I have just changed from an espresso blend to Sumatran Mandheling. Previously I was using 14 g of coffee at a 30 s extraction to get a nice balanced cup. Then I changed beans. What I got was sour, to the point, I wondered if the milk I was using was off - it was n 't. So I kept the grind the same and upped the dose to 15.5 g. The extraction time increased by about 30 s. However what I tasted was the closest i think it is possible to come (on a Bacchi) to a Godshot. Really layered and exapansive flavour and great body too.

Now looking at the effect of all of this on the extraction time, that is, doubling it, I can only conclude that I made the shot more bitter and that somehow offset, and combined with the sourness, to create a great new flavour combination.

Does this sound like it makes sense? Or am I missing something obvious?

A 60 second extraction seems waaay too long, but you say it tasted good so how can I argue with that?

But as a general rule, the first 1/3 of a shot is acidic & sour, the middle sweet but somewhat bland, the last 1/3 more watery/weak, and bitter. And yes it does all come together to balance out. You corrected your shot by adding some of the weaker bitterish stuff, but probably also ensured that you extracted all the sweet caramels as well.

You don't mention volume of your shots. That would determine where I would go from here. I'd try to get the same or better results in 30 seconds instead of 60.

I have been overstating the extraction time. Maybe it's more like 45-50 seconds, instead of 60. I feel that some sort of balancing out is taking place.

Ian_G wrote:Now looking at the effect of all of this on the extraction time, that is, doubling it, I can only conclude that I made the shot more bitter and that somehow offset, and combined with the sourness, to create a great new flavour combination.

Does this sound like it makes sense?

It's hard to comment without tasting alongside you, or, at the very least, making some measurements with an espresso refractometer. In general though, shots that are significantly underextracted tend to be sour; in the mid-range, they are well-balanced; when overextracted, they tend to be bitter.

You doubled the water/coffee contact time; increased time tends to raise the extraction level. So you may have gone from an underextracted state to a balanced one. To me, this explanation is more plausible than thinking that adding bitters to sours would in itself make the shot taste better.

A corollary is the fact that for me, the 21-30 second extraction "rule" often misses the mark. I regularly get 45-50 second extractions that taste better to me than the same coffee pulled at 25 secs.

Some coffees release their solubles with apparent reluctance. For them, it may take a finer grind and more contact time to get the job done.

AndyS

What you say makes sense. I'm now wondering about the 30 s guidance, and if it is in fact an average. A sliding scale, weighted toward longer extraction times might make sense for some coffees. This particular coffee seems to only be drinkable at a fine grind and a longer extraction time.

But I don't have sufficient experience to say whether this is to be expected or not. It's the first time I came across it.