Coffee Quality Lifecycle Explained

Most people think a coffee roaster heats any type of green coffee beans until they are brown - like cooking meat in an oven, pan or BBQ, but there is a whole lot more science and skill involved.
 

When it comes to coffee, the world has many experts - from the local cafe barista, the internet forum blogger or the guy who tells all his friends he can only drink his home-roasted coffee beans because it's fresher and higher quality than anything else he can buy.

The reality is coffee is extremely complex.

At each stage in the lifecycle, from farmers tending to crops, processing the harvested cherries, transporting and storing green beans and then what the roaster does in his equipment and finally, the distribution and extraction (brewing) of the finished product for consumption.

At each stage, there are considerable risks and issues associated with the handling of coffee that can result in a reduction of the end-cup quality.

Generally speaking, the higher chances of poor cups are at the brewing and roasting stage.

Farming and Origin risks

Farmers are becoming more informed of improved practices that can yield higher prices for better quality raw green coffee beans.

The standard continues to rise with the growing market size and demand for specialty coffee.

We continue to see the market for lower-grade coffees contracting (usually supplied to providers servicing instant and supermarket-grade coffees).

Harvesting and processing coffee cherries play an important part in determining bean quality.

As with many agricultural products, coffee is subject to nature and all its variances as the coffee trees bloom from flowering into cherries that ripen.

Coffee is typically grown at high altitudes around the world.

However, the majority of the coffee cherries are usually harvested by hand, which can lead to various issues such as under-ripe, over-ripe, or pest-ravaged cherries being collected along with the good ones to "fill the sack".

In some areas, pickers are paid per sack, which means that the incentive for selecting and harvesting high-quality cherries may be less of a priority than simply filling the sack.

Grading and Processing

The grading process at Co-ops and processing stations needs improvement.

Co-Ops and processing plants still practice the skill of blending - taking excellent coffees and mixing them with average to meet grade requirements.

However, some farms are taking control of their processing by ensuring less blending and preserving the integrity of the harvested crop.

Processing is one area where the coffee quality can be either improved or destroyed.

Unfortunately, processing techniques vary from region to region, and the discipline and controls are better in some countries than others.

For example - Costa Rican and some Central American farmers exercise absolute control over the processing methods - protecting the beans from the risk of adverse weather and avoiding ferment taints from poorly prepared coffees.

Sumatra is an origin that uses a unique process called wet-hulling.

This process creates coffees of exceptional body and low acid but runs the risk of ferment taints such as mold developing that can destroy an otherwise fine coffee bean.

Processing methods such as unwashed, sundried, and triple-picked can develop intensely sweet coffee beans.

Ethiopia is famous for the best unwashed, dry processed coffee beans.

Transport and Storage

Once the beans have been processed, the handling of the coffee needs to be carefully managed.

Storage facilities at origin can be very basic and rudimentary - sometimes just a simple tin shed.

Packing the beans into grain-pro bags or vacuum-sealed foil can be expensive at the origin.

Still, the benefits of having coffee beans stored in a package that reduces the impact of fumes and other toxins from being absorbed by the green beans lead to a higher quality bean.

We purchase as many coffees as we can in grain-pro bags.

We want to make it a universal policy only to purchase grain-pro bagged greens, but the reality today is that some origins and farms simply cannot provide this method.

As of April 2012, approx. 35-40% of the coffees we purchase are shipped in grainpro, and we see this ratio increasing as the demand forces the suppliers to provide this at the origin.

Sometimes, coffee is stuck in export sheds for months, awaiting buyer's contracts, shipping vessels or port availability.

For example, some of our favourite coffee beans from PNG are from the Mount Hagan area.

There is only one road from the highlands down to the distribution highway, which gets washed out from heavy rains every year.

Other countries like Uganda are landlocked, which means that they need to have their coffee transported through another country to load it onto a ship.

Containers get extremely hot, and coffee sweats inside.

This results in a decrease in the quality of the beans by the time they reach the importers and roasters.

Green Bean selection and Roasting

Roasters select green beans based on many personal choices.

Sometimes, companies need to balance budgets while maintaining marketing, equipment, and contract selling prices.

Other times, it can be a desired taste, e.g. trying to compensate for a change in a new crop coffee that brings a blend back in line with a required specification.

Ultimately, coffee brand and their roasters make these choices.

At any time, there may be more than 400 different coffee beans available to Australian roasters from the major brokers.

Once a bean has been selected, whether it is roasted individually or mixed into a blend, the roaster needs to understand the capability of the bean fully.

Some beans respond better at lighter roast levels, whilst other coffee beans will work better at darker levels.

If a blend has many different beans, it is important to ensure the selected bean works well with the others.

Not all beans can be blended successfully together - there are acid, fruit, etc. considerations.

We have blended beans in the past only to find out the hard way - they clash.

When it comes to roasting, every roaster thinks he is skilled and special.

There is such a broad variation in the quality of roasting equipment to the extent that the Australian market has a lot of small roasting companies employing cheap roasting equipment that generates inconsistent results.

It is a controversial statement to declare, but it's honest.

We started 20 years ago on a cheap Turkish roaster, and whilst some of the batches it produced were great, there were many so-so and some that were downright horrendous - we sold it after a few months.

Some Australian roasters using old or low-cost equipment also believe that plugging in a cheap digital multimeter and logging the roast progress (monitor) on a laptop is called profiling.

Nope, this is just watching and recording the action; it does nothing to compensate or target consistency.

Profiling controls the heat (energy source), airflow and other parameters to ensure the required roast cycle follows a pre-defined path.

When sophisticated roasting equipment is used by skilled roasters with quality beans, the results are predictable and superb.

We roast around 150+ batches a week, and the deviation is less than a few seconds between each batch.

So close is this tolerance it comes down to ambient conditions.

More importantly, we constantly cup the control samples - looking for defects or improvement opportunities.

A common story we hear from customers calling our business is "We used to buy brand X, but lately, the coffee is not good, and we don't enjoy it".

The answer to this situation is likely one of two possibilities - Brand X are buying green coffees that are inferior, or the roaster (and blender) has not been able to create a roast profile or blend that develops the best from their beans.

Consistency is important in coffee.

The largest variation we see in our coffees is in the Single Origins.

As we are dealing with just one bean, it is subject to some minor deviations from bag to bag - particularly the dry-processed coffees such as Ethiopians that have that "wild" character.

Brewing and Extraction

It's been said many times before on the internet, but we have to say it again. 

All the work of the farmer, the processor, the transporter, the roaster, the distribution, etc., can all come undone if the coffee is not brewed or extracted correctly. 

Under and over-extraction are common issues affecting the flavour of coffee. 
Incorrect grind, dose and exposure to heat and pressure can cause taints.

Unfortunately, the consumer drinking the cup of coffee blames the coffee brand. 

The reality is that great beans, perfectly prepared, will be destroyed in the hands of the unskilled barista.

Coffee is an oil that requires a precise balance of heat, pressure and time to extract.

If these variables are not correct, regardless of the brew or extraction method, then a less-than-ideal cup of coffee will be produced.