What's the key criteria for stopping espresso extraction?

[jovial]

I'm confused as to which factor is the most important factor in stopping the espresso extraction,
or in other words which is a proper indication of perfect coffee brewing.

I've read that a good espresso extraction (for one filter cup) relates to the following properties:

1. it is an ounce of espresso (in quantity)
2. it takes 12 to 15 seconds to extract (in time)
3. and has (perferably three-colored) crema on top, that loosens in texture at the end of extraction (in quality)


I have to admit, my espresso shots don't meet _all_ the above criteria at the end....
for example, i have noticed that I can get more crema if I extract more than one ounce.

so, if i'm not getting the perfect shots yet, which one of the above factors should I prioritize and try to maintain while practicing and trying to get the other factors right?

[Zendel]

Your extraction time should be in the neighborhood of 25-30 seconds. I think the key to stopping the extraction is the color of the flow.

[HB]

Jim explains this well in Working the Shot of The Home Barista's Guide to Espresso (emphasis added):

The first aspect of working the shot is to make sure the extraction is correct by ending the shot at the same color every time. The exact color depends on blend and machine, but it is always a light tan described by experienced baristas as blonde. If the stream is still well filled with crema, it is not yet blonde. If the stream entering the cup discolors the crema into a light tan color, it's gotten lighter than blonde. Typically the right point is around the time when the stream starts changing from foam to liquid.

He goes on to explain Al's Rule and the Rule of Thirds. It's a must-read guide in my opinion. Another great way to gather opinions on the "right time" is with a video, e.g., Videos of espresso extractions. I don't make all that many videos, especially since the house is rarely quiet enough for them. Below is one I made for the Buyer's Guide to the Gaggia Achille:

Also on youtube


Not the best shot I've ever pulled, but a good one. The transition point from foam to liquid was around the 60 second mark of the video.

[jovial]

Your extraction time should be in the neighborhood of 25-30 seconds. I think the key to stopping the extraction is the color of the flow.

Zendel and HB, thank you for your replies.
I have seen many espresso extraction videos, but sadly not many with a pressurized portafilter (which is what i'm stuck with).

have a look at this video please....


the espresso extraction time in this video is 12 seconds from the moment that the machine is turned on to the end of extraction.....
it is in the region of 8 seconds if you start counting from the time that the espresso starts appearing.
(agreed, the guy doesn't tamp at all (which deserves a question on its own, considering his expertize), and some of that crema is fake... but look at the espresso... it looks good)
would you call this guys espresso shot under-extracted ??

I've experimented with various grinds (too fine to even get stuck in my portafilter holes) and tamping pressure (have tamped so much, was almost thinking my portafilter is bent at the bottom yesterday!)
and i've never been able to stretch the extraction time into this 25 to 30 seconds region.

it's as if my machine is just programmed to give me a fixed water flow rate.... and the more i try to lower the flow rate, the louder it gets, and the worse the espresso turns out to be.

[another_jim]

A pressurized portafilter removes almost all the control over extraction parameters. Tamping and grind variations alone will not help -- since most of the pressure drop is happening at the restrictor orifice. This means the fines won't migrate and a regular puck won't form. In general, these machines produce a flow color at the start of the shot that is lighter than where I end my shot on a regular machine. This doesn't necessarily mean the coffee is wimpy, it means the optics of pressurized PF flow is different from that of unpressurized PFs. My guess is that the bubbles in the flow are much larger, since restrictor crema always looks sudsy.

The trick to a good extraction is creating a good puck and maintaining it during the shot, nothing more, nothing less. Since you don't get any help from the machine, you'll need to do this for yourself before you start the shot. While I'm not at all sure how to go about doing this, I do have some suggestions on things to try, based on tall-tale like stories of Paul Bassett's prowess with these machines and the physics of percolation:

1. Overfill the basket so that the PF is hard to insert into the group -- this will keep the puck solid rather than turning it into a slurry

2. Tappity tap the heck out of the basket or PF after you've filled it with grounds, but before you tamp. The idea is that the vibration will get the fines to the bottom of the puck, where they belong -- this is usually done by the first five seconds of flow, but it probably doesn't happen in a pressurized basket.

3. Grind fine enough so the above two techniques have the machine dancing on the edge of self-destruction when pulling the shots. According to the Bassett stories, this is quite essential. In any case, the sooner this machine self-destructs, the sooner you can get a proper one.

[HB]

...and some of that crema is fake... but look at the espresso... it looks good) would you call this guys espresso shot under-extracted ??

Jim gave you some excellent advice. To be certain we're on the same page though, that shot doesn't look the least bit appealing to me. Pale blond and uniform "crema" produced in less than 15 seconds. All the espressos I've tasted extracted at that rate were weak, low in body, and sour (or bitter/sour due to combined temperature/extraction issues).

Contrast the espresso you see in the video with this one from Illy's The Complexity of Coffee:

Hazelnut coloring with reddish reflections

Or this one from John Weiss' WDT:

Gorgeous striping and excellent coloration

Now that looks good.

[jovial]

Jim, I think you're quite right.

Opinions on the subject of pressurized portafilters vary alot.

On the positive side, we have opinions like this:
"Pressurized Portafilter. This type of portafilter creates the pressure for you. That's right, it is not dependent on your tamping and grinding correctly. They have a device that will only allow the water to pass when the appropriate pressure has been developed. These systems were created to make it easier to obtain good coffee. Espresso is known for its intense flavor, but many users came to think that it was nothing but bitter. If they knew to make some simple adjustments they would have saved their palate. To bypass this experience the pressurized portafilters were developed. Some use a valve and others use a special filter basket. The result is the same for both, proper pressure development and excellent espresso." (source http://www.wholelattelove.com/art...g_portafilters.cfm)

On the negative side, we have opinions, some as harsh as this:
"When the espresso goes through that valve, any true crema is destroyed." (source http://www.espressomacchina.ca/before/bigcaveat.html)

And, my opinion is increasingly shifting towards the negative side now.......

There's no need for self-destruction... as soon as I get another negative feedback on this pressurized portafilter business,
i'll make the following picture a true reality.

[jovial]

oh, looks like HB posted a message while I was writing mine.

Thanks HB, I think i'm gonna de-pressurize my portafilter or get my hands on an Elektra filter basket.
This pressurized portafilter business, I think is now out of question.

[jesawdy]

In any case, the sooner this machine self-destructs, the sooner you can get a proper one.

Ha! Funny....

But seriously, on another note, if you have that same machine you can do yourself some help by acquiring a replacement portafilter for it. You can get a non-pressurized version. If you are in the US, try Saeco USA direct (http://www.saeco-usa.com/), or calling one of their authorized repair centers or maybe even espressoparts.com. The non-pressurized version is a bit of an eyesore compared to the more attractive looking one it comes with. I have seen used ones on coffeegeek.com (and others looking for them). (A friend has gotten good service from Coffee Boss in CORNELIUS, NC Tel: 704-987-3310 for a superauto part).

A 25-30 second extraction is quite doable with the replacement portafilter. Fresh beans of course, and the grinder (always the grinder) needs to be up to the task. The one in the video CAN do it, but you'll have maybe one or two usable espresso settings, and the gods will need to be one your side. I think the basket is 52 or 53mm, so a tamper would be helpful (or something approximating one at least).

Let us know more about your setup, machine, grinder, beans, and see about acquiring a new portafilter.

[DC]

Contrast the espresso you see in the video with this one from Illy's The Complexity of Coffee:

Or this one from John Weiss' WDT:

Wow... I've never been served/been able to make espresso that has that deep a red-brown colour to the flow or with crema even close to being the colour of that one from the illy pic. Looks like hot chocolate!

DC

[k7qz]

Wow... I've never been served/been able to make espresso that has that deep a red-brown colour to the flow or with crema even close to being the colour of that one from the illy pic. Looks like hot chocolate!

DC

Spend time learning from the good people and the resources on this site and you will!

[Psyd]

Spend time learning from the good people and the resources on this site and you will!

..and remembering that Professore Ernesto has two terminal doctorates aimed specifically at making coffee will help your self esteem in the meanwhile.

[cannonfodder]

Time has taught me that the best indicator (aside taste) of espresso quality is visual. There comes a time when you can watch an extraction and look at the cup and anticipate what you are going to get. Based on the flow and crema you know when it will be bitter, sour, burnt, flat etc...

I believe Jim put it best when someone asked a similar question. His reply was essentially, If you stop the extraction and are left with a pale dot in the crema from the streams, you went just a little to long.


Good


Couple seconds too long, light crema dots

[another_jim]

If you stop the extraction and are left with a pale dot in the crema from the streams, you went just a little to long.

Heather Perry trains beginners to stop when they see the pale dot(s), especially when using a non-naked PF. She says in her experience giving training sessions, beginners cut too soon when judging color for the first time. I'm pretty certain she's right, since the right flow color is a bit hard to describe, and it's the pale dots that first got me looking at the flow before there was anything posted on the topic.

[Dogshot]

It is possible to hack the PF of your Saeco to non-pressurized status. My friend did this with his without cutting or breaking anything (in other words, it is reversible). However, after tasting his results, he plans to cut the plastic and make it a more permanent state. Here in the Great White North, Saeco's non-pressurized PF is about $60, which seems to be a bit of a rip-off. By the way, have you ever removed the 3 screws holding the plastic handle and spout and taken a look at all the accumulated oil and coffee grunge that the espresso pours through before reaching your cup? Those PFs should be unscrewed and cleaned daily.

[jovial]

right... time to see some photos before I go about depressurising my filter basket.

Dogshot, I don't know about Saeco, but with Krups, the filter baskets themselves are pressurized. the filter-holder is not.

So, this is it!.
This is as best I have been able to achieve so far.


The one on the right is an under-extracted shot, poured in 16 seconds.
Mind you 16 seconds, is an achievement with a pressurized filter-basket..... normally they pour in 8 seconds!

The one on the left poured 80% for 18 seconds and then just stopped. I didn't see any drops for next 5 seconds, so I turned off the machine (not to damage the pump), and after some kind of release of pressure (or possibly contraction of the brew-head rubber and expansion of the coffee) I got the last drops of espresso filling the glass up a bit beyond the one ounce line. (another_jim, how do u like this is an attempt for destructing the machine? lol)


So, this is a typical good shot that I try to get more than often. It goes over an ounce quite often, but I try to get the 22 seconds extraction time at least. And occasionally it does happen that after the 18th second the pump just stops (i don't know why! can the coffee still expand at that stage?)


As you can see, I have to get the grind very fine to be able to block the machines flow and pressure.... Almost always I have coffee fines in my shot glass or coffee. I'm ok with it though.


This is the kind of pack you end-up with. I have to always up-dose the coffee, otherwise the coffee expands too much and channeling occurs.

So, any comments? i'll try to get some photos after depressurising the filter baskets as well, so we can compare.

[another_jim]

I think the restrictor is clogging when you go beyond a certain grind fineness -- it happens on DIY temperature measurement gear.

[Psyd]

right... time to see some photos before I go about depressurising my filter basket.

Dogshot, I don't know about Saeco, but with Krups, the filter baskets themselves are pressurized. the filter-holder is not.

So, this is it!.
This is as best I have been able to achieve so far.

Hey, I think that if you match the color from the second photo, the original might have actually looked a bit more natural. If I may, did they look a bit more like this when they were in you kitchen?

[DaveC]

3. Grind fine enough so the above two techniques have the machine dancing on the edge of self-destruction when pulling the shots. According to the Bassett stories, this is quite essential. In any case, the sooner this machine self-destructs, the sooner you can get a proper one.

not very nice for the machine...but

[DC]

Hi Jovial

In my opinion, the event that has marked the 2nd biggest improvement in my espresso making thus far was ditching my pressurised filter baskets (the biggest being grinder/fresh roasted beans of course). After a few initial problems were ironed out I went from making shots that looked like yours to making shots with thick real crema that's closer to being the right colour than before (more importantly, the shots tasted better). You just can't do that with the pressurised baskets because as another_jim says, you don't have the same control over the shot as with non-pressurised baskets.

Also, the shots look like your machine is running a little cool, I don't know if you do this already but I switch on the steam wand for about 20seconds, then run ~2oz of water through the grouphead before pulling the shot.

One other minor thing - those Whittards glasses you are using... I used to think that line was a 1 oz mark but it's not, it actually marks 0.75oz (23ml). The real 1 oz (30ml) line is shown by the black pen mark on this image:



I know its only a minor detail but every little helps eh?

DC