Copyright © 2018 by To’ak Ecuador Cia. Ltda. All rights reserved. No part of this document may be reproduced or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without prior written permission of To’ak Ecuador Cia. Ltda.
4
Introduction
5
8
Aging Dark Chocolate
W
e started developing our chocolate aging program in the latter months of 2013, when the fruit of our 2014 harvest was still but a collection of flowers. These flowers were growing on cacao trees in a valley called Piedra de Plata, deep in the backcountry of coastal Ecuador. By the time the rains came at the dawn of the new year, the flowers had already begun developing into cacao fruit. This fruit was mostly harvested by April, and by May the beans were fermenting and drying. By the end of June 2014, our chocolate was produced.
When the fruit of our 2014 harvest was still but a collection of flowers‌
9
We used a small portion of this chocolate to produce 574 bars of our Rain Harvest 2014 edition. Another small portion was used in Napa Valley by Chef Christopher Kostow of the Restaurant at Meadowood, which at the time was one of only nine restaurants in the U.S. to have earned the distinction of three Michelin stars. The remainder of our 2014 chocolate production was held back for aging. From our research on wine aging, we hypothesized that the tannins and other polyphenols in our chocolate would gradually be subdued through oxidation over time. This, in theory, would allow secondary and tertiary flavors to rise up to the surface. But at the time it was all conjecture. Another matter was how to actually go about doing it. 10
Photo: Restaurant at Meadowood
11
O
ne element in our favor was our location. We are headquartered in the city of Quito, which sits in a valley high in the Andes Mountains. At an elevation of 2,600 meters (8,500 feet) above sea level, at 0° latitude, Quito is
blessed with consistently cool and dry weather. Even without any heating or cooling system, the indoor temperature hovers within the narrow range of 1620 °C (61-68 °F) with 45-55%
relative humidity, every hour of every day of the year. These conditions are optimal for chocolate storage—a gift from the equatorial mountains.
13
Of all the spirits that we paired To’ak with, Cognac in general was always the best partner.
Aging Dark Chocolate
T
he idea of aging our chocolate in a Cognac cask came about quite naturally. Of all the spirits that we paired our 2014 harvest with, Cognac generally proved to be an optimal partner; often their flavor notes prove to be delightful complements. In some cases, the progeny of the two flavors—spirit and chocolate— could rightfully be described as sublime.
15
T
hrough a connection with Wine Spectator, we were put in touch with Nicolas Palazzi. Wine Spectator had recently run a feature on Cognac that credited Palazzi with leading the “rise of artisanal brandy in the U.S.” Raised amidst vineyards in the province of Bordeaux and trained by an artisan distiller in the province of Cognac, Palazzi is the man to speak with if you’re on the hunt for rare and unique Cognac. As it
16
turned out, he was also the right man to find if you’re on the hunt for a fifty-year-old Cognac cask. The cask Nicolas sourced for us was made of French oak from the Limousine forest in France. The cask most recently contained an eau de vie that was distilled in the mid-1970s and emptied in 2013 for a limited edition bottling sold to private collectors. Palazzi estimated the age of the cask to be over fifty years.
Aging Dark Chocolate
17
18
N
ext, we imported a single malt Scotch whisky barrel from the Laphroaig distillery. This was a more adventurous choice. We found that some Scotch whiskies paired quite nicely with our chocolate, but success varied according to the style of the whisky. Laphroaig is a 200-year-old single malt distillery from the Scottish island of Islay. It is famous among whisky connoisseurs for being on the far edge of the peaty spectrum and is celebrated for its highly distinctive flavor. It became a favorite pairing partner for our 2015 harvest edition, and so we decided to formally marry the two.
Aging Dark Chocolate
19
B
ut we didn’t stop there. Even though the Cognac and Scotch barrels were empty, the remnant vapor from the respective spirits was so powerful that we knew it would impart a pronounced new aroma to the chocolate—so much so that in some sense the vapor from these spirits could rightfully be considered an additive. This is exactly what we wanted from our barrel-aged chocolate. But we also wanted the opportunity to test our aging hypothesis without the added variables of Cognac and Scotch whisky vapor. The true test, we believed, would be aging the chocolate in a more neutral environment,
20
such that oxygen and time would be the primary forces at work. That said, we didn’t want to entirely rule out the possibility of using storage material such as wood to subtly enhance the flavor of the aged chocolate. After all, oak wood has long been used to enhance the flavor of wine and whisky. Why not apply this principle to dark chocolate? We eventually decided on testing seven different storage vessels—glass, adobe, and five types of Ecuadorian wood. We surmised that glass would be the most neutral material and adobe would potentially impart subtle earthy tones.
Aging Dark Chocolate
21
F
or the wood containers, we chose five species native to Ecuador, each with a distinct aroma and varying intensity: 22
• Spanish Elm • Ecuadorian Cedar • Andean Alder • Olivo • Coastal Ecuadorian Mahogany
We also experimented with variations in chocolate form. The predominant form was the tempered one-gram “coin.� We’d also been aging Aging Dark Chocolate
chocolate in untempered twenty-kilogram blocks, untempered crushed powder, and wrapped bars. Now all we needed was time. 23
24
Aging Dark Chocolate
25
28
TheStory of Tannins In a sense, tannins and polyphenols are the protagonists of this story. They are chemical compounds that cacao trees and grape vines produce to protect their fruit during growth. Timber trees like oak and Andean alder also employ them to safeguard their wood. Some of these compounds protect against ultraviolet radiation or microbial infection. Others have evolved to taste bitter over the course of millennia to deter insects and other animals from prematurely eating the leaves, fruit, or seeds. These compounds, also called flavonoids, largely determine what we taste in a
The Chemistry of Flavor (The Story of Tannins)
wine or dark chocolate and how it feels in our mouth. Tannins in particular are famous for tasting bitter and astringent. They even go so far as to bind to proteins—including the protein in our saliva. Tannins are what produce that dry, mouthpuckering sensation in certain wines and dark chocolates. In excess, they are unpalatable. But a wine or dark chocolate that is totally absent of tannins will have a flabby mouthfeel. The optimal level of tannins is somewhere between those two extremes and provides structure and complexity to dark chocolate and wine alike.
29
T
he plot thickens when it comes to aging. Tannins are a natural preservative. Traditionally, people “tanned� their animal hides with tannins from oak wood, producing the durable and long-lasting material known as leather. The same preservative properties are what allow for long-term aging of dark chocolate and wine. Tannins are also one of the keys to how dark chocolate and wine age and why this process can improve quality. There are a few caveats. Not all wines improve with age, and the same should be assumed for dark chocolate. If the tannins are badly imbalanced to begin with, even aging will not solve the problem. But if a wine or dark chocolate is relatively well structured at the outset, gradual changes over time may enhance flavors. This is where things get complicated.
30
The Chemistry of Flavor (The Story of Tannins)
31
TheScience of Aging Before going any further, it should be said here that the science behind the aging of dark chocolate and wine is still not entirely understood. Wine aging has been the focus of comprehensive research in recent decades and much has been discovered, but even the world’s foremost enological experts admit that a great deal still remains a mystery. Many hypotheses have been tested, and several have been substantiated, but the sheer number of variables and the complexity of the process renders the venture resistant to absolute proclamations. And even where science can clearly explain certain chemical pro-cesses, 32
how those processes result in changes of flavor is even more difficult to pin down. If the science behind wine aging is still not fully out of the woods, the science behind chocolate aging is presently stuck in a cave. At the initiation of our aging experiment, we couldn’t find any scientific papers focused on the subject. Our best guide came from a 2011 entry by Mark Christian titled “Vintage Chocolate” in the C-Spot, a website for chocolate reviews in which elaborate flavor descriptions and precise scientific explanations intermingle with philosophical musings. Christian is also on the board of directors of the Heirloom Cacao Preservation Initiative.
The Chemistry of Flavor (The Science of Aging)
“Theoretical and anecdotal evidence suggest that allowing a bar to mature under climate-controlled settings softens flavor tags and rounds off the sharp spikes and edges, mellowing the overall profile. What else the aging process might do— whether bringing greater concentration or added hues to the flavor graph— currently remains speculative for aging chocolate.” Mark Christian (C-Spot)
33
C
hristian described a study by Dr. W. J. Hurst that found eighty-year-old cocoa powder and 116-year-old cacao beans to still have very high antioxidant activity and flavan-3-ol content.
34
Christian goes on to note, “From this it might be deduced that rancidity is probably minimal since cocoa butter should be buffered by cacao’s antioxidants. One measure for rancidity—peroxide values—also remains stable, experiencing very little oxidation.”
Christian then lays out the outlines for a chocolate aging experiment: “The study may also entertain controlledoxidation—i.e., careful exposure to the elements that could improve a chocolate’s flavor better than wrapping
it tight as a mummy. To cite cigars again, they react positively to oxidation… up to a point. It tends to mellow out tannins over time, breaking down astringency and bitterness, as well as meld flavors for more unified taste.”
This entry was all we had to go on. But it was enough to inspire action.
The Chemistry of Flavor (The Science of Aging)
35
F
urther information was provided by chocolate guru Clay Gordon, who has found that the acidity of cacao beans continues to evolve for a period of months—at the very least— following fermentation and drying. We wanted to know how acidity would evolve over a period of years, not only in raw cacao beans, but also in finished chocolate. The famed Nacional variety of cacao from Ecuador, from which To’ak chocolate is made, has a reputation for moderate-to-high levels of acidity. This acidity is part of the reason for the prized fruity notes of Ecuadorian cacao. But too much acidity can be a defect, hence the importance of moderating its influence. Gordon found that
36
acidity levels tend to drop over time, at least in the short run. We wanted to analyze this question in the context of our own harvests. Our questions were: How much does acidity drop, and over what time period? And where on this flavor curve is the optimal level of acidity?
Our questions were: How much does acidity drop, and over what time period? And where on this flavor curve is the optimal level of acidity?
The Chemistry of Flavor (The Science of Aging)
37
The Chemistry of Flavor (The Science of Chocolate)
TheScience of Chocolate At the point of harvest, cacao fruit is by some accounts the most antioxidant-rich food on earth. As many as 750 compounds assigned to seventeen distinct chemical classes have been identified in cacao, with a phenolic richness that rivals wine. This potent cocktail of compounds is merely the starting point for a long journey of chemical evolution that will shape the flavor of the chocolate that is ultimately from it. Fermentation of the raw cacao beans is the first serious round of chemical changes undergone during the production process. Yeasts, acetobacter, and lactobacter convert sugars into ethanol
and then into acetic acid, which breaks down the cell walls of the beans and allows enzymes to act upon the polypolyphenols, generally softening them. The next big flavor-producing stage is roasting, with Maillard reactions converting tannins into phlobaphenes, producing a host of aromatic chemicals— most notably aldehydes and pyrazines. Lastly, there is the conching process, in which chocolate is churned in its liquid state under conditions of moderate heat, expunging residual acetic acid and other volatile chemicals before the chocolate is tempered and molded into solid bars.
The Chemistry of Flavor (The Science of Chocolate)
39
T
he question is: once this process has been completed, what additional chemical processes continue to unfold over time? To find out, we contacted a wide range of wine-makers, master sommeliers, enologists, and even molecular scientists. We started out by asking which elements of wine aging would also apply to chocolate aging. As we gained more answers, our questions became more refined, and we began to focus on the chemical processes specific to chocolate aging. First off, we should define what we mean by “chocolate aging.” A bar of chocolate that was left in the back of the kitchen cupboard for a year or two—especially a cupboard subject to wide temperature swings—will be marked with white splotches. This is called “fat bloom,” a consequence for any chocolate that is stored in fluctuating temperatures for any period of time. The temperature variation causes the cacao fat to separate from the cacao solids and rise to the surface of the bar. If chocolate is stored in damp conditions, there is the additional problem of sugar bloom.
First off, we should define what we mean by “chocolate aging.” 40
The Chemistry of Flavor (The Science of Chocolate)
41
T
he chocolate we’re aging is stored in perpetually cool and dry conditions. Before the aged chocolate is finally produced and enjoyed, it is first retempered and newly formed into bars. Unless you can ensure optimal storage conditions over the long term and are equipped to properly retemper and mold bars, aging chocolate should not be attempted at home. But if the right conditions are met, what happens? As a wine ages, harsh-tasting polyphenols such as tannins gradually polymerize into different chemicals that taste less astringent and allow for a more pleasant mouthfeel. With the sharper notes subdued,
42
a host of more subtle flavor notes, which were previously overshadowed, can now be perceived and appreciated. The sensory experience offered by the wine has been transformed.
Unless you can ensure optimal storage conditions over the long term and are equipped to properly retemper and mold bars, aging chocolate should not be attempted at home.
I
n our flavor analyses of both our 2014 and 2015 vintages over time, we observed a similar process unfold. For the chocolates aged in the Cognac cask and Scotch barrel, the results were very much in line with
44
The Chemistry of Flavor (The Science of Chocolate)
what we expected: the aroma and flavor were delightfully infused with Cognac and Scotch, respectively. But the chocolates aged in glass, adobe, and wood also showed a subtle yet fascinating transformation.
45
46
E
ven in the case of the glass-aged chocolate, theoretically the most neutral of the storage vessels, we found that both astringency and acidity were softened. The fruit notes that initially presided on the palate had also shifted somewhat and the edges had been rounded— the rises rose more gradually but also fell more gradually. The tannins and spice of different wood storage vessels also imparted new flavors to our chocolate. The personality of the chocolate had matured; a new expression of chocolate had come of age. This is what we found with our palate. Now we wanted to learn the science behind what we were perceiving.
This is what we found with our palate. Now we wanted to learn the science behind what we were perceiving.
The Chemistry of Flavor (The Science of Chocolate)
47
In wine, the transformation of mouthfeel and flavor is attributed to various complex chemical processes, ranging from phenolic binding and esterification of acids to hydrolysis and oxidation. Do any of these processes also apply to chocolate? Despite their many similarities, wine and dark chocolate also have their differences. How might aging unfold with the latter? One of the people we spoke with was Dr. Andrew Waterhouse, a wine chemist and enology professor at the University of California, Davis. Dr. Waterhouse affirmed that chocolate has a high level of condensed tannins. One major 48
difference between wine and chocolate, he pointed out, is the state in which it is stored. Wine is a liquid matrix, so oxygen creates a reaction within a few days or weeks. As chocolate is stored in a solid state, he said that oxidation will occur but the process may be much slower. But how much slower, and what do those changes look like? One clue was provided by a 2009 study conducted by Dr. Mendel Friedman. He found that dry green tea leaves lost significant amounts of two key flavonoids (epigalloepicatechin gallate and epicatechin gallate), but a third key flavonoid (epicatechin) remained stable over time.
We discussed this finding with Dr. James Harbertson, associate professor of enology at Washington State University. He told us that epicatechin gallate behaves like a hydrolyzable tannin and can bind to protein, albeit in a limited way compared to condensed tannins. This would suggest that bitterness and astringency from that particular set of molecules should decrease over time. A question that remained, he said, is whether or not the initial concentration of epicatechin gallate is large enough to be a significant aspect of aging in chocolate. Another key chemical
difference between wine and dark chocolate is alcohol content. Ethanol is present in cacao during the fermentation process, but is converted to acetic acid, which is later expelled during drying. In wine, ethanol is responsible for the formation of acetaldehydes, which in turn promote the cross-linking of a key flavonoid called anthocyanin, which is also present in cacao. Crosslinking is a chemical reaction in which small molecules combine together to form larger molecules. In wine, this process has been found to decrease the perception of astringency over time. Might something like this also apply to dark chocolate?
Might something like this also apply to dark chocolate? The Chemistry of Flavor (The Road to Descovery)
49
T
his brought us to Dr. Benjamin Lewin, who is both a certified Master of Wine and a molecular scientist. Even without ethanol, Lewis pointed to the presence of cane sugar in our chocolate. The glucose and fructose within cane sugar could produce an aldehyde that could potentially cross-link flavonoids such as anthocyanin.
Graphic: Anthocyanin with sugar
50
One question was whether or not the aldehydes formed by sugar would be powerful enough to perform this action. What we learned over the course of our initial investigation only inspired more questions. To dig deeper into the science behind this process, the enology department at the University of Washington is currently analyzing a vertical sampling of our chocolate, from fresh to aged, as well as assessing changes over time. Our goal is to age each of our harvest
editions for up to twenty years, possibly even longer, so long as they continue to transform in a positive direction. In the meantime, we continue to taste each vintage every six months to measure its evolution. If and when we find it to be at a phase that is particularly interesting to the palate, we produce a very small edition and offer it to the public. We are now at three years for our 2014 vintage and two years for our 2015 vintage, and we are ready to share this culinary voyage with the public.
Our goal is to age our 2014 edition for up to twenty years. The Chemistry of Flavor (The Road to Descovery)
51
The barrel-aging process of whisky presented us with another field of insights. The epiphany came during a visit to the Buffalo Trace bourbon distillery in Kentucky—home of the whisky world’s most elusive spirit: Pappy Van Winkle. The air temperature outside of the barrel has profound impact on the flavor evolution of the spirit while it ages inside the oak barrel. As the ambient air temperature rises—for example, during a hot Kentucky summer at noon— the liquid expands and the pressure rises, such that that
56
whisky pushes deeper into the oak grains of the barrel. Then when the temperature cools at night—not to mention winter—the volume of the liquid contracts and pressure drops, such that the whisky is pulled back into the barrel. As the whisky is pushed deeper into the wood during spikes of heat, it is treated to greater interaction with extractable aroma compounds in the oak. Then as the liquid contracts back into the barrel, it pulls the flavor from the wood with it, which largely accounts for what we see and taste in whisky.
Wood & Barrel (Lessons from Whisky)
57
I
t is estimated that the barrel accounts for 60-70% of the aroma and flavor of a well-aged whisky. Hence the supreme importance of barrel selection and aging conditions for whisky. Chemical compounds within the wood play a key role. Lignin most notably imparts vanilla notes, and can also contribute floral and spicy aromas. Lactones lend a buttery, coconut character. Hemicellulose offers a gamut of extractable aroma compounds ranging from nutty and caramel to sweet and malt. Then there is the question of microclimate. The warehouses
58
of some distilleries rise as many as eight floors high. The barrels on the highest floors mature more quickly, where the ambient temperature is more variable and tends to reach the highest temperatures. The whisky aged on the ground floor matures the slowest, because temperature fluctuations are moderated by the relative cool of the ground. It is said that aging whisky for only four years in Kentucky, with its hot summers and cold winters, is comparable to aging whisky for ten years in Scotland, where the weather is consistently cool year-round.
Wood & Barrel (Lessons from Whisky)
59
60
Photo: Juan Carlos Bayas
Ecuadorian Wood This fascinating piece of information got us thinking. Owing to the climate extremes created by the Andes Mountains, in Ecuador we’re blessed with the unique opportunity to simulate the weather of both Kentucky and Scotland pretty much any day of the year. In the coastal province of Manabí, where we harvest, ferment, and dry our cacao, the weather is unabashedly tropical. In the daytime it often reaches 31 °C (88 °F), and at nighttime it drops down to a more comfortable 21 °C (70 °F)— which closely parallels the average summertime weather Wood & Barrel (Ecuadorian Wood)
in Kentucky. Meanwhile, up in the high mountains of Quito, where we make our chocolate, the average daily temperature range is 10-19 °C (50-66 °F), which roughly resembles Scotland during its warmer months, albeit with a lot more sun. For our Vintage 2015, we did an experiment. We put some of our 2015 harvest into two Ecuadorian cedar vessels. We stored the first Ecuadorian cedar vessel in Quito, alongside our Cognac and Scotch whisky barrels as well as our other wood vessels. Here the indoor temperature is always about 18 °C (66 °F), and so the chocolate remains in solid form. 61
62
T
hen we brought the other Ecuadorian cedar vessel down to our postharvest farm in Manabí. We even went so far as to store this vessel inside our solar cacao drying room, which resembles a greenhouse. During a sunny day, the temperature in the drying room typically exceeds 38 °C (100 °F), and drops down to 21 °C (70 °F) at night. When dark chocolate rises above 30 °C (86 °F), it melts into liquid. Then when it dips back below this threshold, it becomes solid. Our hypothesis was that the chocolate stored inside the Ecuadorian cedar vessel in our extremely hot solar drying room would liquefy and solidify on a daily basis. When in liquid Wood & Barrel (Ecuadorian Wood)
form, the chocolate would have greater contact with the extractable compounds of the wood the walls of the vessel, penetrating the wood. Then when the weather cooled and the chocolate solidified, it would include extractable compounds from the wood. This process would thus allow for a rapid and pronounced flavor evolution. Meanwhile, the chocolate stored inside the Ecuadorian cedar vessel in Quito would remain in solid form throughout. We hypothesized that it would still be imbued with the distinctive aroma of the cedar, but with much more subtle results. With our Ecuadorian Cedar Matured edition, we hereby share the delightful results [for release in autumn 2017]. 63
64
panel of flavor analysts and conducted a blind aroma test. Everyone unanimously agreed that the most flavorful of the wood-aged chocolates, at this particular juncture, was that which had been maturing in Andean alder.
O
ur Andean Alder Matured edition has a different genesis. For three years, our Vintage 2014 chocolate lived inside four different wood vessels. Two and a half years into the experiment, we sat down with our intimate Wood & Barrel (Ecuadorian Wood)
Andean alder (Alnus acuminata) grows wild in the mid elevations of the Andes Mountains. Alder wood has long been used for both medicinal and flavoring purposes. Like oak, it is rich with tannins and has traditionally been used to tan leather. With our chocolate, we found that Andean alder imparts a prominent aromatic note unlike any other we’ve experimented with—a charismatic flourish that works well with our 2014 harvest. 65
Harvest Notes
As with wine, the quality of a given harvest depends on the weather of a given year. This effect is even more pronounced in the valley of Piedra de Plata, where To’ak’s small group of fourteen cacao growers do not irrigate their cacao. Instead, they practice “dry farming,” as it is called in the wine world. Annual precipitation in Piedra de Plata can range from less than 800 mm during extremely dry years to over 2,000 mm in extremely wet years. In some years the rainy season may be long and drawn out, in other years it can be short and intense. Some years are heavily overcast, others are unusually sunny. The variables are infinite; no 66
two years are alike, and each divergent circumstance exerts its own influence on the flavor profile of our chocolate. The 2014 harvest was forced to make do with less sun and less rain than that of previous years, which contributed to a relatively more acidic cacao with more prominent tannins. To address this circumstance, we lengthened our fermentation time to six days, which did much to moderate the astringency. This was followed by a moderate roast and a relatively short conch of twelve hours. The result is a seductive chocolate with many layers of complexity, imbued with a delicate floral perfume—a fascinating vintage. Wood & Barrel (Harvest Notes)
67
68
B
elow average rainfall continued into the 2015 harvest, although both rainfall and sun exposure were greater in 2015 than in 2014. This weather yielded a moderate crop of cacao with a high concentration of sugar and a low incidence of disease and fungal attacks. It was considered an excellent year for cacao, which we believe is reflected in the chocolate. Our 2015 harvest had lower acidity and astringency compared to our 2014 harvest, leading to a balanced flavor profile
Wood & Barrel (Harvest Notes)
decorated with a procession of fruit and floral notes. This is a more accessible vintage. The recipe for our 2014 vintage was 81% cacao and 19% cane sugar. For our 2015 Rain Harvest Light vintage, the recipe was 73% cacao and 27% cane sugar. Both ingredients are organic and fair trade certified. No extra cacao butter or any other additive was used. For updated tasting notes and a list of recommended pairings, please visit our website at www.toakchocolate.com
69