Do you change your routine when using a bottomless portafilter? - Page 2

[HB]

So is there dead space under the bottom of the filter basket between the basket and the portafilter?

The upper lip of the basket makes a watertight seal against the grouphead because it's pressed tightly against its rubber gasket, but the underside of the basket lip does not make a watertight seal against the portafilter. In fact, if it did, the espresso flow would be more likely to go "glug glug" as a vacuum formed behind the outgoing liquid (think of pouring out of two jugs, one with a hole punched in the bottom, one with its bottom intact). Some portafilters have a small notch cutout on the lip to allow air to more easily flow under the lip of the basket (e.g., older Rancilio commercial portafilters).

On a related note, that's why if you're building your own portafilter pressure gauge, the basket must be removed.

[dergitarrist]

I started on a naked portafilter so I can't really say but one of the biggest advantages for me is simply hygiene... nothing gets stuck underneath the basket. Reason enough for me to use one because let's be honest... unless you're pulling a LOT of shots every day it's not going to make much of a difference if there's a spout on there or not.

[cannonfodder]

The type of portafilter should not make a difference. If you use a double, single or no spout the process is the same. Now baskets are a different story. If you change basket styles or sizes you may have to change your dose or distribution method but moving the same basket from portafilter to portafilter should not require any changes.

[mitch236]

The upper lip of the basket makes a watertight seal against the grouphead because it's pressed tightly against its rubber gasket, but the underside of the basket lip does not make a watertight seal against the portafilter. In fact, if it did, the espresso flow would be more likely to go "glug glug" as a vacuum formed behind the outgoing liquid (think of pouring out of two jugs, one with a hole punched in the bottom, one with its bottom intact).

I'm confused by this comment. I haven't read the entire thread so maybe I'm taking it out of context. I thought the water was being fed through the grouphead and therefore doesn't require air to have continuous flow. Think of a garden hose attached to the faucet.

[HB]

Not sure why it's confusing, but I'll try again.

I refer to the liquid exiting the bottom of the basket that eventually makes its way out the portafilter spout. See Randy's cross-section diagram of a standard portafilter; I refer to the space he labeled "3". If that space allowed no air to enter, espresso would flow less readily from "4" due to the formation of a temporary partial vacuum, especially if the exit port were small. Some portafilters have a notch in the rim for this purpose, some have larger exit holes, and some manufacturers do nothing special because they aren't concerned about an occasional "glug glug" in the espresso stream.

[cannonfodder]

You are thinking about the wrong side of the basket. The glug glug would come from the vacuum created as the espresso exited the hole in the bottom of the portafilter, not the water exiting the brew basket into the hollow bowl of the portafilter under the basket.

[mitch236]

I stand corrected. I was thinking about a bottomless PF!

Sorry!!

[innermusic]

I'm hooked on bottomless. I prefer the shots, not to mention being able to see everything. Only thing I'm using my regular PF for is backflushing.

[dkny3939]

As long as your blind basket fits bottomless, there is no reason to use standard PF even for backflushing.