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Extraction Issues

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The espresso from my Classic seems either bitter or sour. I am adjusting the grind but can't seem to hit the sweet spot. I am grinding Rave Moka Java with my Mignon so should not be expecting too much bitterness. Any ideas? Very frustrating! :-)


Gaggia Classic (Pre-Phillips) With Silvia Wand Mod

Eureka Mignon Grinder

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Ok do you weigh in and weigh out dose and extraction to the 0.1g ?

Are you keeping your dose the same when adjusting the grind if so to what?

How long is the extraction , when it is blonding

Do you temp surf ? If so how ?

Is your PF warm when you pull a shot ?

It is more than likely one or both of the extraction temp or the grind and dose

Answer to the above will help people see which it is.

Edited by Mrboots2u

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I preheat for c30 mins and weigh 17g in. The extraction seems too fast, or very bitter!


Gaggia Classic (Pre-Phillips) With Silvia Wand Mod

Eureka Mignon Grinder

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Ok what's coming out( extraction in weight ) and in what time

are your scales measuring to nearest gram or 0.1 g

too sour - temperature too low or grind to coarse and extraction too fast .

too bitter temperature too high or grind to fine meaning extraction coming out too slow .

Plus When are you pulling the shot ? are you doing some form of temperature surfing ?

cant really help without more info?


I write a blog, it's nothing to do with coffee ...

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Scales are to the nearest 0.1g. I will weigh input and output tomorrow. I do not surf before extraction however. Once the pf is hot, should I pull water without the pf until the light goes out before pulling my shot?


Gaggia Classic (Pre-Phillips) With Silvia Wand Mod

Eureka Mignon Grinder

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Scales are to the nearest 0.1g. I will weigh input and output tomorrow. I do not surf before extraction however. Once the pf is hot, should I pull water without the pf until the light goes out before pulling my shot?

 

Urban- Charlie , classic owners can you help re temp surfing routine for a classic ?


I write a blog, it's nothing to do with coffee ...

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Without some temperature readings surfing is about consistency rather than getting the correct temperature. If you flip the switch at the same time in the heading cycle every shot you'll be consistent. An easy place to start is as soon as the ready light goes on. That way you're (close to) the highest temp in the heating cycle. It's as accurate as the thermostat in the machine. Which is probably not very.

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Without some temperature readings surfing is about consistency rather than getting the correct temperature. If you flip the switch at the same time in the heading cycle every shot you'll be consistent. An easy place to start is as soon as the ready light goes on. That way you're (close to) the highest temp in the heating cycle. It's as accurate as the thermostat in the machine. Which is probably not very.

 

That's what I used to do, pull some water through the group until the heater comes on (light out) prepare the grinds and wait for the light to come on which means that you are at the "correct" temperature. It's a good starting point and at least you should end up being pretty consistent between shots.


DE1Pro, EK43 SSP, bloody tasty coffee!

GrindScience.com - My blog of coffee related ramblings

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Also the mingon is a pretty clumpy beast from my memories so you might be dealing with an uneven extraction which would lead to under extraction and sourness, maybe a little stir in the basket could help break it up and get a more even extraction?


DE1Pro, EK43 SSP, bloody tasty coffee!

GrindScience.com - My blog of coffee related ramblings

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Thanks for the advice guys. I do stir my clumps (!) so the next item in the list will be temperature. Will check in again tomorrow :-)


Gaggia Classic (Pre-Phillips) With Silvia Wand Mod

Eureka Mignon Grinder

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Regarding temperature surfing on the Classic my best shots have been using the steam switch to raise the water temperature , with the brew light on flip the steam switch on for a count of 3-4 seconds then turn steam switch off and count 3-4 seconds - pull the shot.

Just experiment with the above method varying your count, try a 3 second count first then a 4 second etc.

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Thanks for the advice guys. I do stir my clumps (!) so the next item in the list will be temperature. Will check in again tomorrow :-)

 

Good luck! You should be able to get great espresso from that set up :)


DE1Pro, EK43 SSP, bloody tasty coffee!

GrindScience.com - My blog of coffee related ramblings

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Re the advice about flipping the steam switch on to raise temperature, I would personally advise avoiding doing that at all. The advice you have got so far re temp surfing is a good starting point, the longer the warm up you give the Classic the more stable the temperature becomes, although as ever intra shot it needs a little time to recover temp as cold water has been introduced into the boiler. I would advise getting a timer switch and have the machine switch on around an hour before you get up in the morning, if you get an event based timer you could also have a pattern of on and off times throughout the day. I simply used to have mine come on an hour before I got up and left it on all day, with the timer switching it off around 10pm, this seemed to do away with any need to temp surf.

 

Basically temp surfing is about pulling your shot when the heater is just below the top of it's heating cycle so that it will stay on through the shot, thus, keeping the temperature more stable. As long as you keep as many parts of the process as constant as you can then the easier it is to troubleshoot your shots.

 

I would also advise getting something that has big bold flavours, yet is easy to work with to make defining your issues easier, to many peoples surprise I would suggest Has Bean's BRAZIL FAZENDA CACHOEIRA DA GRAMA YELLOW BOURBON PULPED NATURAL, check it out on their website, it's more of a medium roast than a dark one but it may help you try and work out what sort of flavours you are trying to achieve.


Common sense is not a gift, it's a punishment. Because you have to deal with everyone that doesn't have it !!!

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Interesting advice thanks. When I have stumbled across a decent shot the Moka Java seems a bit light so I will go for Rave Signature next I think. More surfing tonight!


Gaggia Classic (Pre-Phillips) With Silvia Wand Mod

Eureka Mignon Grinder

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When I had my classic I did try temp surfing but never really got on. I personally would just leave the machine nearer an hour before starting. The biggest improvement I found came when I stopped using too much water!! By that I mean when I stopped flushing an oz or 2 to get the boiler to cut in or preheat cups I found my output much more consistent.


Brewtus IV, MSJ, Torr 58.4 Convex, Hausgrind, V60-02, Aeropress, CCD, Bodum French press

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That's what I used to do, pull some water through the group until the heater comes on (light out) prepare the grinds and wait for the light to come on which means that you are at the "correct" temperature. It's a good starting point and at least you should end up being pretty consistent between shots.

 

That's what I do with my Classic.

 

Definitely weigh the output and let us know what you put in, get out and time.

 

From using the set up I think it might be a distribution issue. Are using a yoghurt top top and are stirring with something like a unbent paper clip.

 

If your still struggling, post a clip of the shot prep and pulling the shot.

 

It will give us an idea of what's going on.


Sage DB; Mazzer Major; VST 15g, 18g & 20g Baskets;TORR Trapez & Perger Tamper

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Copied from the Gaggia Users Group website written by the Gaggia Classic wizard D4F.

 

Heat Before Brew

 

Temperature in the water lags the boiler since the elements are in the boiler wall unlike most machines. A pre-brew bump of the steam switch for about 3 – 4 seconds, followed by a rest of 3 – 4 seconds, and then brew will help. The heat in the boiler wall will absorb into the water about the time water starts to exit and cool water enter. This is one of the most important steps for better brew and cup temperatures. Think of matching cool calories (water) to heat calories.

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Copied from the Gaggia Users Group website written by the Gaggia Classic wizard D4F.

 

Heat Before Brew

 

Temperature in the water lags the boiler since the elements are in the boiler wall unlike most machines. A pre-brew bump of the steam switch for about 3 – 4 seconds, followed by a rest of 3 – 4 seconds, and then brew will help. The heat in the boiler wall will absorb into the water about the time water starts to exit and cool water enter. This is one of the most important steps for better brew and cup temperatures. Think of matching cool calories (water) to heat calories.

 

The basic issue is the thermostats on a Classic have such a wide deadband you can't guarantee that your Classic will behave like his or anyone elses, the bottom line is that these machines weren't meant to be made to heat up this way, my best results based on 7 years of owning a Classic came when I just left it on all day rather than expecting it to be used in the same way you would a kettle, rather than any elaborate rituals people invent to convince themselves they are making things better for themselves.


Common sense is not a gift, it's a punishment. Because you have to deal with everyone that doesn't have it !!!

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Weighing my output it seems I have been way over extracting. Whatever happened to a double being 2 oz?! :-)


Gaggia Classic (Pre-Phillips) With Silvia Wand Mod

Eureka Mignon Grinder

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Weighing my output it seems I have been way over extracting. Whatever happened to a double being 2 oz?! :-)

 

Yeah exactly!! Maybe that's why high street coffee tastes so bad ;)

 

I would suggest getting your output right then if still not happy then try temp surfing.


Brewtus IV, MSJ, Torr 58.4 Convex, Hausgrind, V60-02, Aeropress, CCD, Bodum French press

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Weighing my output it seems I have been way over extracting. Whatever happened to a double being 2 oz?! :-)

 

Go finer on the grind then keep everything the same and you should extract less. 2oz by volume is the traditional Italian guide.

 

My shots can be anywhere between 1-1.5oz by volume. Go with weight it's a better guide


Sage DB; Mazzer Major; VST 15g, 18g & 20g Baskets;TORR Trapez & Perger Tamper

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Interesting advice thanks. When I have stumbled across a decent shot the Moka Java seems a bit light so I will go for Rave Signature next I think. More surfing tonight!

 

Urban gives good advice above.

If you hit that 1.6 ratio as a starter and it still tastes light , then try increasing your dose and hitting the ratio again

If you increase you dose you may need to coarsen the grind a little to not the same weight extraction in the same time

This of course depends on what you are currently dosing . I wouldn't go above around 18g in a stock basket for a classic , otherwise your are in danger of over dosing and not Being able to lock the PF in.

Let's us know how you get on


I write a blog, it's nothing to do with coffee ...

https://rjwinc.wordpress.com

Instagram - rjw_inc

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Getting there... :-)


Gaggia Classic (Pre-Phillips) With Silvia Wand Mod

Eureka Mignon Grinder

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Sounds like you're getting great advice about temperature and extraction. Just thought I'd respond to your first posting where you said 'bitter or sour'.

 

You'll taste sour at the sides of your tongue; it's that taste that makes your cheeks tighten. That's usually low temperature or water moving through the puck too fast. That might be too loose a grind leading to too fast a shot or (for me at least) more often it's faulty distribution (see below re Mignon clumps).

 

You'll taste bitterness centre back of your tongue. This is a more complex thing but often seems to me to be about over-concentration: you grind really fine and get a very slow shot; or your temperature is high so you are leaching more than you want (over extracting) out of the finer grinds.

 

Faulty distribution: this is about taking care building the dose in your portafilter and there's no harsher judge than a naked portafilter and a VST basket. But it's also about the quality of your grinder. If it delivers sticky clumps it will be harder to get an even extraction. Your grind may actually be too tight but the water finds a way through the puck leaching nasty flavours as it speeds through. When I first got my Mignon I used a tiny basket whisk to beat the grinds in a glass before transferring them to the PF. It was the only way I could get an absolutely even pour. As the grinder aged it just got better and better until it produced completely clump free grinds so hang in there.

 

Bitterness: this is less straight forward. As I understand it - and being ever mindful of the expertise that dwells in this forum...

 

If your shot is pulling evenly and taking c.35s for about 1.6 x your dose weight but you can taste woody, smokey, organic chemical type flavours then you may be extracting at too high a temperature and getting roast driven rather than bean driven flavours. Flush more before your shot.

 

If your shot is pulling evenly and taking the right amount of time (35 or so seconds from starting your pump to hitting 1.6 x your dose weight) but it is really concentrated and just beating you over the head with cloying flavour then try reducing the dose but tighten the grind a bit to keep the extraction time right. Keep taking the dose down in small increments until you get a shot that is neither sour nor bitter. I prefer not to go more than 1.5g below the weight the basket was intended for so if I need a 16g dose I'll switch from a 18g basket to a 15g (this avoids sloppy pucks if nothing else).

 

Once you have a balanced shot you can play with brew ratio and grind to try to draw out the character of the bean as the grower and roaster intended. That's a whole 'nother order of discussion though.

 

I'm now living in fear of the edits and corrections that will follow from the many infinitely more expert members on this forum. :)


Espresso: Ceado E92 (modified for single dose); Vesuvius; VST baskets and refractometer.

Other: Aeropress, Sowden and Alessi Moka Pot; Mazzer Robur doser with Auber timer; Mazzer Mini E; Expobar Leva Dual Boiler

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