The LM 7g basket offerings are definitely confusing. I consulted GS/3 parts manuals going back to 2011 through the latest version, as well as the current LMLM and Strada parts manuals. I also checked LM USA's latest parts price list. Here are my conclusions:

115/A: Original low-quality 7g basket. I believe it's plain sheet metal, perhaps galvanized, definitely not stainless. I have two that came as OEM with GS/3s in 2009, one of which has the entire hole pattern way off-center.

F.3.029: Advanced Precision basket. Same manufacturer and process as VST, without laser QA scan (i.e., may not meet VST specs). Sometimes listed as F.3.029S. Listed in the LM USA price list for $13.08. There's also a F.3.029.X listed for $39.39. Way more than any other 7g basket. No idea what that one is.

F.3.053: "INOX Italian" Stainless Steel. Only shown in LMLM and Strada manuals. The drawing shows it to be shallower than the other 7g models. $18.69 in the LM USA price list.

F.3.054: Advanced Precision Strada basket. These are identical to VST baskets, including the laser QA scan. The LM price list calls it "precision scanned", and lists it for $27.59, slightly less than the VST price, which I think is still $30.

The one that intrigues me is F.3.053. The depression in the bottom appears to be very shallow, perhaps allowing use of a standard 58mm tamper. i think it may be a similar concept to the IMS "The Single" 9G basket, which just has a shallow round depression in the bottom and is designed to be used with a 58mm tamper. Of course, the Tidaka would be useless with any basket requiring a 58mm tamper. I've only found one source of the F.3.053 basket other than LM, a Canadian restaurant supplier called PartsTown.

BTW, the 2011 parts manual also lists 115/F and 115/A/S versions of the 7g basket for Faema and Swift, respectively. Odd, because the Strada manual says the 115/A is for Swift Grinders. I can't recall which one right now, but one of the manuals says the F.3.029 isn't compatible with Swift grinders. I don't know much about Swift grinders, but it's not clear to me how any of these baskets could be incompatible with a grinder.

Thank you for the links and the observations on the volume vs mass when estimating output. Not sure why Italian baristas only refer to volume, crema is clearly a confounding factor there.

Jeff wrote: With darker roasts, such as classic "espresso" roasts, extended preinfusion may bring out unwanted bitterness. I have found "no" preinfusion to provide better balance with US-style "espresso" blends than explicit delay for preinfusion.

I suspected the same. For myself, I will entirely skip pre-infusion from now on, when pulling singles.

I do have the 41mm LM single basket. If you have any other tips/advice, that would be great.
Do you think I should flow control, or just set a lowish pressure at the pump (7,8 bars) and keep it there for the sake of consistency, with my singles?

Thank you for the accurate recipe!!


Alsp, thank you for clarifying this about Espresso being a single shot in Coratia. The EXACT SAME happens in Italy, we call it caffè and it's rigorously a single shot of 6.5g-7.5g
Ordering a "doppio" is extremely rare and would get you a 14g dose.

I really like it this way, and now that I am in the US I miss such a "light" (caffeine wise) delicacy that we Italians consume all throughout the day at leisure.
We like to dilute our caffeine evenly throughout the day, and each time maybe change things up (a ristretto, a macchiato, cappuccino, a marocchino, a mokaccino, depending on the time of the day). Om a side note, this is similar to what happens with green tea in some Asian regions (it might have something to to with longevity and blue zones)

That's why I want to pull singles.

Glad to know that our Croatian neighbors are also following our culture in terms of Espresso

As we all know, in America and Australia gourmet coffee shops, you will be given 18-24g shots. I cannot do 3\4 of these a day and survive.

Good to hear it's working great and no longer a mission impossible!

Fun nerdy fact: Ever wonder why LM came up with the magical but seemingly random 41mm diameter (with their original basket at least)?

The puck in a 58mm basket that we all loved is cylinder-shaped and in school we learn that the volume of a cylinder is h*πr^2 (h=height,r=radius or half diameter). And the surface area of a 58mm circle is πr^2, so 3.142*(58/2)^2 = 2642 mm2. How about 41mm? It's 3.142*(41/2)^2 = 1320 mm2.

Notice the familarity there? 1320 is exactly half of 2642 (well almost) and it's not a coincidence at all. This means that 7g in 41mm basket and 14g in 58mm basket will have exactly the same puck thickness/height, and that 41mm is exactly half the 58mm basket, cylinderically speaking. Clearly some engineers at LM has given this some thoughts, and it is why I think it worked so much better compared to other baskets. Who knew high school math is actually useful in real life years later

Not sure if I am the only one thrilled by this 'discovery' but here you go and feel free roll your eyes

p/S: upon rereading the thread Johan mentioned this earlier in the thread too.

Here's a Q - assuming that the puck height is the same, are the number of holes in the basket proportionally less in the single vs the double? And what proportion? This leads to shot times - are they the same in both single and double?

I've read countless threads here on the single basket, and this one by far has been the best. Almost makes me want to reinvest in a single shot workflow. *almost*

You'll find that a small dose adjustment is necessary for most double-to-single conversions. With most baskets I find that the single dose is slightly greater than one-half the double dose.

Years ago, another_jim (Jim Schulman) posted a simple way to do this: make the ratio of the doses the same as the ratio of the hole areas. For example, if the single basket hole area is 55% of the double basket hole area, use 55% of the double dose for your single.

This assumes that the basket hole sizes and precision are the same, and the basket heights are "standard". It works best with baskets from the same manufacturer.

Another way to approach this without measuring is cut the dose in half and adjust the dose until the flow rates for the single and double are the same.