Espresso Roast or Full Roast – Which is best?
Ok- so the preparation of a great espresso depends upon:
The cleanliness of your machine
The correct pressure / temperature of water and time for extraction
And of course the original coffees used in the recipe
Finally, grind size and of course roast colour, or the degree to which the beans are cooked, is an essential part of the mix often over looked by the casual drinker
The shortest possible roast time is c. 90 seconds – This is called a High Yield roast, in which the beans are exposed immediately to a high temperature and subsequently ‘blow up’ like pop corn. This process delivers c 15% more surface area for the extraction of soluble solids when brewed… and you won’t be surprised to hear is mainly used in catering and vending
Typically, supermarket beans are roasted for between 8 – 12 minutes…
And for espresso roast or slow roast anything from 15 – 25 minutes is possible
In all cases, a peak temperature of c 225 > 230 degrees Celsius is attained… and at this critical point the roasting process is immediately stopped…either
with an industrial quench of water – sprayed directly into the roaster – or by the beans being emptied on to a cooling tray which is gently turned by a paddle
Both methods of cooling have their pros and cons… The quench method adds moisture back to the bean. Typically, raw green beans have 9 – 15% moisture…post quench they can legally have up to 5% moisture. The re addition of moisture, some suggest, affects the production of and longevity of the espresso crema…..not so sure it really matters much…!
The dry / paddle cooling method doesn’t add any moisture back, but the agitation of the bean can encourage broken beans…not so pretty…but a fact which does not affect the quality of the liquor
We use the paddle cooling method…so rest assured you are not buying 5% water!
We also use a convection roaster…considered ‘top dog’ at the moment in the trade…
As I am an old stick in the mud, I actually prefer the drum roast conduction method…I think it gives a more evenly cooked bean……Problem is these roasters are as rare as hensteeth…but I happen to know a man ….!So watch this space