Espresso extraction problem

Wigsy

Can I ask for help please? I am new to this and just bought a Gaggia Evoloution and an Iberital MC2 grinder (after much research and reading of this site). I am using fresh Hasbean beans (Bolivian Machacamara). My problem is that I have already used up one bag of beans trying to adjust the MC2, I am getting a lovely crema but it tastes really harsh (like a metal taste). I have tried different tamp pressures, letting some water flush through before making it and am starting to get a little frustrated.....Has anyone any ideas?

_tony_

Wigsy,

I think I have a similar issue (with a Gaggia Classic though)...

I spent a few hours reading up on it yesterday, I think the machine's pressure (as controlled with the OPV), and temperature is most likely having a huge influence on the coffee you're getting.

I have found the some beans come out really, really harsh for me, and others come out much better - while certainly this is partially due to the beans themselves, many serious coffee people will fine tune brewing temperature for each bag/type of beans. Some will also fine-tune their machines to ensure that it is operating at ~9bar - most/all new gaggias run at 11-12bar for them coffee pod things.

Out of curiosity, did you try using filtered water or spring water instead of just tap water in the machine?

I'm new to all this stuff so I guess some others here can give you more info....

Doodee

Was the machine new or Second hand?

I bought a second hand Gaggia Evolution from Ebay that had been left sitting for some time. Had a similar issue with the Coffee having a metalic taste. Ended up dismantling the machine to clean the group head and boiler and then doing a good De-scaling before flushing a considerable amount of water through the machine.
Haven't had any problems with it since.

also I agree with teh above about using filtered water. Every little helps.

Wigsy

Thanks. Yes I bought it on ebay 2nd hand. I have used filter water too.

Is dismantling the machine to clean the group head and boiler and de-scaling easy to do? Is there any where to find info on how to do this?

Any ideas if changing to 9 bar is easy to do and how to do it?

I found an article today http://www.rocket-espresso.it/downloads/How_To_Espresso.pdf that suggests that it may be from grinding too coarse and giving under extracted coffee. So how do you time the 18-25 seconds guide for an espresso? Is it from when you press play or from when it starts to flow? Also when do you stop the timing? i.e. does the flow have to stay the same colour for the 18-25 seconds and once it changes colour to stop?

Mr Magnolia

Wigsy wrote: »

So how do you time the 18-25 seconds guide for an espresso? Is it from when you press play or from when it starts to flow? Also when do you stop the timing? i.e. does the flow have to stay the same colour for the 18-25 seconds and once it changes colour to stop?

I've had a quick look there and it does't look like this gaggia uses pre-infusion. This means you time your 25 seconds from when you hit the pour button.

Discard your worries over tamp pressure for the minute, pick an average pressure and stick with it.

Pick a particular dose, try 16 grams. You'll get a small accurate digital scales from ebay for a few quid. You will need to know how much 16grams of ground coffee is though.

Fill your basket evenly and tamp as plumb as you can. Flush some water out of the group head before you pour.

Pour 2oz or 60ml of espresso.

By following the above [for the most part] the only variable is your grind. If it's pouring in less than 25sec adjust your grind finer, if it's clogging and taking longer then your grind is already too fine so adjust it coarser.

Doodee

Wigsy wrote: »

Is dismantling the machine to clean the group head and boiler and de-scaling easy to do? Is there any where to find info on how to do this?

Right, This should help you:

http://coffeegeek.com/forums/espresso/machinemods/436367

I'd say just be careful with the plastics when taking it apart, other than that it is fairly easy.

also, When dismantling the boiler make sure to have a Towel down as there might still be water in it that will spill out when you pull the parts apart.

After you dismantle, clean and re-assemble then try flush some water through it, about 3 - 4 water tanks worth going constantly. Don't forget to run water through the steam wand also every once in a while.

If you are stilling the metallic taste after that then I'd Descale. I was advised by Stimpson to leave some of the solution in the water tank for a short period to allow it to work before running it through (Similar to above). The instructions on the packet said otherwise. Tbh, since I no longer have a nasty metal taste he was clearly right!

Best of Luck with it. If you need any other info just gimme a shout.

kmick

Here are my tips from a gaggia evolution.
1) Let machine heat up 10 minutes before use.
2) When the machine is ready run it 2 or 3 times and then clean down anything with any residue on it.
3) I use the Lavazza in the red and silver pack. I found I could never grind fine enough for espresso. Friends said to just keep grinding but my grinder (100 euro gaggia one) just did not seem up to it and my budget was blown.
4) Use LOTS of coffee. I fill about 3/4 of the spout and tamp it down. Then add a little more. If it is too string you can add water but too weak is a disaster - bitter, metallic and acidic. Its called over extraction and its why Bewleys coffee always tastes like muck.
5) Use your coffee quick or dump it. I keep mine in the freezer and transfer small quantities to an air tight container. After about two days I dump anything left in the container. The coffee lasts a month tops even in the freezer.

Gran Hermano

Whilst a Gaggia MM will not grind fine enough you should have no bother with the MC2, a friend of mine is using an Evolution with the MC2 without any problems.

Run some Puly or Cafiza through it a couple of times to clean it out then
follow Mr M's earlier post.

RE*AC*TOR

kmick wrote: »

...3) I use the Lavazza in the red and silver pack....

I was with you right up to there.

kmick

RE*AC*TOR wrote: »

I was with you right up to there.

Maybe not for the connoiseur but I find it gives a good result. I would be happy to try something pre-ground that you can recommend however.

RE*AC*TOR

You might think it gives a good result, I know I probably did, when I was using the very same combination a few years ago, but compared to a properly extraced, freshly roasted and ground coffee, there is no comparison.

Wigsy

Thanks for all the advice. I'm off to get a weighing scales some Puly or Cafiza and seems like it's time for a bit of spring cleaning.

Wigsy

Just a quick thanks. Cleaned out the Gaggia and descaled. Solved the problem. Thanks Mr Magnolia for the tips and Doodee for the cleaning guide.