The Wild Drink Blog

First of all let me start by saying that the CMA Astoria Plus 4 U has been a massive hit. Though I don’t consider myself to have been a real barista for more than a couple of years I have drank a lot of espresso and I can honestly say that the 3rd shot I pulled from the Plus 4 U on the morning it was delivered set a new benchmark in espresso for me. The machine consistently produces amazing shots, of which I had a few too many today… they’re just so tasty!!

Dave and I had a bit of spare time to mess about with the brew temp. functions today so we thought we would have a go at finding the optimum brew temperature for the Origin triple certified blend which I use. The blend comprises of equal parts Colombian, Honduran & Sumatran. Since fitting the machine I have had both group heads set to 91°C and as I already said the results have been fantastic, we kept the same dose & grind, the Mahlkonig K30 is pretty consistent, and altered the groups in steps of 2° at a time. I realise that there are many variables that can contribute to how the end product tastes but I made every effort to keep everything (even down to cup temp.) exactly the same every time and we always pulled at least two shots at each temperature in case of freaky random extractions

86°C

I wanted to try something that would taste different to what I had been drinking that morning so I bumped the first group down by 5°C, the result was so drastic that we immediately extracted another one only to end up with the same shot. The normal acidity of the blend had dropped a considerable amount and been replaced by a lot of body and and earthiness that really reminded me of sweet warm soil. It seemed to me that lower temperature was somehow highlighting the Sumatran Lintong in the blend with its characteristic earthy full body.

88°C

This temperature was beautiful. The earthiness had diminished slightly but a freshness and acidity had become apparent and we really enjoyed the espresso at this level. I found the body to still be lovely and syrupy, the new found acidity turned the earthiness to fruity nuttiness for me.

90°C

At this stage we found the body start to drop off slightly, it was as if the South American contingency were beginning to take over with a lightness and more punchy acidity. This was still a great espresso and highly drinkable.

92°C

Once we tried a shot at this temperature I was shocked at how light it had become in only 6°C, I could not believe how much difference there was. We kept pulling more espresso at 92°C and 88°C just to marvel at the contrast. At 92°C the acidity had really kicked in but was not unpleasant, we were also loosing some of the rich sweet earthiness and the amazing body from the Sumatran.

I decided not to take it any higher than 92°C we had lost a couple of things that are great about this coffee and I was pretty sure at higher temps. we would only continue to loose the body of the espresso. 88°C & 90°C were my favourites so we tried in between…

89°C

At this point I was slightly concerned that we would pull an espresso that would highlight all the stuff we least expected it to, unbalanced, high acidity, rancid etc. - But fortunately it didn’t, we got a shot that was extremely well balanced in my opinion with all that body but a good acidity to structure the flavour nicely. So we stuck with 89°C.

I simply could not believe how black and white the results were. I was in such disbelief that I started pulling shots at random temperatures and handing them to Dave to guess the temperature form the character in the cup, incredibly (to a certain extent) he was able to tell me at least which end of the scale they were at and it was easy to see how.

After a lot of espresso I started to feel a bit sick but I was thrilled that we had not only found a great temperature to brew at but also discovered the amazing difference that a couple of degrees can make to a coffee. I realise that there is a lot of science involved in this, mainly to do with solubles yield and the rate at which different flavour profiles disolve but this experiment was really about practical results, i’ll need to read a bit more before i’m ready to write about the science!