Forum

I spent the first few months of this year farming in Kona. I was recently considering everything I did not get out of the trip; all my unanswered questions. I could list about one million of them, but the ones that stick out relate to the significance of terroir in the development of the characteristics of the bean. I have broken it down to the basics:

Prior to brew method, and prior to roasting, and given that defects and problems in processing and handling are held to a minimum, why are any two green coffees different?

My understanding is that there are three variables: Terroir, Varietal, and Processing, where terroir is the geographic location and environmental conditions, varietal is the genetic makeup of the plant (bourbon vs caturra vs geisha etc), and processing is the method of fruit removal, fermentation, and drying that happens between harvest and green, ready to roast coffee.

Let’s say we have two coffee trees. Given the three variables listed above, the following situations are possible:

                TERROIR                     VARIETAL                    PROCESSING

0                   =                               =                                 =

1                   =                               =                                 ≠

2                   =                               ≠                                 =

3                   ≠                               =                                 =

4                   =                               ≠                                 ≠

5                   ≠                               =                                 ≠

6                   ≠                               ≠                                 =

7                   ≠                               ≠                                 ≠

Let’s consider 0 to be our baseline, where the farm, the varietal, and the processing method are all the same for our two plants. We are assuming that there would be no difference in the green coffee produced by these two plants. Variations 1-7 represent the possible different combinations of variables for our two plants. For example, in variation 1, the two plants grow on the same farm, they are the same varietal, but they are processed differently. In this case, the difference between the two resulting green coffees would be attributed to the different processing methods.

My questions are:          

1. In variation 2, our two trees are different varietals on the same farm, and they undergo the same processing. How does the difference in varietal manifest in the cup? How significant is this difference?
2. Similar to question a., in variation 5 our two trees are the same varietal but are in different regions and are undergoing different processing methods. If the varietal is the only thing that is the same, how does that manifest in the cup? Is the varietal a strong enough characteristic to be recognizable among the powerful influences imparted by terroir and process? Are there other ways in which the differences in varietal manifest?
3. Variations 3 and 4 are the crux of my ponderings. In variation 3, the terroir is the only source of difference between the two plants, and in variation 4, the terroir is the only source of similarity between the two plants. It might be obvious that two plants of the same varietal, processed in the same way, from two different geographic regions are going to be different. But two plants on the same farm that are different varietals and are processed differently have only their terroir in common, and can we discern that in the cup?

I recognize that this model is an oversimplification, but my questions remain. I also recognize that bX is not primarily a farmers’ forum, but I value everyone’s input on this site and I think these are questions that we would all benefit from asking and discussing. Thanks!