# Espresso extraction slow then fast



## newdent (Feb 20, 2021)

Hey, my shots have been starting off slow but once they are flowing, I'd say they're flowing quite fast. I'll take a video tomorrow. There's no channelling, I very rarely get any jets of water since introducing WDT.

Two new changes are new grinder (downgrade from mazzer SJ to Mignon crono for space reasons) and new beans. Extract coffee roasters have sent the beans out very soon after roasting, only 2 days after! I'm crossing my fingers that the coffee is too fresh (day 6 post-roast now) and its not down to the grinder. I might be making up problems but could envision that if there were lots of fines, it may cause similar symptoms? No research to back this up though...

Appreciate any comments!


----------



## DavecUK (Aug 6, 2013)

@newdent I guess there's a few possibilities....for sure very fresh coffee can be a bit weird, often I have to make it quite fine and a few days later go much coarser. The burrs may need a little running in, although I wouldn't have thought it would create that sort of flow problem. The difficulty is you have changed 2 things, grinder and beans.

What machine are you using and dose...are you doing any pre-infusion etc..


----------



## newdent (Feb 20, 2021)

DavecUK said:


> @newdent I guess there's a few possibilities....for sure very fresh coffee can be a bit weird, often I have to make it quite fine and a few days later go much coarser. The burrs may need a little running in, although I wouldn't have thought it would create that sort of flow problem. The difficulty is you have changed 2 things, grinder and beans.
> 
> What machine are you using and dose...are you doing any pre-infusion etc..


 Thanks Dave. My experience matches yours in that I've had to move from fine to more coarse over the past 6 days. Flow was constant throughout the shot on the first few days, which hopefully means it's a bean issue. This was an interesting read regarding fines; https://www.baristahustle.com/blog/fines-migration/

I'm dosing 18g into an 18g VST basket. Machine is a V2 silvia. No pre-infusion as I've read that pre-infusion has to be done at lower pressure. I'll keep an eye on it, if it's still happening in a week I'll start to worry! It's kinda frustrating that extract have sent out coffee before it's useable, they seem to do this a lot! I do like their coffee though so have to put up with it..


----------



## 29244 (Feb 8, 2021)

Video would definitely help.


----------



## DavecUK (Aug 6, 2013)

newdent said:


> ! It's kinda frustrating that extract have sent out coffee before it's useable, they seem to do this a lot! I do like their coffee though so have to put up with it..


 I think it's fine for them to send stuff out as fresh as possible, so the customer can decide when. It might also be that some people want to hang onto it for a few weeks before getting to it if they have other coffee on the go. I usually can't wait with my own coffee and will often open it after 5 days, because I have run out...but I prefer to way at least 7-10 days. The stuff I'm drinking at the moment was roasted almost4.5 weeks ago.


----------



## newdent (Feb 20, 2021)

Yeh, appreciate that roast date is going to be luck of the draw. If I'd had some coffee left, would have definitely waited.

Wow that's old coffee, has it been in the freezer?!


----------



## DavecUK (Aug 6, 2013)

newdent said:


> Yeh, appreciate that roast date is going to be luck of the draw. If I'd had some coffee left, would have definitely waited.
> 
> Wow that's old coffee, has it been in the freezer?!


 No, I don't pack in valve bags, I use a completely sealed food grade mylar bag. Many of my extractions you see on video are of 2 and 3 month old coffee...they look and taste as fresh as when packed. If I used a valve bag, yes, coffee has to be used within 6 or so weeks. I don't even put these bags in the fridge, although during the heat of summer, I will often store them in the fridge.

I talked about packaging a few times, or tried to in the past, explained what I was doing and why....along with evidence.


----------



## Mrboots2u (May 10, 2013)

https://www.coffeeforums.co.uk/topic/55351-resting-coffee-why-and-how-long/?do=embed

I see forums discuss the abilities of a gridner to produce more or less fines , that seem to be being measured by the eye, or it feeling.

don't get stuck in too much abstract concepts and measurements that you can't measure, of course you can surmise and guess but it isn't always

helpful as to what do next. All grinders produce fines .

rest the coffee more , don't stress over it speeding up unless there is a taste defect. At the moment that taste defect could be done to overtly fresh coffee .

If you are worried about the speeding up of extraction being a result of channeling are you using a naked pf. Most shots will speed up as the puck gives up coffee , this in itself isn't a problem .


----------



## newdent (Feb 20, 2021)

To be fair, I think experiments with sifting have been done to prove slightly more fines with the 50mm mignon grinder.

That being said, the coffee doesn't taste bad, even with the change of flow rate. My intuition is telling me there's something off with it as it's two extremes. First dripping through and then flowing quite fast. I'll have another coffee in a bit and get a video.


----------



## Mrboots2u (May 10, 2013)

newdent said:


> To be fair, I think experiments with sifting have been done to prove slightly more fines with the 50mm mignon grinder.
> 
> That being said, the coffee doesn't taste bad, even with the change of flow rate. My intuition is telling me there's something off with it as it's two extremes. First dripping through and then flowing quite fast. I'll have another coffee in a bit and get a video.


 Are you using a naked pf . If not a video probably won't show enough detail to say.
Most basic sieve experiments won't tell the the level of fines that a Grinder is working at .

im. It saying that there isn't a difference between the grinders or your shot quality , but merely attributing it to something you aren't measuring an dcant change isn't always helpful.


----------



## Mrboots2u (May 10, 2013)

Shots speed up under a contrast pressure , channeling can cause this , easiest way is diagnose is through a naked pf . Otherwise you will get people guessing at reasons such as below along with associated suggestions .

too hiGh a dose - check basket tolerance and coin test

too low a dose - check basket tolerance

uneven distribution -rest

A result of single dosing - dont single dose

ill fitting tamper - new gear

too fine a grind - coarsen grind , perhaps updose a little


----------



## Rob1 (Apr 9, 2015)

The chances of there being something wrong with the beans are slim to none. You may have something that isn't suitable for use as espresso though. The majority of roasters in my experience send coffee out very soon after roasting, the clue is "roasted to order" somewhere on their website. I've never received a coffee that was ready to drink, the oldest I've had delivered was 7 days post-roast and that was a one off. With some brew methods you can use it straight away even if it will still benefit from resting. All shots speed up through extraction, some beans will speed up more than others, some will look awful coming out of a bottomless filter.


----------



## ajohn (Sep 23, 2017)

If it's a new grinder several kg of beans often lessens fines but that usually results in the need to set finer. It's not something I have found all that noticeable on flats taste wise. Niche different and not for long  and a Sage grinder with a loose central burr. Beans may vary that a lot - eg light roasts. Some people put loads through SSP HU burrs and I mean loads before making drinks with them.

Flat burrs with hopper on may go in the other direction for a while. My nick name might be have used too many makes of grinders for a while. I put it down to grinds compacting in the grinds chamber and on the way out. Some people have noticed this having switched from weighing in back to hopper on and finding they need to use a noticeably coarser setting. I have. So following a clean out expect this to happen. Another problem I have noticed is the number of shots pulled. In the early days that may have been 10 a day. Now it's 2 or 3 usually and things take a lot longer to show trends.  Wife prefers her pods and son can't be bothered.

Bean age - pass I don't think it's possible to be categoric about it. Beans vary too much. Personally I found that by mostly using a particular bean and learning how to handle it is the best way. Then if I try a new bean I can take my time drinking it and see what happens. The roaster I use most often roasts several times a week. One bean I have off them does need to be fresh and always is. I have bought packs in the past of a roaster in a quantity a cafe type place might use - the use by time was surprisingly long.


----------



## newdent (Feb 20, 2021)

Thanks for the replies everyone. Took a video and looks like the tiny adjustment I made to the grind setting after my last coffee has tipped it the other way and running fast the entire time now. I obviously don't have a lot of adjustment to play with, must be right on the edge of the grind setting I need for my 1:1 ristretto, think this one was about 20 seconds.

Guess that means it's a grind issue...

View attachment Extraction1.mp4


----------

