The impact of temperature on the flavour of coffee.
In the last couple of newsletters I've made mention of techniques used by World Barista Championship entrants in recent years. The partcular technique I'm referring to today is referred to as extract chilling or compound chilling. The essence of the approach is to extract espresso as per normal, but immediately cool the extraction so that volatile compounds (which happen to be highly aromatic) remain in the liquid rather than being lost to the atmosphere.
Well, I tried it... and I'm excited... extremely excited. The photograph above shows a simple A/B test. I tasted the same espresso split between two cups, one utilising the extract chilling technique and the other as per my normal espresso making routine. I found that extract chilling made a significant and positive difference to the coffee accentuating the coffee's high notes (generally florals and fruits) and improving the overall texture of the espresso (I didn't expect that!). (To the statisticians out there, I apologise that this test was not double blinded). This is a great reason to make your own espresso at home, it's just not cost effective for a café to offer this service!
The methodology is very simple. In the left cup you see a tea strainer holding a stainless steel whisky ball which had been in the freezer overnight. I made my espresso using my standard routine. That's it. Total expenditure for was in the order of $30 for the largest upgrade in espresso quality I've experienced in years. I'm hoping that some of you give this a go. If so, please do let me know your findings!