A lot of coffee experts talk about the 'bloom' of coffee- but what is it? Why is it important? Like so much of the terminology around the mighty bean, it sounds a lot more complex than it actually is!
When we talk about 'bloom' on coffee, this is because the roasting process traps carbon dioxide within the bean. When the bean is ground and water added, this releases the carbon dioxide (also known as 'degassing'). If we don't allow ground coffee to bloom before preparing, there's a real risk of the coffee tasting unpleasantly bitter. Carbon dioxide also repels water during the brewing process, so by spending an extra bit of time on prep by blooming the coffee and removing the carbon dioxide, you're allowing the water to brew properly- and this will give you the very best cup of coffee.
Despite the science behind it, achieving a bloom on your coffee is very straightforward and quick: pour a little freshly boiled water in a circular motion over your ground coffee. It will start to expand and bubble a little- this is the bloom! It may take a moment for this to subside but once it has, you can then begin the brewing process as normal.