Fresh Ground Coffee vs. Pre-Ground
Ever since I started on my home coffee brewing journey and discovered the world of coffee beyond those high-street coffee chains, it’s been drummed into me time-and-time again that fresh ground coffee is better than pre-ground coffee. To be honest, back then I really didn’t know why, but over the years and thousands of cups of coffee later I have accepted this logic and truly believe that freshly ground coffee is better – but why?
If you have ever wondered if grinding your whole bean coffee the night before or even grinding up a batch for the week ahead makes any real difference to the taste, then this article is for you.
Factors That Can Affect Your Coffee
The world of coffee is a minefield of bogus claims and it’s often difficult to differentiate between fact and fiction. However, when it comes to fresh ground coffee vs. pre-ground there is strong evidence to back up the claim that fresh is better. Just like any other perishable food product, the longer it sits on the shelf of your pantry the less fresh it will be (it’s not rocket science). The same applies to coffee beans, however, by grinding them up early you will only hasten their loss of freshness.
When it comes to prolonging the life of your coffee there are three factors that contribute to their speedy degradation – oxidation, moisture, and CO2. Let’s take a look at these three factors and how they can adversely affect your coffee.
If you could take a look into your coffee beans you would find complex compounds. It’s these compounds that help to give your coffee its flavor and aroma. The problem is that most of these compounds lack stability, which means that any outside element such as air (oxygen) can adversely affect their state and they can then change very quickly. This process is called oxidation. When the compounds of the coffee come into contact with air molecules they then create new molecules and it’s this process that speeds up the loss of those desirable aroma and flavor compounds found locked inside of your coffee beans.
When you unlock the flavor and aroma from your coffee beans by grinding them up you are inadvertently kickstarting this oxidation process. However, it’s not all doom and gloom, this is actually a good thing if you intend on brewing your coffee straight away.
Oxidation will carry on whether your coffee is ground or whole but being ground simply speeds up this process.
Coffee beans are packed full of water soluble oils, it’s these oils that enable us to enjoy our fresh brews through taste and smell. Water solubility is a great thing, however, it doesn’t take a kettle of boiling water to dissolve these precious flavor filled oils, even moisture in the air can steal those oils and ultimately dilute your beans.
So simple humidity in the air or even exposing your delicate coffee beans to your home’s air conditioning can sabotage their integrity. But when you grind up your coffee beans you create more surface area for the moisture to dissolve those oils.
Think of CO2 as the vehicle that helps to transport the oils from your coffee beans into your cup. When you grind your beans you then create more surface area for the CO2 to escape. Less CO2 means less flavor in your final brew.
Whole coffee beans are already very porous, so by grinding then up prematurely you are only makings things worse. Even incorrect storage of your coffee beans can speed up the loss of CO2. So if you pre-grind your coffee and let it sit for days or god forbid weeks you are essentially wasting the one mechanism that’s responsible for your coffee’s great flavor.
It’s Always Better To Grind Fresh
So if you haven’t already come to the conclusion that fresh ground coffee is best and need a bit more convincing here are some science-backed facts.
- Whole coffee beans will stay fresh roughly three times longer than pre-ground coffee.
- Pre-ground coffee can become tainted by other odors floating around your kitchen. Want onion flavored coffee? You better not dice up an onion near pre-ground coffee.
- The flavors are locked inside of the coffee beans don’t let them out too early.
- Coffee and oxygen are not friends when you grind your whole bean coffee to early oxygen will penetrate those beans much faster than if they sat in their original state.