How to make good espresso?

[hongwei]

Hi all,

I have look through some thread topics which looks quite similar to mine, but I don't see any answer that is close to what I am going to ask that's why I am starting a thread here.

To start with, I have got myself a semi auto espresso machine recently and I am trying to do a good espresso and cappuccino and here is the problem that I face.
I got a taste for my espresso that is bitter at the same time sour, to be exact the bitterness is more than the sourness. Is this over or under extraction?
Following are the technical details of how I got my espresso: a volume of slightly less than 1 oz, I don't know the temperature but I assume that the temp for a semi-auto espresso machine should be quite standard, the appearance of my espresso immediately after the extraction is that half of the volume is the crema and the other half is the coffee (is this proportion normal), the extraction time is 30 seconds and using a 2 head portafilter, the amount of coffee powder is filled up to the brink of the portafilter and tamp to about half a cm lower. I don't know if the above amount of information enough but if not please let me know and I am very please to provide more.

So my question here is whether what have went wrong, that causes my espresso to be bitter and sour? What are the variables which I need to take note of?

For all kind coffee lovers, please help me in this area.

Thanks in advance.

Kelvin

 

[CCafe]

A few things.

14 grams of espresso for a double. If you overfill the double basket and tamp it, I almost guarantee that you have between 15 to 20 grams packed in. So weigh your espresso. Fill the basket and level it off with a knife. This will most likely put you around 13.5 - 15 grams.

Generally you want the water temp 210F - 230F for the first few seconds only to cook the espresso then the water temp should drop around 200F for the rest of the shot cycle. Most commercial espresso machines do this automatically by the design of the group head.

If you have a little home unit it needs to pumping at least 200F.

What brand and model of machine do you have?

 

[hongwei]

Thanks for the reply.
The machine is Eroica 2 group 9 litre boiler.
I don't know if this machine is like what you said where temperature will change according to the time.

I will try to weigh to see if it is within the weight mention.

 

[Alun_evans]

I would say 30 seconds woul be over extracting for a single, but reading your notes it seems you were using a double portafilter? Generally bitterness in the cup can be directly traced back to either the grind, the tamp or (if all else fails) the blend of coffee you are using. Dial in the machine using the single portafilter and aim for 1oz shots using a shorter time frame- 23-25 seconds would be the goal. I think you are right in assuming temperture would be the last variable to look at- after grind, tamp, pump pressure etc. Check the type of coffee you are using in the machine. An espresso blend which is old, not fresh, will produce rancid characters in the cup that can also be interpretted as bitterness. Of course the coffee you are using may be robusta rich- which again results in some bitterness, pop-corniness in the shot. Good luck.

 

[ElPugDiablo]

Is this the machine?
http://www.espressomachines-it.com/macc ... oica1.html

Do you temperature surf (dump the hot water that is made too hot by the heat exchange)? If you have sour and bitter espresso you might want to grind finer and temperature surf a little longer. I agree with weighting your grind and try for 14 grams to start and experience with a little less or a little more.

Also do you use dark and oily coffee? Darker roast usually produces bitter espresso.

 

[NW JAVA]

Coffeeegeek.com I'd recomend you try that.....