Selecting of defected coffee beans?

Why should we select defects from green or roasted coffee beans?
Good question!

Yesterday I had a short visit from Thomas, a coffee farmer in Peru, (Tropical Mountains) at our roastery on Spitalgasse. He arrived in the moment that I was selecting defects from a batch of freshly roasted coffee beans. He looked surprised and told me, that no roaster is selecting defects by hand like I was.

Selecting our Rocko Mountain by hand in the roastery

Yes, he’s right – maybe we are the only “crazy people”, selecting every single coffee bean by hand before we pack the beans. This makes the roasting process longer and even more exhausting than it already is without this extra work. Some roasters only do this kind of selection by hand for competition coffees, we on the other hand are selecting every coffee for every customer.

Evelyn selecting coffee beans in Yirga Cheffe, Ethiopia

But are we really crazy, selecting every single defected bean?
After a long roasting day and after taking thousands of “bad” beans out of the cooling tray or (in case of bad sorted green beans) on our selection table, I’m always asking myself the same question, And the answer is always the same: If you want the best taste in your cup, I have to do it!!!

Now I will tell you why it is so important to bring out the defects. On our journeys to the origin countries over the last years we found that every country, region or single farm has it’s own quality managment in case of sorting and selecting. It starts with the quality of picking the beans and ends with the setting of the sorting machines in the dry mills or factories. Every single step influences the quality (and the flavor) of the coffee and also effects the price of the green beans.

Once the coffee is in our roastery we have to handle the quality of the beans and therefore we do cuppings and find the best roasting profile for every bean. But, you can not handle defected beans. A bad taste gets even worse by roasting. Perhaps you can cover the visible defects by roasting darker, as most of the industry roasters do. They hide away most of the defects by using higher final temperatures and all the beans end up with more or less the same colour and taste the same >> burnt.
But not only industrial even specialty coffee beans do have a varying amount of defected beans in the bags and we don’t want to “burn” our coffees only to hide away the defects! So we decided to sort out the defects and therefore did several cuppings of bad beans. We cupped broken and split beans, unripe harvested beans (quakers) and other damage caused by insects and found out, every defect has it’s own taste, that is it’s own bad taste. Sometimes harsh and bitter, sometimes astringent and sour and sometimes everything negative combined. You’ll find some flavours of wood, paper or cardboard, leather, grass, mold or an unclean, grubby taste.
So we did blind flavor tests with seperated and mixed defects and compared them with good tasting beans. The results were impressive and shocking. The influence of defected beans on good ones was much higher than expected (statistically verified) and affects the flavour of coffee in a massive way. Especially the aftertaste of well selected coffee is tremondously better and clean.

You can do a simple test on your own!
Open any bag of coffee (as I told you, even the best specialty coffee beans have defects!) and pour the contents on a table. If possible put it on a dark surface and use a good light for selecting. Find some defected beans: Start with the lightest beans and go on to some broken or deformed beans,…
And now start to eat the lightest bean you find. Yes, just put it directly it in your mouth, start to chew on it and find the taste
– after 3-5 seconds,
– after 30 seconds and
– after 1 minute.

Take a sip of water and go on with a broken or deformed bean. I recommend not tasting more than three bad beans in a row.

At the end find a good looking bean and
And now, you know, why we are selecting our beans by hand.

Have fun with the experiment and please write to me about your experience:

Werner Savernik
Head roaster at CoffeePirates Vienna

Selecting of green coffee beans by hand – Yirga Cheffe, Ethiopia

2 thoughts on “Selecting of defected coffee beans?

  1. Would never had thought about bad beans, good read

  2. Good article, I have a French Press, it does take a long time to get a copy of this coffee machine, but
    I really like the way it was made to produce a cup of
    delicious coffee.


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