# Dwell time/extraction time



## James87 (Sep 8, 2016)

Hi, I'm after a bit of advice with dwell time to extraction time ratio (If you could call it that).

I'm using a Gaggia classic and I've currently got the grind dialled in to a 1:2 brew ratio with 18g in and 36 out (further question: do you stop timing at 36 or when you turn the machine off a couple of g's before to allow for added drip weight?).

At the moment, the dwell time is about 7 to 8 seconds, which to my knowledge is at the upper end, but the shot then completes in a total of about 25 seconds, which I understand to be at the lower end of desired range. Basically what I've noticed is that the initial dwell time is quite long in comparison to the overall shot time. For me to grind finer and have a shot that completes this brew ratio in the upper end of the range (ie 30 seconds) the dwell time would be to the point of almost choking or creating an undrinkable syrup.

My question then is whether this is not a problem of grind setting, but rather technique. Could it be that I'm tamping too hard? Would I be better grinding finer and tamping lighter perhaps to get a longer brew time but with a shorter dwell time? The long dwell time is (I think) causing some bitterness to be extracted, but then the overall low shot time resulting in some sourness all in the same cup - please correct me if I'm wrong. It seems to me that the shot has a very slow start but then accelerates through the mid-stage to finish in a quicker time than expected.

Any tips or questions welcome.

Thanks,

James.


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## Mrboots2u (May 10, 2013)

Dont judge a shot by time , judge it by taste , Stop the shot when you hot your desired brew ratio , not a time . Tasty can happen form anywhere 20-50 seconds .

Keep your tamp consistent , til the coffee wont compact no more isnt a bad way to judge .

Shots accelerate as they extract , dont worry about this . Don't worry about blonde not blonde . Or mouse tails.

The visuals that will help will come from a naked portafilter .

Use your taste buds to guide your adjustment .If you want the shot sweeter try grinding finer until its obvious you have gone too far via taste .

If you are struggling to get the taste imbalance add a little dash of water to see if that helps .

Also 1:2 isnt given as a tasty for everyone , it's just a starting point not a absolute

https://baristahustle.com/the-espresso-compass/


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## James87 (Sep 8, 2016)

Thanks, I think I'm possibly over thinking it. I think I must be towards the lower left side of that compass so have a very small "sweet spot". The only way to increase this would be to improve extraction. I'd hope my extraction is pretty even, I dose into a separate pot and then break up clumps before pouring evenly into the portafilter. I'm waiting for a vst basket and hoping this will improve the shot compared with the standard gaggia double which has that curved/angled base to it. Think I'll wait until my setup reaches its final form before starting to mess about too much with dose/yield and grind because it'll most likely all change and need dialling in again anyway.


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## Mrboots2u (May 10, 2013)

You can improve extraction by either grinding finer and keeping the same brew ratio ( time of the shot will change )

OR

Change your brew ratio to a longer one - the shot may be sweeter much weaker ...


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## James87 (Sep 8, 2016)

I was worried about extending the brew ratio if a 2:1 was already showing some bitterness. See I've even fallen at the first hurdle really I can't even decide on a dose weight as there's so many different opinions out there on the gaggia basket from between 14 and 21g. Be much easier when the vst basket arrives and I know the weight it's designed for.


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## Mrboots2u (May 10, 2013)

Stick to a basket and a dose relevant to that basket .

Stock gaggia should be fine at 16g . 21 g will be the triple basket

Extraction and taste aren' linear so you may find you can push through to sweetness by either extending the ratio or grinding finer .


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