Coffee grinding just before you prepare your brew is the best way to give the coffee a chance to give you its best. Of course if it is already stale that is another story.
Freshness is the Essence
The shorter the time interval between grinding and brewing coffee, the fuller the aroma and flavour of the final product. Coffee in a whole bean offers some level of protection to prevent coffee going off (the unroasted bean can last around 1.5 years, the roasted bean four weeks – if kept in cupboard) and two months if frozen before the oils are exposed to the surface.
Coffee once ground, starts oxidizing within seconds, and starts losing aroma and flavour almost immediately. This means that if you are a coffee lover, the first step you need to take to start enjoying more flavour is to own a grinder.
Grinds that are going off become stale and bitter (sometimes perceived as strength). So purchasing pre ground coffee is a bit like purchasing a great Champagne (or Cap Classique 😉 for us South Africans) and asking them to take the cork out before you take it home.
In the blind tastings we have done, once a coffee has been ground as early as an hour before it it is brewed everyone noticed the difference, and the freshly ground and the one hour old coffee has never been linked
Yes But
What about all the specialist packaging methods, like pods, vacuum packed and sealed tin etc. I hear you ask. All these methods do is delay the process of the coffee going off, slightly but the coffee bean is still the most effective. The coffee bean is able to retain the flavour for two – four weeks if stored in a cupboard, and two months if placed in a freezer. Read more on the freshness page.
Type of Grinder
There are essentially three types of grind:
- chopping
- milling
- burr grinder
Of these the most effective method has been found to be burr grinders
If you are on a budget and use a plunger than a electronic blade chopper (sometimes incorrectly called a coffee grinder), will do. But the burr grinder is the best solution, with a conical burr grinder often considered best, however large burr grinders sometimes do a better job. Burr grinders, are able to grind the coffee relatively uniformly and do so without adding heat and thereby keeping the taste and aroma intact.
Coffee grinding – fineness of Grind
The general belief regarding fineness of grind is that the brewing method used and roasting method used are interlinked. Here are a few pointers:
- the lighter the roast, the more course the grind can be for you to enjoy a full flavoured or aroma coffee
- the more pressure that is applied during the brew the finer the grind can be
Although each person’s taste is different here some guidelines for common brewing methods, for our preferred roast level.
| Machine Type | Recommended Grind |
|---|---|
| Chemex/cupping | Very course (i.e. large granules visible) |
| Domestic filter machine or plunger (French press) | Course (i.e. medium-large granules visible) |
| Office filter machine, percolator, Hario V60, manual pour over | Course to medium. For manual pour over time is the guide too long coffee is to fine, too short coffee is too course |
| Stove top espresso | Medium |
| Vacuum brewer | Medium |
| Aeropress | Medium-fine |
| Super automatic coffee maker | Medium |
| Domestic espresso machine | Medium fine (no clumping)- determined by pour |
| Commercial / semi commercial espresso machine | Fine (no clumping) – determined by pour |
| Turkish brew | Very fine powder like |
