Single Shot v Double Shot Linea Mini Baskets

Beginner and pro baristas share tips and tricks for making espresso.
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caddycatcoffee
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#1: Post by caddycatcoffee »

So I have seen lots of discussion on the difference between pouring single and double shots and because I don't have a great understanding on the science I wanted to ask and know this:

If you have a 14g and 7g precision basket and your 14g basket has twice as many holes as the 7g basket shouldn't the restriction be exactly the same if the grind size is the same and dose is exactly halved?

I keep hearing that channeling increases if you try and half your recipe and that you are allowing water to escape faster but it can only escape through the holes which is what causes the pressure from just building up in the basket. So also is there technically a number of holes that would match the same flow rate as a 14g or am I looking at this completely wrong?
I have rather large hands - James Hoffmann

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another_jim
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#2: Post by another_jim »

It's not so much science as custom. Single baskets are used in Italy, Mediterranean countries, and by people who treat it as their ordinary style of coffee. Double baskets are used in other countries where espresso is a style of specialty coffee.

If you dial in your technique using a single basket at 7 grams; you will be using a very fine grind and getting around 22 to 25 second shots. When you switch to the double at 14 grams, you will get a shot that takes around 35 seconds.

If you dial in your technique using a double basket at 18 grams, and getting shots at around 25 to 30 seconds, then switch to a single basket with 9 grams; you will get a channeling meltdown, regardless of how proficient you are at doubles. Since most hobbyists are doing shots this way; they have lots of trouble with singles.
Jim Schulman

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ojt
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#3: Post by ojt »

I think the channeling risk and finicky nature of the single baskets is due to the shape of them. The usual double basket or bigger are the same width all the way, keeping the water column trying to pass through the coffee also the same width. Imagine adding a pipe to another of same width. Water would flow "straight".

The single baskets instead are restricted, narrower in the middle or with sloped walls. This creates different flow dynamics, presumably passing more water from the sides of the orifice area, leading to potential channeling.

Does this make it more clear? Personally I don't need the single basket at all but a friend with the same machine changed from a single basket to double basket plus a puck mesh screen and said it is much better. Anyway, just wanted to try and explain the problem in simple terms.
Osku

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Jeff
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#4: Post by Jeff »

Another thing to think about is that it is the coffee grinds that provide most of the resistance to flow, not just the holes in the basket. With most styles of "single" baskets, the puck is thinner than that for a "double" basket. A thinner puck will often be more sensitive to poor puck prep and may need a different grind to get a reasonable flow rate.

The LM1 / VST 7 baskets take a different approach than many by effectively being a 41 mm basket that fits a 58 mm group. 41 / 58 ~ 0.707 ~ sqrt(2) so they have half the area of a 58 mm basket. For half the dose, you'd end up with a puck that is about the same thickness. 8 g or so in an LM1 with the same grind as 17 g in a VST 18 is close to dialed in. It still needs some tweaking, but it is drinkable. After tweaking, it is still different than the shot from a "double" (hard to say "better" or "worse"). My experience with other "single" baskets is that the grind size needs to be changed a lot, compared to a "double" basket.

Espresso is far from a simple, linear thing. There's all kinds of things going on that people are just starting to explore and come up with testable models and hypotheses for. It can be hard to sort out historical beliefs, unsupported opinion, wishful thinking, and tested hypotheses. It gets even worse when you start to consider that there are now believed to be two "sweet spots" for espresso, one around the classic 25-second mark, another in the 10-15 second range, and that light-roast espresso, especially with some of the modern, flat-burr grinders, is a very different thing than classic, medium-dark and darker espresso.

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caddycatcoffee (original poster)
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#5: Post by caddycatcoffee (original poster) »

Thanks for the info this is really helpful!

Would you say than as well that it is better with single shots to chase grind and not really touch your dose?

ie. right now I am working with a really fun Indonesian Bean that is Honey Processed from Coava - I tried replicating Coava's 19g in, 25g out in 25 seconds and channeling was always an issue (Puck was always prepped) as I went finer to deal with Gushing. I can't recall where I saw it but I knew that on some funky beans it's good to try dose adjustment for channeling at finer settings and I recently acquired a puck screen so I dropped my dose on my current setting to 16.5g and used a puck screen (doesn't fit unless its 17g and under - using a 17g basket instead of 20g because apparently Coava also overdose there basket) and the last four I got were wonderful 16.5 in 38 out - shots in 25 seconds.

Would you ever adjust dose or stick with grind size - yes I know there are no real hard fast rules and you should always be willing to push any of your numbers one way or the other for taste and preference but more as a rule of thumb?

Also has it been definitively decided if the F.3.053 (shallow) or the F.3.054 is better?
I have rather large hands - James Hoffmann

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Jeff
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#6: Post by Jeff »

Nothing is ever "definitively decided"!

I prefer the LM1 with the square sides, a Tidaka funnel, and a 41 mm tamper. One of my baskets was supplied through a third party as an F.3.029.

Others have opinions about what works best for them. For many of those people, I have confidence that they've actually tried them out and come to a conclusion that works for them. Several threads over the years, for example

What's the best single basket.
7 gram single shot?? Mission impossible!

With a single-dose grinder that really has close to zero retention (not just in-vs-out variability) and a smooth adjusting collar, my own practice is to work with grind alone in most cases. There are some super-tweaky profiles on a DE1 that I used to then adjust 0.1 or 0.2 g, but they were the exception.

If you've got a classic-design grinder, getting all of that last grind out can be a challenge. There I might consider adjusting dose once I was pretty close with grind.

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caddycatcoffee (original poster)
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#7: Post by caddycatcoffee (original poster) »

Yeah until the Niche arrives I'm stuck using my wife's Peak, up until 2 weeks ago (when I ordered it) I wasn't really allowed to make many changes/alterations to my wife's work flow when it came to dosing/baskets/ratios/etc. I get it, she's got an expensive set up and I really don't know what I am entirely doing (I would argue less so without the ability to experiment). Either way now that it's on the way I'm just trying to really understand single shots as best as I have so when it arrives I can start pulling singles (help have more fun pulling more shots and not get to over caffeinated) and that way I can start experimenting (Yes I know Niche has limits, but I can't justify buying a EG-1 at this time).

Appreciate all the info this is certainly helpful especially all the old posts, they are so informative
I have rather large hands - James Hoffmann