Single Dosing Compak F10 vs Pharos

Grinders are one of the keys to exceptional espresso. Discuss them here.
jvspin

#1: Post by jvspin »

Hello, I've been reading this site for a while but this is my first post. I've been using a Salvatore automatic espresso machine and Pharos grinder for the past year. I found a good deal on a Compak F10 so thought I'd give motorized a try. Single dosing is handy as I switch between decaf and regular though generally stick with the same coffees.

Using the Pharos, I was targeting 14g in 30s and got fairly consistent results. I was unable to get a 14g/30s extraction on the F10 regardless of how fine I ground. Comparing the grounds with a binocular zoom microscope, it was clear that the grounds from the Pharos were more consistent and the grounds from the F10 had larger pieces.

Further experimentation showed the larger pieces from the F10 were coming at the end of the grind. However, when the F10 grinds with beans in the hopper the grounds looked more consistent than the Pharos and the extractions were likewise more consistent, ie. more consistent time/g and more even extraction when viewing the bottomless portafilter.

Note, I'm grinding straight into the portafilter with the F10 then tamping. With the Pharos, I'm transfering the grounds from the catch cup into the portafilter, tapping the sides to even out the grounds after removing the funnel, then tamping.

These results make me wonder how the other single dosing motorized grinders would do if you were able to have more beans than needed in the feed versus grinding them all.

jgood

#2: Post by jgood »

I believe this is the problem with single dosing a grinder that is designed to work with a hopper full of beans -- you can do it but the results are not always so good. One possible approach is the small hoppers with a weight on top like those made by Orphan Espresso.

jvspin (original poster)

#3: Post by jvspin (original poster) replying to jgood »

I made a small hopper for the F10 but didn't try adding a weight. How do the single dose hoppers get around not having weight on the beans?

brandonbrewmaster

#4: Post by brandonbrewmaster »

When you say that you can't grind finer on the F10, are the burrs touching and chirping? Is your end weight 28g? What time are you getting with the F10?

jvspin (original poster)

#5: Post by jvspin (original poster) replying to brandonbrewmaster »

The burrs weren't touching but it got to a point where grinding finer wasn't making much of a difference. I don't remember what the time was for my target of 30g in the cup but it was much less than 30s. I could see the uneven grind when viewed with my microscope. This was done by putting a single dose of 14g in my modified single dosing hopper, running until all the beans were ground then using a baffle to blow any residual grounds out.

With beans in the regular hopper the grounds looked very even and the machine choked. I then had to set the grind coarser to get a 30g/30s extraction.

Charlie M

#6: Post by Charlie M »

Single dosing on my Compak E10 without a weight, I found that I had to grind a little finer in order to achieve the proper timing. I was grinding at a setting of 15 with no weight. I've since gone back to using the Orphan Espresso weight and am now grinding around 25. Am still dialing in a bit from the workflow change. With the weight, the grinds also look more fluffy, without small clumping, compared to when not using the weight. Performing RDT without the weight does not help with the clumping either.