What is the big deal over grinding coffee at home? K.. so many reasons! And I’ll start at the beginning and I’ll try not to ramble on too much. So hypnotically you buy your coffee from your fave roaster. You assume the coffee is delish and fresh and it should taste just as good at home as it does in the café. You ask them to grind it accordingly. You bring it home, you make a cup of coffee and its good but its not great and the longer time goes on the more bland your coffee becomes. SO MANY things hinge on a good cup of coffee… the temperature of the water, the size of the grind, the ratio of water to coffee bean and the coffee itself for example.
So you obviously buy fresh coffee from a roaster for a good reason… it tastes good! Its waaaaaaayyy better than (Insert gross coffee of your choice here) So here are some reason why we should grind coffee right before we consume it!
Coffee oils are delicate, which makes them an easy victim of contamination. Whatever odors are around ground coffee will taint it in ways that will not contribute to your coffee tasting experience.
The cells inside the roasted coffee bean contain approximately 1,000 different volatile aromas and flavors. Once ground the volatile aromas are immediately released and they react with oxygen in the air (oxidation). After 10 minutes ground coffee loses about 60% of its aroma.
Coffee oils are water-soluble. That’s a good thing or we’d have a very had time trying to get the oils out of the bean. This fact however poses a great problem for ground coffee. When ground coffee is exposed to moisture in the environment it immediately starts to dilute the oils.
4) Carbon Dioxide Depletion
Increased surface area permits for greater carbon dioxide (CO2) gas liberation. During the roasting process a lot of CO2 is created. Since the bean is porous, some of it is lost during the cooling process. Much of it, however, is retained within the cells of the coffee bean. This CO2 plays an important role in that it is the main method for getting the essential coffee oils into the coffee once they are released.
The problem is that the increased surface area created after grinding permits for greater CO2 gas liberation. In fact within 60 seconds of grinding 80% of this gas is released into the air.
So there’s that… lets talk about grind size… depending on what kind of coffee brew method you are using, you have to adjust the size of the grind accordingly. So for French Press you’ll want a coarse grind and for espresso you’ll want a fine grind. Basically someone else did all the work and figured out what size of grind for what brew worked best and tasted the best. Makes sense, right? So why are some grinders like $20 and why are some like $5000? Basically any coffee grinder is prolly better than pre-ground coffee. I feel like I could write a whole other article on grinders … so I’m going too! But just keep in mind that the more accurate you can adjust your grind… the better.
I’ll leave you with that! More about coffee grinders soon!