Puck paper purveyors? - Page 4

Beginner and pro baristas share tips and tricks for making espresso.
GDM528 (original poster)

#31: Post by GDM528 (original poster) »

Jeff wrote:The following applies to bottom filters:

Apparently the Pullman 875 baskets fit 2.25" punched drip coffee filters

For VST baskets I use Ahlstrom filters that I purchased in the US through DSC (DSC Balances, Data Support Co., and a few, similar variants). They weren't terribly expensive for product or shipping and didn't have a minimum order in the hundreds of dollars. I have the 2370-0550 and the 9090-0550 which are both relatively "slow" papers, 3 µm retention, in the 55 mm size. I don't know that the "wet-strengthened" ones are needed. An Ahlstrom catalog can be downloaded.
Thanks for the link! When you say "slow", do you mean they would noticeably slow down the flow rate? That would add an interesting dimension to engineering the extraction dynamics.

User avatar
Jeff
Team HB

#32: Post by Jeff »

I found I have to grind significantly coarser to achieve similar flow rates or shot times

lukehk

#33: Post by lukehk »

Do you find this works well with all your grinders? I'm particularly interested in the Bentwood as I do find it harder to hold back the flow in the early stages such as blooms etc. I seem to be getting a lot of channeling at the moment and have planned to use my whatman 5's to try and counter this

GDM528 (original poster)

#34: Post by GDM528 (original poster) »

I've only used one grinder with the filter papers, but I have tried various tricks to manipulate the percentage of fines. I've found the filter papers moderate the impact of changing the grind, giving me more latitude to experiment. That same latitude should extend to different grinders.

If one is thinking about going down the filter paper rabbit-hole, consider adding the paper midway through the puck. That significantly reduced channeling effects in my shots. Puck resistance/flow rate also stays consistent throughout the entire shot. This is my go-to whenever I absolutely/positively have to pull a good shot. Mid-puck paper is discussed elsewhere in the Tips forum.

An earlier post here identified a 58mm paper that's just the right size for a mid-puck paper insert: Puck paper purveyors?

nameisjoey

#35: Post by nameisjoey »

Jeff wrote:I found I have to grind significantly coarser to achieve similar flow rates or shot times
That's so strange. It's my understanding that this is not the norm and most experience the opposite, myself included. When using a paper filter I have to grind much finer in order to achieve the same shot time and ratio.

GDM528 (original poster)

#36: Post by GDM528 (original poster) »

My theory:

the filter paper typically used for pour-over/drip/french-press has a coarse texture that will capture both fines and larger particles in the mesh of fibers. That constellation of grind size caught in the filter paper will be more permeable than a filter that only captured fines - essential for the gravity-driven pour-over to finish in a reasonable amount of time. That same filter paper in an espresso basket will seem largely transparent to 9bars of pressure and can actually enhance the flow rate by blending the transition from the grind to the perforations in the metal basket - hence grinding finer.

On the other hand, lab-grade paper (that Jeff uses) may have a much narrower constellation of grind that it will capture, such that only fines are enmeshed, resulting in a much denser filter - hence having to grind coarser to reduce the onslaught of fines into the filter paper. Lab-grade paper raises the possibility for engineering extraction pressure/yield, without the stigma associated with using a double-wall pressure basket.

So, paper matters. Yet another rabbit-hole to go down - yay!

Giampiero

#37: Post by Giampiero »

For whom using the bottom paper filter, do you ever watched the basket holes pattern "printed" to the filter once discharged?
I did noticed that i always have a visible pattern only on half of the surface of the filter.
This is a regular behavior with or without pre wetting the paper filter.

GDM528 (original poster)

#38: Post by GDM528 (original poster) replying to Giampiero »

[EDIT: I said something completely different in this first version of this post. I would like to now testify to the power of high-quality photography. Apologies to Giampiero for the error but trying to correct that now.]

Here's the top surface (grind-facing) of the filter paper on the bottom of the puck. During pre-infusion I noted the basket wetted a bit lopsided - and you can see that in the slightly darker upper half of the paper. You can also see the hole pattern in the basket, although it's pretty subtle and gets obscured by the darker patchy areas. The puck wets in a ring through the outermost holes first, but I don't see any sign of that in the paper.

Analyzing the filter paper is interesting, but I don't think I learned anything new beyond just watching the bottom of the basket during pre-infusion. And despite the patchy appearance of the filter paper, it was still a decent shot.


jley08

#39: Post by jley08 »

GDM528 wrote:I've only used one grinder with the filter papers, but I have tried various tricks to manipulate the percentage of fines. I've found the filter papers moderate the impact of changing the grind, giving me more latitude to experiment. That same latitude should extend to different grinders.

If one is thinking about going down the filter paper rabbit-hole, consider adding the paper midway through the puck. That significantly reduced channeling effects in my shots. Puck resistance/flow rate also stays consistent throughout the entire shot. This is my go-to whenever I absolutely/positively have to pull a good shot. Mid-puck paper is discussed elsewhere in the Tips forum.

An earlier post here identified a 58mm paper that's just the right size for a mid-puck paper insert: Puck paper purveyors?

Do you place half of your grounds in first, wet the paper filter, then add the rest of the coffee grounds? Is it just the paper filter in the middle, or do you add a filter on the bottom and top of the puck?

GDM528 (original poster)

#40: Post by GDM528 (original poster) »

jley08 wrote: Do you place half of your grounds in first, wet the paper filter, then add the rest of the coffee grounds? Is it just the paper filter in the middle, or do you add a filter on the bottom and top of the puck?
Brewers concerned about drinking 'essence of filter paper' will rinse all of the papers before using. I don't, but that's just me.

My mid-puck paper goes in dry. The process is already kinda fiddly, so wetting the paper would make it more so. I do wet the bottom paper however, so it will hold in place while I stir and level the first half of the grind.

My stack-up looks like this:
Top Paper (dry)
Half(ish) of grind
Mid Paper (dry)
Half(ish) of grind
Bottom Paper (wet)