Not sure where to go to learn what I'm looking for other than here in the lever forum regarding innovations and techniques being used in the basket. I've been pulling a lever for many years but have questions about the relevancy of some practices for levers, specifically high end baskets like wafo, paper disks under the puck, and SS disks on top of the puck.
I'm currently using a 10 year old VST basket in my Cimbali M20. I get very uniform extractions and I like the taste. With levers, unlike the new pump machines that allow temp and pressure profiling, my temp is set by the boiler pressure, my pressure is set by the spring, and my volume is set by the piston. I don't use light roasted coffee. I realize that putting a disk on top of the puck could help with keeping the group head clean. But with the set parameters of a lever are there any advantages to high end baskets or paper under the puck?

With an e61 HX I used for many years a lot of gunk caked on inside the showerscreen over time. With the Strega lever I have now after recently pulling out the piston to lube the seals after about 6 months there was almost no build up. Don't know about other levers but I'm under the impression that's pretty common.

The Strega is a pressurestat controlled temperature surfing and lever controlled preinfusion/extraction pressure machine. With an IMS showerscreen, VST and Barista Pro baskets the shots are so good I don't consider basket filters or screens. I can't even say how much difference the showerscreen or baskets really make since I used them early on when I was still getting to know the Strega.

My levers many years before the Strega were a springless Cremina 67 and Europiccola. No changes from stock except naked portafilters. The control with them and the extraction quality is what pulled me to a bigger commercial grade lever.

bgn wrote: I don't use light roasted coffee. I realize that putting a disk on top of the puck could help with keeping the group head clean. But with the set parameters of a lever are there any advantages to high end baskets or paper under the puck?

My impression, from reading and personal experience, is that the sort of "advantages" available from high end baskets are suitable only for users of light-roasted coffees, from which it can be difficult to obtain sufficient extraction. Not only are high-extraction devices not needed for medium- and light-roasted coffees, they can be counter-productive as the additional extraction yield (EY) from such coffees can contain unpleasant flavours.

kalo925 wrote:Have you seen this video? They talk quite a bit about paper under the puck. video

I have not. Thank you.

mathof wrote:My impression, from reading and personal experience, is that the sort of "advantages" available from high end baskets are suitable only for users of light-roasted coffees, from which it can be difficult to obtain sufficient extraction. Not only are high-extraction devices not needed for medium- and light-roasted coffees, they can be counter-productive as the additional extraction yield (EY) from such coffees can contain unpleasant flavours.

Those were exactly my suspicions. Thank you for your thoughts. I'm expecting an Odyssey Argos (someday!), and I think it might ship with a SS disk for on top of the puck. I've never used such a thing but will be interesting to try on my existing machine as well.

Worth a try for sure.

With light roasts I grind a little finer, hold for line pressure 10sec+ preinfusions then use Strega's pump to fill the grouphead and start extraction before letting go. The spring pressure start is around it's peak for a long ramp down extraction which I think pulls out more of what the light roast has to offer. A long circa 2bar line pressure preinfusion I think gives the puck time to well saturate and prep the solubles for a full spring pressure pull. The pucks consistently come out even coloured and dry. The extraction taste is consistently and repeatably complex and good.

It all works so well I'm not inspired to experiment. It's worth trying but in my experience baskets, screens and filters might be factors but not deciding ones.

mathof wrote:My impression, from reading and personal experience, is that the sort of "advantages" available from high end baskets are suitable only for users of light-roasted coffees, from which it can be difficult to obtain sufficient extraction. Not only are high-extraction devices not needed for medium- and [dark]-roasted coffees, they can be counter-productive as the additional extraction yield (EY) from such coffees can contain unpleasant flavours.

Even if you don't want to push the EY it still seems advantageous to extract evenly.

The thing I wonder about is whether the higher concentration of solubles in the outer parts of the puck really represent underextracted grounds instead of pooling of fully extracted solids from higher in the puck. How can you tell the difference? If it's the latter then the only advantage to getting those into the cup would be an economic one.

I personally am not interested in a paper filter below the puck for the simple reason that I like the undissolved solids in espresso. It also seems like a kludge to use paper to make up for baskets that don't have holes extending to the edge. Why are they typically made that way? Is it a manufacturing limitation or is there some other reason?

Good question about the baskets.

There's also the straight or tapered advantage.

Before my Strega there was an extraction hit and miss with my rotary pump 9bar E61 HX. Extraction along the edges might have been a factor relative to even showerscreen water flow and full basket water infusion/saturation. I had to be really good with puck prep and still the extractions were never as consistently good as the lever.

The E61 had a short preinfusion and was capable of longer plumbed in line pressure preinfusion which I never really experimented with. Stock showerscreens and baskets tended to lack precision as well but the biggest factor I think to extraction quality was hitting the puck with little preinfusion at 9bar pressure. Regardless of how well the puck was prepped uneven extraction and channeling was easier with a mostly dry puck. The paper filters and screens I think offer the resistance to slow down initial infusion to allow the puck to get the full saturation with machines that don't have active infusion and extraction pressure control.

There's also that dot in the middle of a showerscreen. I'd think even showerscreen holes all around would be the better way to go but the video's reference to overly extracting at the center of the puck kind of makes restricting extraction at the center a good idea. My showerscreen has that dot, my pulls go center stream and taste good. I've wondered whether the no dot IMS showerscreen would be a better option. Maybe not.

Now I'm interested in what the practical improvement raining down shots would be over center stream. Don't want to have to save up months of allowance money to afford a basket that might give me those extractions, though.

jpender wrote:Even if you don't want to push the EY it still seems advantageous to extract evenly.

I would have thought that extraction evenness comes mainly from a good grinder and good distribution. Unless your basket has a truly terrible hole assortment - some holes not punched fully, others ragged and of varied sizes - the extra holes in the billet baskets wouldn't be needed to reduce unevenness, which mainly arises from channeling.