I am trying to pull shots using a single sized basket but I am having a great deal of difficulty with the resulting shot. It seems to me that I get channeling and the espresso quality is poor. I have a bottomless portafilter and at times this does spray a bit onto the counter. I have searched the forum and there is no real advice on using single baskets and preparing them for extraction. It does appear more difficult since the basket narrows and you need some head space between the coffee and the screen. So dosing and tamping is more particular it would seem than with a double basket. My successes thus far are lots of crema, 25 - 30%, however the taste is not sweet but more bitter. I have adjusted the grinder to give me a 25 second extraction with 30 ml of espresso and I do use a cooling flush with my Expobar Pulser. Currently the boiler pressure is set at 0.8 bar with the extraction pressure at 9.5 bar.

So any advice on using single filter baskets correctly would be appreciated especially in the area of dosing and tamping?

welcome.

What coffee are you using?

I pull singles with a similar class grinder. IMO, there is a no man's land where single extraction maybe problematic. That no man's land occurs on doses that initially expand to the shower screen and then shrink with extraction. Either grind a bit coarser and use more coffee or finer and use less coffee. Only taste can tell you which way to go.

Eric's group head thermometer is a must


BTW, I was born in Saanich on Vancouver Island. If you're anywhere near Victoria, be sure to check out Discovery Coffee.

Hi Robert, welcome again,
my personal suggestion to start is the following:
Get a La Marzocco single basket and a corresponding 41mm tamper. Grind the dose to a cup or simlar instead of directly into the basket. Fill the inner part of the basket but don't put in more than in the inner part can hold. Distribute in there, tamp lightly and start again until the dose is complete.
That should give you a reference point to try other methods and find the one you like the most.
Regards, Jan

Make a shot with your double basket and get it right. Weigh the dose. Measure the diameter of the hole area of the single basket, bd_New, and the basket you are using, bd_Old. Now use the new basket, same grind, at dose

New_Dose = Old_Dose * (bd_New / bd_old)**2 (i.e. squared)

With all due respect to the great basket hole purge of 2010, this works fairly well most of the time.

Jim's formula works for some single / double basket, grind /dose sets and not others.

Differences in basket height can knock the calculation into a cocked hat.

rst wrote:I am trying to pull shots using a single sized basket but I am having a great deal of difficulty with the resulting shot. It seems to me that I get channeling and the espresso quality is poor. I have a bottomless portafilter and at times this does spray a bit onto the counter. I have searched the forum and there is no real advice on using single baskets and preparing them for extraction. It does appear more difficult since the basket narrows and you need some head space between the coffee and the screen. So dosing and tamping is more particular it would seem than with a double basket. My successes thus far are lots of crema, 25 - 30%, however the taste is not sweet but more bitter. I have adjusted the grinder to give me a 25 second extraction with 30 ml of espresso and I do use a cooling flush with my Expobar Pulser. Currently the boiler pressure is set at 0.8 bar with the extraction pressure at 9.5 bar.

So any advice on using single filter baskets correctly would be appreciated especially in the area of dosing and tamping?

if using a doser grinder are the fingers set for a single or a double shot?
double shots normal need less then double coffee of a good single shot by weight
double shots always run fuller then single in most machines
start with coffee weight 7 to 8 gr.for singe and 13.5 to 15.5 for the double
move fine to coarse grind go 3 shots between setting changes note when going from coarse to fine
have grinder running so as not to clog the burrs.

hope this starts you on the right path

If after making the grind and coffee volume setting do not achieve the proper taste quality for the coffee you are using based on extraction

check with your machine and coffee roaster manufacturer for filter basket hole size, recommended water pump pressure, coffee water, temperature range

Well, I don't know if I can help you because I'm a newbie, but look my topic Photos of two shots in 24 hours... BIG difference. Just overdosing a little bit my single basket and with better tamping I got a big improvement in the single. You only need to take care and not allow the coffee to touch the screen as it will probably break your coffee block. To ensure that you can dose, tamp, put the PF in the machine and take it off to see if the screen hurts the coffee block...

Hope that helps.

Leonardo

Good evening.

I'm using the same grind for both, double and single basket.

With the double I take 15.5 gram and for the single basket 9 gram.
With a dosing time of 15 to 20 sec for the single shot I get a lovely espresso (double 20 to 25 sec).

Since I'm pulling shots with these timing I have never again trouble with shaking around with grind and dosing weight.

Regards
streezz