# Flow restrictor



## Nod (Sep 7, 2013)

I realise I am slow and you are all probably already onto this but I just bought a flow restrictor for my bonavita gooseneck kettle. I got it for £3 ish from hasbean. It is awesome and has made a big difference to my pour control when doing Kalita's etc. It has made a significant difference to taste and I have been really surprised so thought I'd give them a big sell for everyone...


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## Jony (Sep 8, 2017)

Good to know.


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## Nod (Sep 7, 2013)

Jony said:


> Good to know.


.. I do pulse pour method for Kalita and it has made a big difference...


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## Jony (Sep 8, 2017)

Never really got my 155 going.


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## Nod (Sep 7, 2013)

I only rarely use 155.. 185 all the way... I still always found it hard to accurately pulse pour... not now


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## Jony (Sep 8, 2017)

mm don't really want a 185 as well,haha


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## Nod (Sep 7, 2013)

I think the 155 with 15gr is good but a 30gr kalita seems more consistent... maybe it is just because I have done 100's of those so better at it.. There is obviously more coffee to work with so maybe that acts as a buffer against errors in technique...


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## the_partisan (Feb 29, 2016)

Yeah it works pretty well with a Kalita because it minimizes agitation and you will have less clogging. With V60 I didn't find it to improve things that much.


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## Jony (Sep 8, 2017)

Ok well I always have two V60 back to back so 185 it is then haha


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## Nod (Sep 7, 2013)

the_partisan said:


> Yeah it works pretty well with a Kalita because it minimizes agitation and you will have less clogging. With V60 I didn't find it to improve things that much.


Ahh that makes sense... I guess avoids channelling as the water comes into contact with the coffee in a much softer way...


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## the_partisan (Feb 29, 2016)

I don't think it's about channeling (I don't think such a thing exists in pour overs) but more about reducing silt in the cup.


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## catpuccino (Jan 5, 2019)

the_partisan said:


> I don't think it's about channeling (I don't think such a thing exists in pour overs) but more about reducing silt in the cup.


 What makes you say that? There are ways to disturb the bed in such a way that a path of least resistance is created (improper pre-wetting/bloom, uneven pour etc). That's what I would always refer to as channelling though the impact might be less so than with what we think about for espresso channelling.

I typically bloom + 2 pours, and certainly if using a very fresh roast and I see gas being released during the first pour it's sometimes possible to see an effect on the draw down where that released disturbed the bed.


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## the_partisan (Feb 29, 2016)

I just don't think it exists or if it exists the effect is wildly exaggerated. I've heard Scott Rao talk about it, but he hasn't really presented any evidence or a way to detect when it happens. Seems more like another one of those theories with no real backing? The coffee I typically brew with doesn't really have a very wild bloom and in generally it's possible to make tasty pour overs without any bloom at all (i.e. using the April method).


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## MWJB (Feb 28, 2012)

catpuccino said:


> What makes you say that? There are ways to disturb the bed in such a way that a path of least resistance is created (improper pre-wetting/bloom, uneven pour etc). That's what I would always refer to as channelling though the impact might be less so than with what we think about for espresso channelling.
> 
> I typically bloom + 2 pours, and certainly if using a very fresh roast and I see gas being released during the first pour it's sometimes possible to see an effect on the draw down where that released disturbed the bed.


 If you had say a Kailta wave, with a coarse grind & you only poured at one edge point, with almost no flow through other parts of the bed, then yes, that would be a problem.

Or, if you had a V60 with such a fine grind that the tip clogged & liquid only percolated through the upper layers, then this would also be a problem.

But both of these situations would be fairly easy to spot, they would also exhibit over-extracted flavours with a low EY. These are very rare occurrences in typical, manual drip brewing.

Drip brews are generally higher extraction, or at least no lower, than any other methods. They taste pretty good too, so can't generally be that channelled.

All the time you are pouring water, whilst you have liquid above the bed, you are disturbing pretty much everything. I guess you could have channels when the bed settles, but I don't see it day to day. There's no compacted puck like in espresso, and even if someone suspects a channelled espresso from what they see, it doesn't matter if the shot still tastes OK. As with drip, catastrophic channelling will have some other clue to its presence.

Off-gassing & draw down times aren't really issues. A quick stir of the bloom should sort this.


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## catpuccino (Jan 5, 2019)

the_partisan said:


> I just don't think it exists or if it exists the effect is wildly exaggerated. I've heard Scott Rao talk about it, but he hasn't really presented any evidence or a way to detect when it happens. Seems more like another one of those theories with no real backing? The coffee I typically brew with doesn't really have a very wild bloom and in generally it's possible to make tasty pour overs without any bloom at all (i.e. using the April method).





MWJB said:


> If you had say a Kailta wave, with a coarse grind & you only poured at one edge point, with almost no flow through other parts of the bed, then yes, that would be a problem?
> 
> Or, if you had a V60 with such a fine grind that the tip clogged & liquid only percolated through the upper layers, then this would also be a problem.
> 
> ...


 Aha OK it's just me picking up on the phrasing then. I agree with all this. How the term channelling is used in relation to pourovers is an interesting thought (e.g. I think it could be instructive when hammering home the importance of how water moves through the bed), but no doubt the impact is overstated. I've never tasted a brew and thought any imbalance is the result of channelling, and it'd generally be wrong to say you could look at a brew bed and "see" channelling. But equally the science behind why dry or unevenly saturated coffee grounds is a bad thing is relatively uncontroversial and channelling at least gives us a way to talk about that as part of uniformity and repeatability.


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## Nod (Sep 7, 2013)

Thanks all... interesting discussion although it does rather make me think my love of the flow restrictor is psychological!!


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## catpuccino (Jan 5, 2019)

Nod said:


> Thanks all... interesting discussion although it does rather make me think my love of the flow restrictor is psychological!!


 For the brew result, maybe. But it's a simple usability thing at the end of the day. When my Brewista is full with all 1.2L, it's harder to control than when it's got 300ml in (it's heavier and oddly balanced). I imagine a flow control restrictor would regulate that somewhat.


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## Nod (Sep 7, 2013)

catpuccino said:


> For the brew result, maybe. But it's a simple usability thing at the end of the day. When my Brewista is full with all 1.2L, it's harder to control than when it's got 300ml in (it's heavier and oddly balanced). I imagine a flow control restrictor would regulate that somewhat.


Yes I agree with that - definitely nicer process to use


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## MWJB (Feb 28, 2012)

Nod said:


> Yes I agree with that - definitely nicer process to use


 Anything that helps you pour gently seems like a good idea.


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## Nod (Sep 7, 2013)

Nod said:


> Yes I agree with that - definitely nicer process to use


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## MWJB (Feb 28, 2012)

catpuccino said:


> But equally the science behind why dry or unevenly saturated coffee grounds is a bad thing is relatively uncontroversial and channelling at least gives us a way to talk about that as part of uniformity and repeatability.


 It's hard to talk about uniformity, because there is no scale, no datum and no way to assess it easily. So if your brews taste good & representative of the coffee, then they must be uniform enough?

Repeatability (given the tiny batch sizes & realistic expectation of repeatability) shouldn't be an issue for any sanity checked manual drip brew method. They won't all taste the same, but a "like a lot" coffee shouldn't be swinging as low as "neither like/dislike", maybe drop into "like moderately".


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