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PC 6.05 Interview with Rachel Peterson

An Interview with Rachel Peterson from Hacienda la Esmeralda about Mechanical Drying.

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Rachel Peterson and her family operate the world famous Hacienda La Esmeralda in Boquete, Panama. It was in 2004 at the Peterson’s Jaramillo Farm that the incredible rediscovery of Panamanian Geisha occurred. The geisha variety from Hacienda La Esmeralda first competed and won in the Best of Panama in 2004, and continued to win for many years to come. The Petersons have led the way in promoting direct trade and hold their own online auctions each year where what many consider the world’s most delicious coffee is sold.


Barista Hustle: In the beginnings of the specialty coffee movement in the early 2000s, we sensed that drying machines had a bad reputation; baristas and micro roasters seemed to associate the use of this technology with huge scale production of commodity coffees. But since farms like Esmeralda started achieving such spectacular results with the use of drying machines, people’s attitudes seemed to have changed. Did you ever experience any negative reactions from customers about the use of Guardiolas at the farm and have you noticed a change in people’s attitudes? 

Rachel Peterson: In terms of the rotating dryers or Guardiolas, there was an original pushback, but the consistency in drying achieved by a Guardiola has no parallel. If it rains, if it’s overcast, if it’s too sunny … it still dries slowly and steadily to the humidity percentage desired.


B.H. Has there been any changes in the way you use these machines since the early days or has best-practice with the use of Guardiolas been the same for a long time?  

R.P. The only real change that I’ve seen take place is that we now have many and smaller guardiolas, since the one drawback about using a Guardiola is that you need to have a certain amount of coffee to use it. The last couple of years I have seen the old style larger guardiola’s subdivided into two, or four different drying areas, and I have also seen a lot of smaller guardiolas being used. They have also become more energy efficient.


B.H. Do some of your micro lots at Esmeralda start out on raised beds and then are finished up in the Guardiolas? If so, how many days does a typical Esmeralda natural spend on raised beds before heading into the Guardiolas? (Or is there no simple recipe here? If not, can you tell us a little about your decision making?)

R.P. Many of our micro lots are too small to dry in a Guardiola so we either dry them on the patio or on a raised bed. Normally we will let them finish drying the same way that they started, unless we have a change in weather.

The more affordable the coffee, the more likely that it was harvested in larger quantities and was fully processed in the Guardiolas. In the case of Esmeralda Special and Esmeralda Private Collection there will be a variety of different drying methods used, such as regular patio, regular raised bed, slow shade dried raised bed or Guardiola. It also depends to a very large amount on the availability of drying areas that we have on the day that the coffee is harvested.

As an example, over the last couple of years we have increased our production of naturals about 40%. Naturals take a longer time to dry, and if we have a lot on the patio and the raised beds, we might need to decide to process a coffee as a washed and the next day put it into the predryer and then the rotating dryer immediately.

As a precise example of the use of these guardiolas, twice this year we had very large lots of a good coffee called Mario that we put out to dry on the patio. The weather turned (it was too early to put it in the Guardiola, since the cherry was still juicy) so we picked up the coffee, depulped it and washed it, and put it to dry in the Guardiola. We sold it this year as a washed coffee, with strong fruit character, and an almost natural character to it. It was very popular, and would have been impossible without the Guardiolas.


B.H. When it comes to producing your best lots at Hacienda la Esmeralda, is the combination of raised beds and Guardiolas always the secret to your success, or is it possible to achieve your best quality with 100%-raised bed drying or 100%-machine drying too? 

R.P. We do both every year, and normally we will find outstanding lots with any of these drying methods. Since many of our best lots are experimental, the quantity is too small to put into a Guardiola, so it’s not really a fair comparison.

In terms of the drying itself, we have done cuppings many times with split lots (one half in Guardiola, one half on a raised bed) and we have never had a consistent result. Roughly half of the time the rotating dryer is better and half the time raised beds.


B.H. We understand it takes longer to dry naturals than it does to dry washed coffees. Is drying coffee at all like roasting coffee? I.e. Is there such a thing as ‘profiling’ when it comes to machine drying coffee or is it more simple than that?

R.P. It does take longer to dry natural coffees, because of course you are drying the cherry along with the bean. And depending on the drying method that we use (in addition to additional processes such as anaerobic fermentation and spraying yeast) the final taste will depend very much on the way the coffee was dried. For a very clean natural, you dry it on the sunny patio for three days and then in the rotating drier for 80 hours (about 8 hours a day). For anything fruitier, or more winey, or more funky, you must extend the drying time all the way to keeping the fruit completely shaded while drying for a more musty whisky type flavor profile.