Why pre-ground coffee stales so rapidly
When it comes to fresh roasted coffee, everyone is on a journey of learning and discovery.
There are some coffee enthusiasts who are well advanced with deep levels of experience. Others may be at the beginning after recently transitioning from instant or pods/capsules.
Generally speaking, Australian coffee drinkers are well informed about the benefits of coffee freshness and quality compared to many other parts of the world. In fact, Australian coffee drinkers are some of the most knowledgeable.
It's also no surprise that Australia's coffee market is already well developed and mature and that's due to a highly competitive industry on the supply side.
It was around 13 years ago that specialty grade coffees began appearing in premium Australia cafes.
These days it is easy to purchase coffee across a wide spectrum of qualities, freshness and value.
This can range from low grade and most likely stale supermarket offerings up to expensive single origin fully traceable micro lots from coffee retailers operating in niche segments.
Consumers have continued to purchase premium espresso equipment for prepare coffees at home. Some of this equipment has capability to match quality cafes.
However, there is still a large segment of the coffee market needing pre-ground coffee in decent quality grades.
Just because it is ground does not mean the quality should be lower.
Whether it's a lack of bench space in a kitchen to accommodate a coffee grinder, or the hassle and mess that comes with grinding coffee on demand, ground coffee is a segment that remains a vital part of Australia's coffee industry.
It may come as a surprise to most customers purchasing pre-ground coffees to learn that pre-ground coffees have a very short lifespan.
Even in sealed, unopened packs, the pre-ground coffee goes stale rapidly compared to whole beans.
When coffee is retained as a whole bean, the cell structure provides a basic and limited degree of protection to preserve volatile compounds we associate as the "essence" of fresh roasted coffee.
Mostly, this cell structure in whole beans preserves intense aromatics and desirable attributes such as body, flavor, sweetness and acidity. When roasted coffee is ground, these attributes are released and exposed to rich levels of oxygen and different atmospheric pressure conditions.
So let's unpack that last paragraph.
Whole beans have a limited, yet far superior ability to retain much of what we love about fresh roasted coffee. They will last up to 15x longer than pre-ground coffees, of course depending upon the storage integrity and ambient temperatures.
But once that whole bean coffee is ground into thousands of smaller particles, exposing tiny cell structures to rich oxygen it rapidly accelerates degradation of the coffee's attributes via oxidization and initiates transformations of the ground coffee particle.
If you leave ground coffee long enough, and here's where you may be surprised to learn or discover, basically inside of 15 minutes, almost 85% of the active volatile compounds in fresh roasted coffee are lost. Primarily, it will render the roasted ground coffee barely usable for espresso extraction. Other brew methods are less sensitive to oxidation.
Whilst these figures and stats might appear extreme, there's a reason why skilled and experienced coffee enthusiasts, baristas and well trained coffee professionals implement similar routine and rituals - only grind fresh roasted whole bean coffees and then use it immediately, never store the ground coffee.
Good espresso preparation technique involves pre-purging a quantity of coffee on the grinder to remove retained grounds residing in most grinders.
So the important message we wish to get across today is please don't grind and store coffee for use later.
That ground coffee loses most of it's attractive and alluring aromatics within minutes of grinding and you may not be able to effect a proper seal afterwards.
Leave ground coffee long enough and you might indeed struggle to achieve a decent extraction on espresso equipment.
Espresso extraction is by far the most sensitive method of coffee brewing requiring the freshest ground coffee.
Other brew methods where contact time with the ground coffee is longer, e.g. plunger/French press, percolator, drip or filter, etc. are less reliant upon the freshest grind.
But like all things in coffee, there really is not substitute for freshness.
So the big question this raises is "why would anyone buy pre-ground coffee".
Well the answer is not entirely straight-forward.
Mostly, it's because people don't have a grinder, don't want to buy or grinder, or have no space for a grinder or think the mess, noise and commotion of using a grinder is not for them.
Unfortunately, many of these coffee drinkers have not experienced the upside of grinding moments before use. They are not aware of what they are missing.
If pre-ground coffee goes stale so quickly, even in sealed and unopened bags, what is the best advice?
Don't buy pre-ground coffee in bulk - no amount of special procedures in storage like freezing, etc. is going to save the ground coffee.
Buying pre-ground coffee in bulk is really a bad idea - sorry, but we are only trying to help.
Our advice is to purchase only enough for around 2 - 3 weeks at most.
Don't think in terms of months with pre-ground coffee because you will always end up disappointed.
As we always recommend to customers whole beans are best......you are in fact buying a high-quality product, from the raw coffee, storage, roasting, packaging, shipping, etc. everything we do is to ensure the product arrives to you in the absolute best possible state so it can be enjoying at it's peak.
- Pre-ground coffee goes stale very quickly, even inside of sealed, unopened packs.
- Once a pack of pre-ground coffee is opened, or exposed to fresh oxygen, it has less than 15 minutes of "life" remaining.
- Don't buy pre-ground coffee in bulk and expect the quality to remain consistent - it degrades very fast.
- Don't grind whole beans and store it for later use, the ground coffee will have oxidized.
- Espresso extraction is extremely sensitive to the freshness of the roasted coffee.
- Using pre-ground coffee for espresso machines is not recommended as the coffee will have oxidized.
- Espresso extraction works best when you grind the whole bean coffee moments before use.
- Coffee packaging will not keep coffee fresh - nothing retards the effects of staling and don't believe the marketing rubbish about nitrogen flushing........nobody does it!