TRIP: Hawaii 2012 Day 6.5 Coffee Tour

Ok the Coffee tour and roasting class was so awesome and informative I had to break it out into it's own post. We learned so much about the coffee plant, the process of arriving at a bean and finally roasting, grading and what makes a good cup of coffee. There's a lot of pictures so this will be a long post but hopefully informative. Also note that all of this information is based on Kona coffee specific to this farm, why? At Mountain Thunder they farm at higher altitude, by hand, and conform to organic farming practices. I'll try to call out the info that's specific to this farm but since I've not been to another coffee plantation to compare this information I can't be sure what's specific to Mountain Thunder and practices are different at a commercial producer that's trying to control environmental conditions to produce the highest yield all at one time.

Ok it all starts here with the coffee plant and the coffee flower which is part of the gardinia family. The coffee plant only flowers when it has sufficient water to support a flowering. There is a specific season for coffee but it spans something like six months.

So what you'll have is flowers that open up after rain spells. Then what will happen is what you see pictured above, ripe red berries and green young berries. Some beans growing from early rains producing flowers and some growing later from later rain spells and subsequent flowers. So the farmers here have to go thru each plant and pick out ripe berry and go back to the plant later to harvest beans throughout the season. If they don't they risk mature berries falling and creating more coffee plants that compete with the mature plants for nutrition and water. Commercial plantations water at specific intervals to space out berry production so they can be certain to shake out all the berries on a tree and know they are all ripe. It removes some of the random factor on flowering of the plant.

Here's a macro on a ripe bean from my new olio clip for my iphone. (it does fisheye, macro and wide angle) I like the new toy.

It's not that easy waiting for the coffee to grow. The plants need fertilizer and you can cheap out with commercial stuff that wears out the plant and soil or go natural (they use donkey poo and remanent coffee cherry here). Then you have weeds to contend with. Thankfully geese like to eat this invasive species (and hence why they keep geese here). The weeds are a vine like plant that wrap around the coffee plant and sprout leaves making them hard to remove once they take hold.

Once upon a time they did pickings in 100 lb bags and a good picker could get 400 lbs per day. This is still true but technology has made it easier to transport beans on larger pallets and bags. All beans from Mountain Thunder are hand picked still because of the multi stage beans maturity that I described above.

Ok so once you pick the berries you have to separate the outer fruit from the seed (the outer fruit is called the cherry). The inner seed is usually two coffee beans with the flat faces facing each other on the rare event you have a single bean which is called a peaberry. Apparently at higher elevation there's a slower growth rate on the coffee which increases the chance of producing a peaberry. A peaberry is a desired result because the plant is devoting all of the nutrients into one bean instead of two. I drew some arrows if you click in to describe some various bean states.

The berries are sucked up into a giant machine, the berries are separated from the cherry outer fruit and then the green beans are sun baked fermented to dry up 20% of their moisture. From a 7 lb yield  6 lbs are the cherry fruitso you are left with 1 lb of bean. Once sun baked you lose another 20% of water weight then you hull the paper husks and lose another 20% weight.

The beans are then sorted. Our guide holds up a sample sifter. Kona coffee is sorted into several categories based on screen size, but even post the screen size there is a percentage of "damaged" beans and bad beans are judged by color and weight.

After being sorted the beans are shaken for weight, heavier beans get sorted upwards on this shaking machine crappy beans end up at the bottom. What we learned is that the "bad" beans are then sorted out and then roasted and sent out for the "blended" coffees. The coveted "good beans" are then used for their "reserve" and "premium" labels they sell on site.

Once the light beans go out then the beans sorted for color. A computer decides which beans are too light and need to be discarded and dark enough. Again, all this is done so that the a premium kona coffee can conform to less than 1% "damaged" bean.

Then after the sorting you begin the roasting process. The green beans go into a roasting machine where you control the external drum's heat with fire and internal drum heat with hot air. When you hit the right temp you drop the beans and start cooling. When you dump  depends on the roast you want to achieve. Experts go with a light roast because it tells you how well the bean was grown, the soil, and how well the roasting procedure went. At light roast all the oils are still inside the bean. The beans are dumped after "first crack" basically the popcorn sound of water being expelled from the bean. Medium roast happens before all the oils go to the external of the bean which happens at the start of "second crack" where the oils begin to expel to the surface of the bean. At dark roast all of the oils are expelled out of the bean (about 20 degrees past second crack), you also get some of the "burning" roasted flavor that dark roast is known for. This roasted flavor is used by commercial roasters to cover up for bad/damaged beans. Kona producers tend to frown on dark roasts and all premium labels are roasted to medium.  So lesson learned go with medium if you want to taste the quality of coffee bean.

So what better way to end the tour than to go and roast our own beans. Thank you Tomoko for being our guide. Here's a picture of our scaled down machine.

First pour out the green beans into the hopper, we were given fancy and extra fancy beans (top grade)

Then we turn up the flame control on the outer drum.

And we have the hot air switch.

Drop the green beans into the rotating drum.

green beans in the roaster. No color change yet.

Heat goes to 250 so we hit the air lever to 50/50 air.

We start to hit first crack at 350-375. It sounds like popcorn. This is where the green beans release water  from the bean. The beans have a brown exterior but the inner "seam" is still white/green. This is also when we hit the air into 100% mode.

We start to hit second crack around 400-425 degree and the inner "seam" goes brown. This is medium roast. The oil just now "starts" to pop if we let it go then all the oil goes to the surface. We don't want that we want the oil to be in the bean. At dark roast the bean also tends to spoil faster since the oil is exposed.

Drop the beans and they start to cool off.

You measure and the beans and bag them.

Then you take the bag to the sealer which shoot nitrogen into the bag to preserve the life of the bean by removing the oxygen. Then you heat seal the whole thing. The bag contains a one way valve to allow for the bean to out gas (but not suck in any more air). Out gassing happens over the next three days.

There you have it the full lifecycle of coffee making.


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