Too hot!

I was out for a meal last Friday at one of my favourite beachside restaurants. The meal had been excellent, however the cappuccino was awful, and, yes it was our coffee. I was mortified, the coffee tasted thin and burnt, and on top of this I had to wait 5 minutes before I could drink it because I was in danger of getting 3rd degree burns; it was so hot.

This troubled me all weekend trying to work out what was wrong. I knew the coffee itself wasn't particularly darkly roasted, which sometimes can be a problem, no something else was going on here.

When I arrived on site today, I was expecting one of three scenarios. Firstly that the machine was building up excess pressure when not being used, and this was then firing the water through the coffee too quickly, burning it, and giving it this thin taste.

Maybe the grinder was set incorrectly and this was resulting in badly overextracted coffee.

Or thirdly the machine and its group handles were badly in need of a clean.

Well it turned out to be none of the above!

The machine was perfectly clean, there was no apparent excess of pressure when you first made a coffee, and the grinder seemed to be set correctly.

The give away was the temperature of the water coming out of the group head. Thankfully I had a thermometer with me, so by sticking a probe up inside the group handle I was able to check how hot the water was when it hit the coffee.

All things being equal, the water should be coming out at anything between 88 and 92 degrees Centigrade. As I ran the water, the numbers just kept going up and up. The thermometer raced through 88 degrees, and didn't stop rising until it had reached 96 degrees, before falling again as cold water replenished the boiler.

Eureka! - At this temperature, the water was simply burning the coffee and delivering it straight into the cup.

The problem tends to occur only when the machine has not been in use for some period of time. The temporary solution is to ensure that a good couple of cupfuls of water are run through the machine before making a coffee. The long term solution is to reduce the average temperature of the boiler which is easily done by an engineer.

Finally the other point to highlight is that if you are just making a coffee for one person, ensure that the portafilla is full of coffee. That may sound obvious, but in the heat of the moment it can be easily overlooked.