Left side bias on bottomless PF

[Blaine]

I've been watching my shots recently on my bottomless PF and to varying extents they always seem to start on the left third then the funnel migrates to the right as I get blonding on the left.

I've tried removing and cleaning the brass dispersion screens.

I also have used a thin wire to ensure even distribution of the grounds before tamping.

Coffee is Counter Culture Apollo, grinder is Macap.

Any ideas on where I should start to improve the even extraction of my shots?

Thanks in advance.

- Blaine

[Endo]

Most of the time this has to do with channeling. Still, there is another possible reason, and the fix is rather easy:

If the bottom of your basket is concave (highest point at the center), the shots will always drip down to the side. Even if it perfectly flat, the slightest tilt of the machine will cause it to go to one side. But if you take out the basket and tap the center slightly with a soft ball hammer (be gentle), it will form a slight convex shape with the lowest point at the center. Any drips then tend to collect there. It's almost cheating.

I always wanted to make an extreme "V" basket (with 45 deg angle) along with a slight "V" shaped tamper. (Kinda like a Hario V60 pourover). This way it would have the same basket flow area as a 58mm machine, or maybe more even. You could updose as well. Although you would need to use a stand for tamping.

[Blaine]

Endo - here is a short video. Could there be anything inside the head which could cause this? It can be worse at times.


http://gallery.me.com/wbstine#100024/Left%20bias

[bgour]

Do you tamp with the basket in the portafilter? My guess is that your tamp is biasing to one side.

I often get the same thing, despite consciously trying to apply even pressure. Some nutation helps.

Good luck!

[jpt]

Blaine, have you solved your problem?

I have got my Vivaldi for a couple of weeks now, and all the time there has been the problem that the pours seem to start from the left-front side of the filter. Today I had to stay home with my sick kids, so I thought about trying to solve that problem out. I run out of fresh coffee and had to use some stale beans; the pours got even more uneven.

I poured 20+ shots with varying different things, I even tried tamping so that there was more coffee on that problematic side. Still, more or less every time the pour started from the left-front side. Then at some point I ground the coffee into a jar, closed the lid and gave it a good shake in order to get rid of the clumps (my current grinder is a clump-master; Nuova Simonelli Grinta). Voila, even pour! Some more testing and then I realized that there are two different types of grinds coming from the grinder: loose grinds that tend to drop closer to the grinder and clumps that get thrown a bit further. I hold the portafilter with my left hand so the loose grinds tend to end up in the left-front part of the filter (even though I move the filter underneath the spout). The loose grinds are probably somewhat coarser than the clumps, at least that would explain the uneven pour. So I guess that until I get enough money to upgrade the grinder I'll be using the jar.

[GDK]

Great troubleshooting! I guess a quick stir with a toothpick once coffee is in the basked could help quite a bit. This is part of a technique many (including Endo I believe) are using.

[Endo]

First thing to check is the level on your machine. Put a bubble level on the bottom of you naked portafilter and check if it's level. If not, put shims under the legs to level it. As a quick sanity check (to see if flatness is the source of the issue or not) just lift the side of the machine where the stream normally goes and see if that fixes things.

That said, if you discover the problem is in the basket (i.e. technique), I can say I've had my most centered pours when I use WDT (although I personally don't use it since I don't think it's worth the added prep time).

Actually, if you want to cheat a little....the gas from VERY fresh coffee (less than 10 days from roast) produces a MASSIVELY wide cone and will hide any imperfections making for beautiful YouTube videos.

While the bottomless P/F is useful for resolving problems in technique (channeling, jets, etc), one can easily overdo it. I think a little "wandering" of the main stream does not significantly impact taste. Too much examination of the pour "streamology" is akin to too much examination of the spent puck "puckology".

[jpt]

I guess a quick stir with a toothpick once coffee is in the basked could help quite a bit. This is part of a technique many (including Endo I believe) are using.

I did use a fork for stirring at some point today. That didn't help. Actually if you think of it, a toothpick or a fork doesn't move the grinds very much, they just break the structure. That doesn't help in my case. So at this point I prefer my grinds shaken not stirred .

[jpt]

First thing to check is the level on your machine.

That might solve the problem of the cone not being centered. I don't see how that would solve the early blonding of the other side.

While the bottomless P/F is useful for resolving problems in technique (channeling, jets, etc), one can easily overdo it. I think a little "wandering" of the main stream does not significantly impact taste. Too much examination of the pour "streamology" is akin to too much examination of the spent puck "puckology".

However, if the streamology is able to solve systematic "errors" as in my case, then it is worthwhile. I share your belief that small random wandering of the stream should be ok.

[oton]

First thing to check is the level on your machine.

That might solve the problem of the cone not being centered. I don't see how that would solve the early blonding of the other side.

If more water runs on one side, early blonding you'll get on that side.

[GDK]

So at this point I prefer my grinds shaken not stirred .

[Endo]

First thing to check is the level on your machine.

That might solve the problem of the cone not being centered. I don't see how that would solve the early blonding of the other side.

You are absolutely right. One side and early blonding is channeling.

Like I've said before.....nutation seems to solve a LOT of the channeling problems on the Vivaldi.