave me an excuse to make another latte, haha!

David,

I love photo's. This one shows a stream that I would like to know something about. Did it stay consistent like this speed which for me is a nice flow rate and less than I am doing. Mine goes a bit faster !!

That wasnt my best tamp of the day, its gotta be said. So it was slightly uneven. The stream closest to the camera went a bit wide when i took that picture but the one furthest from us stayed the same throughout. At the very beginning of the pour it was a very fast drip/slow,thin pour for about 3-4 seconds then took the form of that thin stream.

But the pour did not get any faster then what you see in the picture.

Thats what I want, but at that rate of speed, I don't think you are getting a full shot at 25 seconds are you ?

I calibrated my grinder while using a espro tamper. that way it always gives 30lbs pressure so it takes out 1 of the things that could be going wrong. I leave my beans for 7-9 days then test. I have a number range on my grinder that work depending on freshness so i only slightly adjust from time to time.
My usual shot time is 25 seconds but sometimes i like to take 35 for color with latte art. That pour in the picture was slightly too fast. what time are you getting currently?

Well I get 25 seconds, but thats because I stop at 25 seconds, not necessarily thats when the blonding or thinning of the shot.

I start and wait about 7 seconds where I get a stream right away thats nice (not drips that develop into a stream but directly stream) and it has nice color, but gets a bit thin looking and stream that widens by 18 seconds out.

It does taste good, and there is cream and it does have that red browny color, so I'm not far off the mark. My big question is that I am around 17g and not even coming up to the rim loose. I see so many people overfilling their baskets and then swiping the top even to the rim and tamping without measuring weight and it would seem to me that they might even have 18-20g in there.

I too am using a Acaso Automatic Tamper at 30lbs so I'm consistent there too. Fresh roasted Indian Arabica 100%. I tried Italian but it was too bitter ? I also tried Blue Mountain and that was equally good. I drink only Caffe Latte's not too strong. I'm in Italy all the time on business and even picked up my Vibiemme in Milano about 10 days ago so I know about Italian Espresso's and am just trying to recreate what I can have in any bar in Italy.

Probably worth perusing the FAQs and Favorites.
This topic has been discussed at length in various forms in the past.

To summarize:
1 - different baskets hold different volumes
2 - different coffees have different weights per volume (or vice versa)
3 - different grinders create different (uncompressed) volume by weight (per coffee)
4 - different coffees prefer different volumes (compressed)
5 - different machines have different high limits on volume (compressed)
6 - different combinations result in a range of double dose weight from as low as 12g to as high as 21g. all work.

To wrap up:
1 - don't get hung up on the weight or the volume (except in terms of consistency). Taste the results, adjust. The goal is in the cup (not on the scale).
2 - weighing and measuring is valuable in understanding how you got to a good result in the cup - but doesn't help you get that result.
3 - weighing and measuring does help you train to be consistent (and thus get good results in the cup in a more repeatable manner).
4 - with practice, you should not need to weigh or measure.
5 - the same goes for time.

I had a very similar question...

When I dose, I grind into the portafilter and then level with a straight edge... now I have not tried weighing the result, but if it is more than 14g (or any other weight I want to try) how would I straight level if the grinds are lower than the top of the portafilter?

14g is classed as a double shot, the 17-18g shot we are talking of is called updosing.
14g should not reach the top of the basket, or at least it hasn't with any baskets i've used. But when you dose try to make sure its in all the edges of the basket, nice and evenly spread and once you have your mound on top of the basket just tap the basket on the work surface then level and tamp.

You will only be able to fit in "X" amount before your group head disturbs the ground when you load it into the machine. you will need to find what that X amount is with 20 mins, spare coffee and a scale.

P.S.
just read over your post again and i think i misunderstood you at first, When i do a 14g shot i just level it by properly dosing and giving the bottom of the basket a nice tap on the surface.

malachi wrote: 2 - different coffees have different weights per volume (or vice versa)

Hey Chris, I'm curious about this one- have you observed any general rules for this weight/volume relationship?

I guess it would be more of an issue for people who empty the grinder for every shot then those who dose by volume with a full hopper.

Regards, Henry

davidr88 wrote:14g is classed as a double shot, the 17-18g shot we are talking of is called updosing.

incorrect. all shots produced using a double basket are double shots.
with some coffees, some baskets and some machines - 14g is a "mid point" dose.
with others, 17g is a "mid point" dose.

beware dogma

hbuchtel wrote:Hey Chris, I'm curious about this one- have you observed any general rules for this weight/volume relationship?

Nope.

Haven't explored this yet - just rough theories.