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View Full Version : Choking. What to do when choking occurs



Jumbo Ratty
03-03-15, 12:49
So, Ive managed to choke my Gaggia Classic.
It was either the grind was too fine, the tamp was too hard or a combination of the two. Please advise if there is another reason for this as those are the only variables I can come up with. This is by no means a frequent occurrence, but it has happened a few times as I get used to grind / tamping

What I want to know is whether it can cause harm to the machine. If so, what harm will it do? I presume the pump may suffer ?

Should you continue letting the machine chug away for the next 20 seconds with nothing coming out in the hope it pulls through ? Sometimes it does finally produce a shot with it dripping out over the next 75 seconds or so after the initial 20 seconds of nothing.

Or should you abort the shot as soon as you realise it's choked ?

NJD1977
03-03-15, 12:53
It's caused when your grind is too fine usually, but it can also be overtamping.

There's no problem with it in terms of damaging the machine, because the OPV will just vent off the water anyway back into the reservoir. That said, there's not much point in watching a choking machine choke for a long time. Generally if it's not even started dripping by 12-15 seconds, it's probably not going to be a good shot and you could mission abort.

You can normally tell within the first few seconds of the tone of the pump whether the machine is/will be choked or not because you can sort of hear it passing through the puck (or not if it's choked).

Eyedee
03-03-15, 01:00
It cannot do the pump much good straining to push water through a choked shot, it's not going to add to it's life cycle and I would surmise that it will actually shorten it's life.
Just stop the shot, keep the tamp constant and vary the grind accordingly.

It's important just to alter one of the variables at a time but the tamp is the one thing that can remain constant, the grind and the dose make a massive difference.

Ian

Mr O
03-03-15, 01:26
I had this happen when I went too fine / tamped too hard. But when I realised it wasn't a goer I aborted. I don't thing the espresso it makes would be very tasty if it takes 60 seconds to get a shot. This way you know there is no damage to the machine, just a handful of beans wasted...

StuartS
03-03-15, 01:49
When the coffee puck offers too much resistance, all the flow goes through the OPV and protects the machine from damage, however I don't think you want to run the machine "choked" for too long or too often.

I found my classic a bit prone to choking when I was trying to get to a 1:2 brew ratio in 25-30s. As I ground finer to slow the shot down, it would suddenly choke. There seemed to be a step change in the OPV behaviour.

I have had no problems since reducing the OPV setting to 10 bar. The machine will happily go below 1:2 if required and it seems much more responsive to changes grind. I am sure my OPV was sticking and the adjustment has freed it up.

MrShades
03-03-15, 01:57
Tamping too hard won't make too much difference to it choking or not.

The biggest factors are:

1. Grind - too fine and it'll choke, so loosen the grind a little
2. Quantity of ground coffee - too much and it'll choke, so reduce the amount of coffee in the basket.

Obviously if you're aiming to extract a reasonable amount and you're at the bottom end of what your double basket is designed for then you only have grind to play with. If you're pushing 19g into a double basket, then you could EITHER reduce the amount (down to 18g for example) OR loosen the grind a little. Not usually a good idea to do both at the same time!

Tamp will have SOME effect, but as long as you have a compressed puck and smooth/polished top to it, not much.

KkAaNnEe
03-03-15, 03:20
If it has only happened a couple times then I would agree with MrShades above that you may have put too much coffee in, this in my experience has been the most obvious, so long as you are keeping the grind the same. Tamp pressure is a possibility but less likely as there seems to be a bit of a tamping limit unless you are particularly strong.

Rhys
03-03-15, 03:26
Choking will produce the same effect as backflushing yes? Classics can be backflushed so can't see the harm as long as it's aborted when you realise nothing is coming out?

Mrboots2u
03-03-15, 03:31
Choking = too fine a grind ( and too inconsistent ) or too much coffee or both - are you weighing your dose or using scoops btw..
How much coffee was in the portafilter...

coffeechap
03-03-15, 03:38
Choking = too fine a grind

no boots choking is what you do in the latte art comps

Mrboots2u
03-03-15, 03:41
no boots choking is what you do in the latte art comps

And so it begins

Jumbo Ratty
03-03-15, 03:55
Using scoops. I have weighed my scoops previously over a trail period and they where quite consistently the same weight withing reason, no more than + or - 1 gram over 32 grams.

I havent choked my machine using pre ground coffee even if I tamped as hard as I dared. So I imagine its too fine a grind, or inconsistent grind particle size due to my inferior grinder. But I thought that was the case.

My main concern is \ was that I could potentially damage the pump or some other internal part if I didn't abort the choked shot.

Mrboots2u
03-03-15, 04:00
Do how much are you dosing into the PF ? I'm confused is it 16 g or 32 g ?
Up to you , my advise is to ditch the scoop , it's a inconsistent way to dose coffee , if you are happy with what you are making then stick to your preferred method ...
You won't choke a machine with pre ground , it's stale and not to a correct grind for your dose and machine and not it s creating the pressure in the pf , unless you massively over doing it
When you change coffee and or grind tscoop will have a different weigh of coffee In it. There is a reason you a trial blazing by using a scoop , coz on the whole it's not a great way to effectively control dose

Jumbo Ratty
03-03-15, 04:08
16 grams per PF, I always make coffee for two people, hence the 32 grams stated which is 4 scoops.

Mrboots2u
03-03-15, 04:11
16 grams per PF, I always make coffee for two people, hence the 32 grams stated which is 4 scoops.

Are you grinding 32 g in one go , or 16 make coffee then another 16 and make coffee . Again grinding 32 g and splitting isn't going to help you achieve a consist consistent mix of particle sizes ...

Mrboots2u
03-03-15, 04:13
Or are you using a scoop to measure whole beans into the grinder ?

froggystyle
03-03-15, 04:16
Scales, scales, scales, scales.....

Weigh, weigh, weigh, weigh.....


Catch my drift?

MWJB
03-03-15, 04:22
16 grams per PF, I always make coffee for two people, hence the 32 grams stated which is 4 scoops.

If you have scales to weigh the scoops why not just weigh the doses?

+/-1g per 32g may/may not mean 0.5g per 16g. E.g. if your scales are 1g resolution you might find they are actually +/-2 or 3g accuracy.

It would be best to weigh each dose & shot on at least 0.1g resolution scales.

Jumbo Ratty
03-03-15, 04:25
32 grams of whole beans in one go in my Krups 75 in 20 seconds, upped from 17.5 seconds as grind not fine enough I thought. Yes I appreciate its a contender for the worlds worst grinder but it's something I have had for a while that was given to me as a gift and is what I have to work with :)

Mrboots2u
03-03-15, 04:30
It's probably is your grind and grinder but adjusting the grind and having a variable dose of coffee being used isn't helping ( via scoop amount then unknown amount in the PF , what's being retained in the grinder Are you actually splitting it equally ...)
I get you want no faff and excellent coffee but I would suggest some consistency in your approach to help ...
You will get a version of the same advise of a few people, on here , primarily because they have found it to help in the long run....
Altho not the only way to make a drink , it does allow a common language to help make adjustments and give advise .
It is entirely up to you if you want to try it though

MWJB
03-03-15, 04:36
32 grams of whole beans in one go in my Krups 75 in 20 seconds, upped from 17.5 seconds as grind not fine enough I thought. Yes I appreciate its a contender for the worlds worst grinder but it's something I have had for a while that was given to me as a gift and is what I have to work with :)

Well the grinder you have is the grinder you have, whether using that or if upgrading in the future, it's still best to weigh what goes in the PF rather than what goes in the grinder, some grinds will be trapped in the grinder and the water & pump won't take that retention into consideration.

MartinB
03-03-15, 05:13
The best thing you can do is spend a fiver and get some scales.

Jumbo Ratty
03-03-15, 05:22
What I want to know is whether it can cause harm to the machine. If so, what harm will it do? I presume the pump may suffer ?

Should you continue letting the machine chug away for the next 20 seconds with nothing coming out in the hope it pulls through ? Sometimes it does finally produce a shot with it dripping out over the next 75 seconds or so after the initial 20 seconds of nothing.

Or should you abort the shot as soon as you realise it's choked ?

I have scales, Im just not that anal as to want to use my scales everytime I make coffee.
My question is what harm will choking do to the choked machine and should the choked shot be aborted.

coffeechap
03-03-15, 05:24
how old is the gaggia

Jumbo Ratty
03-03-15, 05:26
brand new 2015 SS boiler version

MWJB
03-03-15, 05:30
I have scales, Im just not that anal as to want to use my scales everytime I make coffee.
My question is what harm will choking do to the choked machine and should the choked shot be aborted.

It's not anal, it's just adhering to the universal laws of percolation brewing. If you get a decent level of consistency, use same/similar beans, you won't be making massive adjustments & choking will become less of an occurrence.

What does it matter if your pump lasts a lifetime, but 1/3 of your coffee goes down the sink, or in the bin in soggy, non extracted, choked pucks?

coffeechap
03-03-15, 05:31
so no solenoid then to release the pressure. stop the shot and carefully remove the portafilter, but remember there will still be pressure in the basket.

NJD1977
03-03-15, 05:33
My question is what harm will choking do to the choked machine and should the choked shot be aborted.

Choking the machine won't harm it, but running the pump on a choked machine for a long period of time isn't a great idea.

Yes generally - just abort if your shot hasn't started pouring before 12-15 seconds.

froggystyle
03-03-15, 05:34
I used to think exactly the same, who wants to use scales... Its now part of my routine and i don't notice.

What does it mean, it means you get consistency in your shots, if you dosing the same, outputting the same in the same time, then your getting near as dammit the same drink.

Don't do it, even more so with a cheap grinder that is gonna spit out all sorts of particle sizes, your getting be binning shots, or drinking bad shots.

Mrboots2u
03-03-15, 05:55
I have scales, Im just not that anal as to want to use my scales everytime I make coffee.
My question is what harm will choking do to the choked machine and should the choked shot be aborted.

And my answer was trying to help you not choke that machine again ...( by potential overdosing now or in the future )
Sometimes debates like this can come across as combative on a forum , i dont mean to be ...its really not my intention ....
You see the validity of measuring ( via a scoop ) , scales are just in my opinion a more accurate way of doing this....
What would eb the appropriate amount of times to use scales to make coffee before it became anal ? 1 in 10 3 in 10 ?
Is measuring the amount in a scoop anymore anal that just using scale ??? Who knows , ill make an anal scale and graph so i can plot the answer...
Anality would probably go on the Y axis though
If you are happy with your coffee and the way it taste's then , use the method you prefer , really , its no skin of my nose . I just want you to enjoy the drink you make....
If though you ask advise re , adjusting the way a drink tastes then its worth bearing in mind that the first response that you will get, is probably along the lines of what is your dose v coffee out ( by weight ) . If you dont know that , then advice will be hard to give ...and you will be asked if you can use scales..
Weighing by scales isn't the only way to make coffee, plenty of people on here make excellent coffee without them , and i know i in particular i can sound like a broken record and or the leader to the worst/dullest cult ever when i post on here about using scales ....it is though just friendly advice in the end , take it or don't I'm not offended ...but i and others will struggle to help, if you post a question on how to adjust taste , if you can't relay the info in some kind of common language ..( weight )
Have fun

Jumbo Ratty
03-03-15, 06:00
What does it matter if your pump lasts a lifetime, but 1/3 of your coffee goes down the sink, or in the bin in soggy, non extracted, choked pucks?

A slight exaggeration seeing as I make approx 6 cups a day and have only fully choked it once and partially choked it 3 to 4 times since the start of this year.
I believe you have to choke your machine at some stage in the learning curve to find your limits.

coffeechap
03-03-15, 06:04
The problem with the latest variant of the gaggia is the lack of the solenoid as this does allow to stop a shot and remove the portafilter immediately without the risk of coffee spraying everywhere, such a shame as they were the go to machine for entry level espresso, not really sure of te build quality now.

Eyedee
03-03-15, 06:42
Forgive my ignorance here it's just curiosity but if there is no solenoid how does the pressure in the PF normally get released without a major spraying experience.

Ian

coffeechap
03-03-15, 06:53
It will dissipate but not instantly so you have to let it release through the puck, which is tough if the Maxine has choked

Mrboots2u
03-03-15, 06:53
It will dissipate but not instantly so you have to let it release through the puck, which is tough if the Maxine has choked
Who is Maxine ?

coffeechap
03-03-15, 06:55
My pet name for the new classic

Eyedee
03-03-15, 06:55
I resisted making that comment

Ian

urbanbumpkin
03-03-15, 07:17
Who is Maxine ?

Quite open minded by the sound of things.

coffeechap
03-03-15, 07:50
Me and Maxine have an understanding

The Systemic Kid
03-03-15, 08:23
Or is that an arrangement?

coffeechap
03-03-15, 08:35
look she understands. I think

The Systemic Kid
03-03-15, 08:43
Are you sure?

TomBurtonArt
03-03-15, 08:55
Always have a friend on speed dial.
http://tapatalk.imageshack.com/v2/15/03/03/c147caa9165d661b07c8853afc76d37a.jpg





Apologies for the sick, sick nature of my joke.

urbanbumpkin
03-03-15, 09:21
Are you sure?

I don't think he cares if she does. Hope you've agreed a safe word.

MartinB
04-03-15, 12:26
In all honesty, I can't see the machine being damaged at all by choking. The machine has an OPV which should work and route the water back to the reservoir when the water doesn't make it's way through the coffee.

You don't weigh your coffee each time? Sorry if this sounds patronising however, you're looking for answers yet you don't actually know how much coffee you're putting in your machine... You may be choking the machine because you're using too much coffee. It's all about controlling the variables - I suggest you do so and report back.