coffeeOnTheBrain wrote:Did anyone try to drill some extra holes in the Stagg X?
I did a test today by drilling one hole in the center and have to say it was pretty hard. Well it's steel after all.
I am planning to double the number of holes as a first step and maybe do more later.
After reading Gagne's article and that he mentioned that he would like faster flow always I figured, why not!?!

I do this even though I favor the X over all drippers I own with the V60 coming in second. Better is the enemy of good, I guess.

Gagne uses the metal mesh at the bottom and from what I can gather from his articles I'm not sure if you could get faster drawdowns without bypass happening. He even goes to the trouble of pressing in the fluted edges to get a better seal on the walls and stop bypass. You will have to give an update and tell us if the added holes speed up the drawdown or not.

I would think using Gagne's techniques with the Stagg X on something like the Espro Bloom by adding in a mesh and pressing in the fluted edges of the filter could show you if more holes are better but because of the shape of the brewer, it may be harder to press in all the fluted edges.

I find it funny that all these very refined and niche market brewers that have come out like the Stagg X or Espro Bloom that gets high praise and then guys like Gagne and Rao come in and modify it to make it better. Why isn't there a flat-bottom brewer, with large/many holes and the bottom lined with a mesh filter that comes with non-fluted paper filters that seal to the walls? That seems to be what Gagne and Rao want so why doesn't this kind of brewer exist?

maybe someone could make a silicon insert for the Stagg X that perfectly aligns to the fluted edges of the filters so they seal to the walls and has a mesh bottom. but then if you had that you wouldn't really need the Stagg X and the insert would work by itself.

DamianWarS wrote:... You will have to give an update and tell us if the added holes speed up the drawdown or not.
...

Sure I will update here, I am just a little constrained on time, but I will get to it soonish.

DamianWarS wrote:... You will have to give an update and tell us if the added holes speed up the drawdown or not.
...

I found a few minutes for this today, but I will need a bench drill to drill these holes. In the middle it was possible for me to drill a hole in a precise position, but now I am sliding all over the place. This is postponed indefinitely.

I know this is broadly inspired by Gange's own testings/results on the Stagg X. On one of his recent Patreon blogs he says one of the bigger revelations he has had was the dramatic effect lifting the paper filter from the flat bottom of a brewer had as it frees the pores of the filter so much that the holes of the brewer really don't matter. So based on that it seems to be a bit of a lost cause to focus all this energy on the brewer's holes when all you have to do is put some mesh between the holes and the paper filter to get optimal and even flow. So I wouldn't worry about the holes and just focus on a good mesh at the bottom

While I believe that the mesh can prevent stagnation in the flow I am not sure if it really speeds up the flow at all. I did only the smallest possible sample size in my test but there was no noteworthy enhancement of the speed.
Both cups where made with the same coffee, grind size, pouring technique, etc.
Please read 60@9 as a total of 60ml were reached at 9 seconds.

Without mesh:
60@9
187@57
250@1:24
321@??? I forgot but somewhere between 1:50 and 2:00
drawdown complete@2:29

With mesh
59@8
180@55
250@1:23
321@1:53
drawdown complete@2:28

I did another cup without mesh:
60@9
185@50
248@1:19
320@1:50
2:20

In this last cup the time deviation is much bigger and the flow is faster, maybe due to reaching 320ml a few seconds early, but in the end it shows that the deviation between my pours is much bigger than the effect of the mesh.

This is not to say that I doubt that the mesh is helpful, I would just still hope that more holes make the flow faster anyway

are you pressing in the folds of the pre-pleated filter after prewet to seal the filter to the walls as best as possible? If not then it is likely your flow is based on bypass or water that escapes through the filters and passes along the walls then exits rather than passing through the coffee bed. if it's through bypass then perhaps making the holes bigger will increase the flow, but I suspect it will increase the flow of the bypass not the flow through the coffee bed. This is of course as per the methods of Gagne essentially blocking the flow (or as best as possible) from the walls of the brewer and force the flow to pass through the coffee bed and then out. this is why the mesh is essential because with that much of the filter unavailable for water to pass through the flat bottom of the filter must be as liberated as possible to ensure the flow is unrestricted. After that, the holes are probably big enough to accommodate whatever passes through

DamianWarS wrote:are you pressing in the folds of the pre-pleated filter after prewet to seal the filter to the walls as best as possible? ...

Thank you these are some interesting points!
To answer your question, no I am not. So my "test" is only applicable for everyone who is too lazy to fold the filter like that
My idea was, that the Espro Bloom has faster flow than the Stagg X and that it has more holes

In regards to bypass, I would be very interested in what influences the amount of bypass, e.g.

• does the bypassing water run down on the outside of the filter or does it move in the filter itself

• does the water column above the grounds influence the amount of bypass

• does the speed of draining below the filter influence bypass, e.g. is there more bypass in a bottomless cone

• does the time influence the amount of bypass, e.g. same height of water column above grounds, but different grind size leading to different flow through the grounds

• how does agitation influence bypass

Please excuse me answering my own questions

coffeeOnTheBrain wrote:...
In regards to bypass, I would be very interested in what influences the amount of bypass, e.g.

• does the bypassing water run down on the outside of the filter or does it move in the filter itself

The water almost certainly runs down the outer sides of the filter.

coffeeOnTheBrain wrote:

• does the water column above the grounds influence the amount of bypass

Probably yes, I would guess the higher the column the more water is pushed out of the filter.
A better question would be if the relation is linear.
Another good question might be if bypass is influenced by the height of the water column measured from the bottom of the filter irrespective of the height of the grounds.

coffeeOnTheBrain wrote:

• does the speed of draining below the filter influence bypass, e.g. is there more bypass in a bottomless cone

I would guess that this is pretty hard to answer as there are probably 2 or more factors playing in. If the water accumulates at the bottom of the dripper the bypass per time probably gets less, but the drawdown is slower hence the overall bypass increases. Which effect is weighing in more, I don't know.

coffeeOnTheBrain wrote:

• does the time influence the amount of bypass, e.g. same height of water column above grounds, but different grind size leading to different flow through the grounds

Probably a slower flow through the coffee bed leads to more bypass over time.

coffeeOnTheBrain wrote:

• how does agitation influence bypass

Now that I leave for you to answer

coffeeOnTheBrain wrote:Please excuse me answering my own questions

The water almost certainly runs down the outer sides of the filter.

Probably yes, I would guess the higher the column the more water is pushed out of the filter.
A better question would be if the relation is linear.
Another good question might be if bypass is influenced by the height of the water column measured from the bottom of the filter irrespective of the height of the grounds.

I would guess that this is pretty hard to answer as there are probably 2 or more factors playing in. If the water accumulates at the bottom of the dripper the bypass per time probably gets less, but the drawdown is slower hence the overall bypass increases. Which effect is weighing in more, I don't know.

Probably a slower flow through the coffee bed leads to more bypass over time.

Now that I leave for you to answer

Water takes the path of least resistance so as long as it can flow through the filter at any part of it, then it will flow through the filter provided it's alternative routes have greater resistance. Stuff like agitation may contribute to clogging the filter or changing the resistance of the coffee bed. So im sure it can affect bypass and it may decrease it if the filter pours are clogged up along the walls or if flow through the coffee bed has increased to a point that it's easier for water to pass through.

Stuff like the espro bloom may have lots of bypass or partial bypass from the walls of the brewer by perhaps traveling in and out along the walls. After reading Gange I think it has affected how I approach these brewers and filters and I now consider adding a mesh to any flat bottom.

When you seal the sides you are forcing all (or most) of the water to go through the coffee bed and it may not be desirable results but I think with your testing to know if the mesh does anything if you pressed in the folds and tried one with the mesh and one without you will probably get a faster draw down with the mesh. If you're not pressing in the folds then you will never know how much is bypass and how much is going through the coffee bed to determine if th mesh has a positive effect or not.

I added a mesh to the areopress and treated it as a gravity dripper. (So there is the cap, mesh, then on top of it all the filter) and despite the cap have a lot of holes the mesh made the draw down quicker from 7:00 to 4:30. Because the aeropress has no paper filter along the walls there is zero bypass and all the water must travel through the coffee bed. So the mesh made a difference and I'm a believer.

Using the Aeropress with a mesh as a gravity dripper indeed is very interesting. I did try it and it lead to promising results. Indeed the mesh makes the drawdown faster with the Aeropress.

If the Aeropress is used like that, it can not have bypass. Hence it is much better suited for the no bypass style of brewing than the Stagg X. Nonetheless I am interested in the questions I asked previously, to understand better how I could pour to minimize bypass when not folding in the sides of the paper.