I'll have a go but if I get it wrong some one join in.
What grinders are most popular?
It really depends from country to country, each have there own co ordinators who arrange all of the set up for the competition. Add to this that it goes on in the back room.
What kettles or water towers are used? and at what temp?
How fresh is the coffee?
Roasted the day before, sometime the morning. They are working on very tight deadlines for say the top ten which may not even be known until Thursday afternoon, for cupping Friday
Is it always roasted a little lighter regardless of the region, growing altitude or varietal?
Across the board a guide is set for the roasts and samples are set out for visual inspection. In Bolivia last year we had argatron readings too.
How long do the jurors wait before breaking and how is that managed when twenty coffees or more are on the table?
4 mins and then you go like the wind. It annoys a little sometimes on a table (which you share) when someone goes slower. But on the whole people keep up with each other.
How strict are they at controlling the factors and how many people are assisting with it?
There is a team that apply the water at the same time, and as much is done to control any external factors
What grind size and dose? Do these change depending on the coffees?
Weight I think is 16g but this is from memory. Grind is as unformed as it can be and a course jug like grind
Is there a standard cup size?
There is no standard and again varies from country to country co ordinator, something I think should be standardised.
Are the cups preheated?
Under what circumstances will jurors be able to require a re roasting of another coffee? I'm particularly curious with this one. I've heard that a good cupper will predict the profiles but surely we can expect some coffees to improve at darker roasts? Or is it a case that if it doesn't stand out from the start then it won't later?
If there is a consensus that the roast effected the scores given a decision would be taken to re roast. I think when you have over 60 coffees to evaluate its only fair that they all get the same chance. The levels of experience at COE Jury can vary like wildly (for god sake they let me go), and anything that could slightly sway a coffee either way is not fair to all the farmers hard work.
As a side note although the jury skills can vary I think that overall it gets balanced out, to produce for my mind the best tool to promote fine coffee.
Sorry If I've got anything wrong feel free to chip in guy (and girls)