Roast Approach: Costa Rica Hacienda Sonora SL28/SL34 Natural

Today's coffee that we are going to approach is a fresh crop (2025) from Hacienda Sonora in Costa Rica.  This coffee is a natural processed mixture of the SL28 and SL34 varieties.  

Arrival QC & Coffee Details

• Harvest date: March 2025

• Arrival date: August 2025

• Moisture content: 11.00%

• Density: 1.17 g/ml

• Altitude: 1300 m.a.s.l.

• Cup score: 86.25

Fragrance and aroma of blueberry and coconut with notes of black cherry, grape and dark fruits. Aftertaste of black tea, dark chocolate and spices with a bright malic acidity. Heavy body with a really nice “full” mouthfeel. The overall profile feels very Kenya-like.

The Coffee:

This coffee was grown in the Central Valley region of Costa Rica at an elevation of around 1300 m.a.s.l.  This coffee is a mixture of the SL28 and SL34 varieties.  These varieties were developed in the 1930’s by Scott Labrotories (thus the “SL”) for cultivation in Kenya.  TheSL28 variety andSL34 variety were developed from Bourbon varieties and designed to be drought resistant while providing complex acidity and a heavy body.  

This particular lot of coffee is natural processed.  The coffee is slowly dried over a period of 12 days, with the seed remaining in the fruit.  Hacienda Sonora grows more than 20 different varieties on their farm.  

 The Roaster:

For these roasts, I'll be using a Proaster 1.5 kilo drum roaster hooked up to natural gas.  Batch size is 400g, approximately 35% of roaster capacity.  I've used a small batch size on this roaster to get closer to mimicking the gas power that you might find on a larger production roaster.  It must always be mentioned that each roaster is different.  The type of probe, placement of probe, and batch size will all influence the way in which bean probe temperatures are registered in a roaster.  With that said, don't read too much into the exact temperatures, but look more closely at the theory behind the approach, time spent in different development periods, and rate of rise to get a better idea of how to translate this profile over to your own machine.  

The Goal:

The goal in roasting this coffee was to bring forward some of the “Kenyan-like” qualities that we really enjoyed on the cupping table.  I was looking for a big body, deep fruit sweetness and a complex acidity.  After roasting a few rounds of the Victoria 14 variety natural lot, also from Hacienda Sonora, I was on guard for possible irregularities with the timing of first crack as well as rapid changes in my rate of rise once hitting exothermic energy reactions.  I wanted a roast that was able to mitigate the rate of rise crash/take off that I knew could potentially leave my coffee unbalanced.

If you would like to learn more about my four phase approach to roast profiling, check out my “Roast Approach: Roast Strategy” blog.

The Approach:

This coffee is dense, but also requires a fair amount of care due to the natural processing on the seed.  For this reason, I started the roast at a moderate charge temperature of 390 degrees and then gave a 50% gas application through the early stages of drying, increasing gas application at around 250 degrees.  My goal here is to ensure begin building energy in the seed so that there is ample available energy as the seed enters in to Maillard at around 305 degrees, in order to serve as a catalyst for the chemical reactions.  

Throughout the roast, I use a gradual increase in air flow, with full air flow before the coffee enters in to first crack.  I do this to help bring clarity to the final cup.  In my experience, too much air flow at the beginning of the roast can make it difficult to build the heat energy in the bean, while also accelerating the evaporation of moisture from the outside.  Too little air flow can mean that the beans are "soaking" in the gases that escape the coffee seed during the later phases of the roast.  I find that having air movement in the latter parts of the roast provide clarity in the cup.

Knowing that this coffee has a high acidity and propensity for heavy body, I wanted to ensure that the acidity was complex but balanced and the body was accentuated.  For this goal, I would need to stretch out the caramelization phase.  Stretching out the caramelization phase will tone down some of the acidity, as the acids are being broken down and utilized for the production of mellanoidins, which account for the body and mouthfeel of the coffee.  I didn't want to stretch the caramelization out too long, as I still desired for the coffee to have a lively and complex acidity.  At 370 degrees I pulled the gas application back to 50% and increased my airflow.  If I was looking to mute the acidity more in the coffee, I would look at pulling my gas application back to 50% earlier, perhaps around 340 degrees.  

The coffee finished with first crack happening around 388 (fairly late for this roasting machine) and a gradual step down in gas application.  This coffee is prone to having significant momentum out of first crack.  Even cutting the gas completely at 390 degrees provided enough energy to push the coffee all the way to the end, at 403 degrees.  

The Cup:

On the cupping table, this coffee had an aroma of blackberry and cantaloupe melon.  The body of the coffee was thick and syrupy with flavors of mango nectar.  The coffee had a complex acidity that was both lactic and malic.  Flavor notes of concord grape, red currant and melon filled the cup.  

The Takeaway:

I found this coffee to roast very similar to other Kenyan coffees.  It did well with heat and had beautiful acidity in the final cup.  It is important to recognize the significant amount of exothermic energy that this coffee has after first crack.  If you are not planning for it by 370 degrees, you have already lost control of the coffee.  I think this coffee would do fantastic on drip or pour over.  For espresso extraction, I'd recommend stretching the caramelization to mute out the acidity and emphasize the already incredible body.

Happy Roasting!