By Michael Laiskonis — Creative Director

Last month, the ICE Chocolate Lab launched Roots of Cacao, its first day-long symposium dedicated to all things chocolate. Through a series of talks, demonstrations, tastings and panel discussions, the program gathered more than a dozen chocolate makers, pastry chefs, industry insiders and historians to share their expertise with a packed room of nearly 100 attendees. Weeks later, I feel I am still soaking in all of the knowledge and insight shared in each intensive session, but a few thoughts still remain top of mind — ideas that I hope to address further at our next symposium.

Leading the technical side of the day’s conversation with his talk, “How Chocolate Gets Its Taste,” Clay Gordon, publisher of, broadly laid out the basic processing steps of chocolate from raw bean to finished bar, with a special focus on the complex building blocks of its flavor. Gordon proposed that over 750 individual chemical compounds contribute to chocolate’s typical flavor, reinforcing the notion that no single compound is responsible for chocolate’s complexity. It is thus the sum of many parts that gives each chocolate its character. Citing a study where researchers attempted to identify these individual components and theoretically reconstruct chocolate flavor, some surprising discoveries were made — the same compounds responsible for the aroma of peaches, cooked cabbage, cucumbers and even human sweat are all part of the mysterious stew that is chocolate. While the chocolate maker certainly brings much to the table, the development of these notes begins before the beans ever reach the factory. Genetics and post-harvest processes contribute significantly, and Gordon suggested that the microbiology responsible for fermentation may be the key driver of the terroir, or sense of place, that makes each growing origin unique. As a chocolate maker and educator, I’m inspired to better understand fermentation and its direct impact on flavor.

Our panel on sourcing and sustainability featured a wide range of perspectives, from manufacturing and supply chain to policy. Expertly moderated by Harvard lecturer Carla D. Martin, the discussion focused on the ethical, economic and environmental questions facing the industry. To put those issues in context, it is important to remember that the vast majority of cacao beans are produced by small farms typically only a few acres in size, and these farmers at the bottom of the supply chain see the smallest share in the price of a finished chocolate bar. One solution to this problem being pursued by panelist Tim McCollum, founder of Madécasse, is to significantly shorten that supply chain by working directly with farmers and building manufacturing facilities at the origin — Madagascar. Paying premiums for higher quality beans and creating a finished product of higher value at the source benefits not only the farmer but the greater local economy as well. From Mexico, the “cradle” of ancient cacao cultivation, ICE alum Jose Lopez Ganem shared his experience working on projects that seek to promote Mexican cacao by isolating the precise genetics and flavor profiles these heirloom beans offer; preserving and promoting these aspects of quality may reinvigorate farming in the region while also providing makers with unique high-quality beans. It proved extremely insightful to have World Cocoa Foundation president Rick Scobey join our discussion, as someone who navigates the world of so-called “big chocolate,” which relies heavily on cacao supplied by West Africa. Though craft chocolate makers typically ignore the “bulk” or “commodity” beans being grown, the sustainability issues on the table affect hundreds of thousands of farmers in countries like Ivory Coast and Ghana, who collectively produce nearly 75% of the world’s supply. The voice of the actual farmer is often missing from these discussions, and I’m already thinking of ways to include that perspective in next year’s symposium.

In between the demonstrations and panel discussions, guests were treated to several tastes from our chocolate maker presenters: Raaka, Dalloway, Cacao Prieto and Madécasse. Special guest Christopher Curtin, from Éclat near Philadelphia, shared his refined work, as did Marc Aumont from Kreuther Handcrafted Chocolate in NYC. Most surprising was a special juice tasting from Repurposed Pod — made from fresh cacao pulp pressed in Ecuador, the juice had a bright flavor redolent of lychee, passion fruit and banana. Later, the juice was also featured in a bourbon-based cocktail. Given our lack of a regular supply of fresh pods, I’m particularly excited about the potential of this juice as a teaching tool.

ICE's Chocolate Lab

A common thread that emerged throughout many of the presentations was the unsung role of women in chocolate. Historian and author Maricel Presilla highlighted the evolution of chocolate drinks through regional variations and innovations driven by women producers across Latin America — an idea echoed by Roger Rodriguez’s story of a sartorial hot chocolate lesson in the Dominican Republic that inspired his chocolate-making approach at Cacao Prieto. The reliance on women’s labor on smallholder farms in many parts of Madagascar and other cocoa growing regions was underscored by Tim McCollum, and our sustainability panel also addressed the rise of woman-run farmer cooperatives. I was excited to include up-and-coming Brooklyn chocolate makers Sara and Kelechi from Dalloway on our “craft” chocolate panel, who shared insights on their business and process. The subject of gender-driven marketing methods in chocolate advertising that tend to target women was raised during one of many open question-and-answer sessions. For our next symposium, we’re considering how we might grow the dialog on gender and other cultural issues — from producers to makers to consumers — in the world of chocolate.

The title, Roots of Cacao, evokes not only the rich cultural history of chocolate, but the entire chain of creation: the growers and origins responsible for supplying their precious harvests, as well as the makers and their processes. As much as chocolate reflects tradition, its evolution is also dependent upon innovation. While we ponder the complex path that chocolate has taken, we must also address the opportunities and obligations to foster a sustainable future. It has always been my goal to expand the reach of the chocolate making program in ICE’s Chocolate Lab beyond its four walls to include all of these conversations and the industry’s many facets. I’m grateful to all of our expert presenters and the diverse group of attendees for making the day a success — and I can’t wait to start organizing our next session!

Ready to study the pastry arts with Chef Michael? Click here for information on ICE’s Pastry & Baking Arts program.

By Michael Laiskonis — Creative Director

Long before we turned on the lights — and all of the machines — in the ICE Chocolate Lab, I began formulating a mission statement of sorts. In addition to exploring the fundamentals of chocolate-making and sharing that knowledge with our students, I also wanted to create a space that fostered a sense of community beyond our four walls. Over the years, we’ve opened up the lab to chocolate and pastry professionals of all stripes, not to mention scores of guests who just love tasting our efforts. As we’ve learned to make better chocolate, we’ve also added our own voice to conversations within the industry. This February, we’re taking advantage of our unique venue to promote the exchange of ideas with our inaugural chocolate symposium, Roots of Cacao.

Test Roasting Cocoa Bean Samples

Roasting Cocoa Bean Samples

I’m excited to announce that the ICE Chocolate Lab will host a one-day series of demonstrations, tastings and panel discussions on Sunday, February 4th. The title, Roots of Cacao, evokes not only the rich cultural history of chocolate, but also the growers and origins responsible for supplying their precious harvest. We can also trace the journey from cacao bean to finished chocolate bar by exploring the many flavors hidden within and the processes that unleash them. As much as chocolate reflects tradition, its evolution is also dependent upon innovation. While we ponder the complex path that chocolate has taken, we must also address the opportunities and obligations to foster a sustainable future.

To help us navigate these varied topics, we’ve enlisted a roster of expert presenters to share their knowledge — from industry insiders and academics, to pastry chefs and passionate connoisseurs. Featured presenters include Bill Yosses, founder of Perfect Pie Company and former White House pastry chef; Maricel Presilla, restaurateur and author of “The New Taste of Chocolate;” Clay Gordon, author of “Discover Chocolate;” and Roger Rodriguez, pastry chef and partner of Cacao Prieto (also an ICE alum!). Together, we’ll discuss how post-harvest processes at the origin lay the groundwork for the flavors in a finished chocolate bar, and how a pastry chef might harness those flavors in a finished dessert. We’ll explore the emerging culture of “craft” chocolate and how the industry is addressing sustainability on a larger scale. Attendees will taste the spectrum of chocolate’s expressions, from artful modern confections to the alluring drink our ancestors enjoyed. I, for one, am looking forward to all of the information and inspiration on tap. In the coming weeks I’ll share more about the presenters with further details on their sessions.


Chef Laiskonis’ Hazelnut Chocolates

Roots of Cacao symposium is open to the general public and the sessions have been designed to be accessible to all, no matter one’s knowledge of or experience with chocolate. I would recommend it to anyone who’s curious to learn more about the roots of our favorite confection. Plus, the more we understand where chocolate comes from and how it’s made, the more we appreciate those efforts. But a word of warning: as someone who has taken the deep dive myself, I often say that the more we learn about chocolate, the more we realize what we don’t know! Hope to see you there.

Space is limited — register today for Roots of Cacao.

 Want to take a deep dive into Pastry Arts? Learn more about ICE’s career training programs.

By Michael Laiskonis, Creative Director

When ICE moved into its current facility at Brookfield Place, staff and students were treated to new features like the Chocolate Lab – my home base – as well as our indoor hydroponic farm. This innovative space focuses on unique varieties of culinary plants grown for flavor, and their efforts benefit our students in the teaching kitchens as well as chefs and restaurants throughout the city. Every time I walk past the brightly lit farm, I can almost taste the dozens of flavors growing within and my imagination immediately starts to stir. This first in a series of posts traces some inspired ideas that emerge when we crossbreed these amazing raw materials with advanced pastry projects in the Chocolate Lab.

Anise hyssop parfait

The farm features several staple herbs — varieties of basils and mints, for example — plus new and exciting crops rotating into production on a weekly basis. During a recent tour and tasting of the hydroponic farm’s offerings, two items stood out: anise hyssop and purple oxalis. The former was an old friend, a sweet expression of licorice and mint. The latter, however, was something I was unfamiliar with. A relative of the sorrel family, the deep violet leaves of the oxalis resemble the flapping wings of a butterfly and provide an interesting tartness. More surprising was the flavor that came from its stem — a refreshing acidity that called to mind delicate young rhubarb stalks. To highlight these herbs, I began constructing flavors and textures in my mind. Sweet apricot, aromatic vanilla, honey, cream…with these building blocks in place, I picked my hyssop and oxalis and then headed into the lab.

Anise hyssop parfait

Sprig of Nepitella

As I assembled ingredients, the dessert’s architecture materialized. The anise hyssop would infuse an airy mousse, or parfait. The apricot would be lightly sweetened with honey and provide a fluid liquid center inside the parfait. A shiny glaze speckled with vanilla would enrobe the parfait, which would find its place atop a crunchy, buttery pastry base. Still enamored with the oxalis stems, I considered lightly candying them to preserve their slender form and to balance their flavor. The format of a petit gateau, an individual dessert often found in boutique pastry shops, offered the perfect format in which to condense these flavors and textures for maximum impact.

Stay tuned for more sweet collaborations with the hydroponic farm at ICE!

Anise Hyssop Parfait – Apricot, Honey, Vanilla and Purple Oxalis
Yield: Makes 16 individual desserts

Pâte Sucrée


120g unsalted butter, softened
2g salt
90g confectioner’s sugar
30g almond flour
50g whole egg
60g all-purpose flour (1)
175g all-purpose flour (2)


  • Combine and blend the butter, salt, confectioner’s sugar and almond flour in a food processor.
  • Add the whole egg and first measurement of flour (1); process just until incorporated.
  • Add the remaining flour (2); process just until incorporated – take care not to overmix. Wrap the dough and chill.
  • Chill or freeze. Allow a minimum of one hour resting period before use. Roll or sheet very thin, to a half sheet pan sized rectangle. Transfer to mesh silicone mat and par-bake sheets for five minutes at 150°C/300°F to set; cut 7cm (2 ¾ in.) discs and continue baking approximately five to ten minutes, or until golden brown.

Honey Apricot Coulant


0.5 sheet gelatin, hydrated
200g apricot puree
15g honey


  • Combine puree and honey in a saucepan. Bring just to a simmer.
  • Whisk in the gelatin. Drop into small silicone half-sphere molds. Freeze.

Anise Hyssop Parfait


200g whole milk
30g anise hyssop
60g egg yolks
75g sucrose
10g gelatin powder (225 bloom), hydrated in 40g water
400g heavy cream (36% fat), whipped


  • Place the milk and anise hyssop in a small saucepan and bring to a simmer over low heat, remove from heat, cover and allow the mixture to infuse for 20 minutes. Strain.
  • Prepare a crème anglaise with the infused milk, egg yolk and sucrose; cook to 84°C/183° Add the hydrated gelatin. Strain and cool to 25°C/77°F.
  • Fold the crème anglaise base into the whipped cream and deposit into silicone ‘stone’ molds. Allow to stand at room temperature for five to ten minutes, insert the frozen apricot coulant centers, top off the mold with additional mousse if necessary and continue to freeze completely.



9g gelatin powder (250 bloom)
45g water (1)
120g sucrose
75g water (2)
150g glucose syrup
160g white chocolate
100g condensed milk
Orange color, as needed (water-soluble, powder)
1 vanilla bean, split and scraped


  • Hydrate gelatin in the first measurement of water (1).
  • Combine the sucrose, second measurement of water (2) and glucose in a saucepan and cook to 103°C/217° remove from heat and add to the white chocolate and condensed milk.
  • Incorporate the gelatin, as well as desired color and scraped vanilla bean pulp, and emulsify.
  • Chill, utilize glaze at 30-32°C/86-88°F



White chocolate décor
Anise hyssop, leaves and flowers
Purple oxalis, leaves and candied stems


  • Place the frozen, unmolded parfaits onto a wire rack and glaze with the warmed glaçage. Briefly chill to set.
  • Transfer each glazed parfait to the baked sucrée discs and allow to temper. Finish with the white chocolate garnish, anise hyssop, purple oxalis and nepitella flowers.

Anise hyssop parfait

Want to explore the Chocolate Lab and hydroponic farm at ICE? Learn more about our Pastry & Baking Arts program.


Sometimes, a moment of inspiration can change the course of your career. Whether it’s an ah-ha! moment or a taste of something outstanding, it sets you on a new path of discovery. For Pastry Arts student Calvin Luk, his moment came during a visit to the York Cocoa House Chocolate Emporium in the U.K. The Hong Kong native had relocated to York to study archaeology, but one sip of the famed York Cocoa House hot chocolate and he knew his future lay in the art of chocolate making.

Soon after his visit, Calvin began working at the acclaimed York Cocoa House. When he realized he was ready to take his education to the next level, he chose the Pastry & Baking Arts program at ICE. Asked why he chose ICE, Calvin explained that he was, unsurprisingly, drawn to ICE’s bean-to-bar Chocolate Lab, led by James Beard Award-winning pasty chef Michael Laiskonis. Once he arrived, Calvin knew he had made the right choice: “I had been studying chocolate-making for some time,” he says. “But it wasn’t until I met Chef Michael Laiskonis that I realized there’s so much more to learn.” What’s more, as a student at ICE, Calvin has had the opportunity to learn alongside not only Chef Michael — both in his career program courses and during elective classes in the Chocolate Lab — but also from other inspiring ICE chef instructors as well as prominent chefs through volunteering opportunities, like the annual Top Ten Pastry Awards, hosted by ICE each year.

At ICE, we make it our mission to help you take your inspiration to the next level — to pursue your passion and make a lifelong career of it. For Calvin, he’s been able to grasp the fundamentals of chocolate making and to explore his unique culinary voice. And it all began with a sip of delicious hot chocolate.

Ready to discover your own culinary voice? Learn more about ICE’s career Pastry & Baking Arts program.

Michael Laiskonis—Creative Director

In ICE’s Chocolate Lab, students get to take part in the bean-to-bar chocolate process, giving them a firsthand education on the importance of ingredient sourcing, refining and selection. Below, I’ve compiled some surprising facts about the different stages of the chocolate making process. These observations may be old hat to professional chocolate makers, but they are rarely — if ever — considered by chefs and consumers.

Raw Chocolate Sorting Beans Chocolate Lab Bean to Bar

Raw Beans
Straight out of the bag, fermented and dried beans present a serious microbiological risk, including E. coli and salmonella. Outbreaks linked to chocolate are rare, but the risk necessitates proper handling and storage. Simply put, I treat raw beans as if they were raw meat. Also, raw beans must be carefully sorted and cleaned of the various debris found in each bag (flat and moldy beans, stones, leaves, sticks, etc.). If that’s not enough, it isn’t uncommon for tropical moth eggs to hitch a ride on the surface of a cocoa bean! All of the beans that arrive at ICE’s lab are immediately bagged, sealed and chilled until roasting — before any of those tiny wings get an opportunity to hatch.

In addition to providing the only bacteria and moth “kill step” that renders the beans safe to consume, roasting allows for critical flavor development of the cocoa bean, further developing the precursors created during fermentation. Roasting also reduces the moisture content of the dried bean (chocolatiers always seek to minimize the amount of water in finished chocolate), which upon delivery is around 6-8%. Roasting parameters vary by bean type, origin, quantity and the desired flavor profiles—but typically roasters aim for 30-60 minutes or more at temperatures in the range of 300-350°F. Determining “doneness” is mostly subjective and instinctive. Chocolatiers primarily go by smell and taste, but also closely monitor the temperature of the bean mass throughout the process.

After roasting, the beans must be cracked and winnowed, separating the nibs from the shell. The shell alone can account for almost 15% of the roasted bean by weight and adversely affects the flavor and texture of finished chocolate. What’s more, the shell contains elevated levels of toxic heavy metals. Unsurprisingly, the acceptable industry standard for shell content in processed nibs is less than 1%.

Roasting Winnowing Chocolate Production Bean to Bar

Roasting beans and winnowed cocoa nibs

In most cocoa processing systems a “pre-grinding” of the nibs is necessary, to reduce both overall processing time and the eventual wear on refining machines. After grinding, the nibs are reduced to a thick paste referred to as “chocolate liquor,” with a mean particle size around 100 microns. (And yes, the term “liquor” is confusing to many, as there is no actual alcohol involved!)

Pressing Cocoa Butter
A portion of the liquor can be pressed to produce cocoa butter, which makes up roughly 50% of the beans’ weight. In the lab, this process takes one to two hours and nearly 65 tons of force. The remaining byproduct — known as “press cake” — can be further processed into cocoa powder.

Unlike the deodorized cocoa butter most chefs are familiar with, freshly pressed butter reflects the flavor compounds from the original beans. As most fine chocolate has a total fat content of 35-40% by weight, this additional cocoa butter can be added to boost the final percentage. For some single origin enthusiasts, this added butter makes or breaks a product’s bean-to-bar status, depending on whether or not the extra butter and original liquor are extracted from the same batch of beans.

Refining reduces the particle size of the liquor to an average of 20 microns. The human tongue can begin to detect grittiness at particle sizes larger than 35 microns, but reducing particle size below 20 microns increases the surface area of the cocoa butter, resulting in an unpleasantly thick consistency.

Refining is also the point in the bean-to-bar process at which other ingredients are introduced — sugar, additional cocoa butter, whole milk powder, etc. This process is achieved by an array of different machines, from stone melangeurs to roller refiners. Some systems, like our ball mill, work as a “universal,” allowing for “conching” to occur simultaneously with refining, due to the addition of temperature and airflow control.

Cocoa Butter Sifting Chocolate Refining Bean to Bar

Freshly pressed cocoa butter and sifting chocolate liquor

Conching — which involves heat, airflow and agitation — is critical for flavor development (removing unwanted volatile compounds), texture (coating the solid particles with cocoa butter) and further moisture reduction. This process can last for hours or days, depending on the desired results. However, conching time alone is not necessarily a measure of quality.

The final “recipe” for a batch of chocolate is determined by the addition of other ingredients, and will vary depending on such factors as bean type, desired flavor profile and application. The percentage you see on the label of finished chocolate refers to the total amount of cocoa solids by weight — meaning the nibs or liquor plus any added cocoa butter. This number alone is quantitative, not qualitative — a 70% chocolate may be 70% nibs or any equivalent combination of nibs and cocoa butter. Therefore, these percentages may not offer much insight into flavor, but they can tell us how much sugar was added. The percentage of sugar simply equals 100 minus the cocoa percentage (accounting for less than 1% additional vanilla or stabilizers like lecithin, etc.).

Before tempering, it is beneficial to sift or strain the finished chocolate through vibrating screens to remove any large particles that are difficult to refine — notably the “radicle” (or germ stem) that is a part of each bean. This hard stem is very bitter and can produce a gritty texture if left in the chocolate. Integrating a pass by powerful magnets into the sifting process can also eliminate the worry of any remaining hard metals in the chocolate.

Finished Chocolate Bean to Bar Aging

While the aging process is not well understood or widely researched, both large manufacturers and small-batch artisans agree that several weeks of aging finished chocolate allows for better, rounder flavor. Large companies inherently allow for this process in their distribution network, while artisan producers will hold chocolate batches in reserve for two months or more before tempering, molding and packaging.

Can’t wait to check out ICE’s Chocolate Lab? Learn more about ICE’s Pastry & Baking Arts program. 

Ever wonder what it takes to make one bar of chocolate? ICE Creative Director Michael Laiskonis, our resident chocolate expert, takes us through the entire process — from sourcing and roasting, to refining and conching, to finally molding and tasting — in less than a minute. But don’t be fooled by the video: though it may seem like a piece of (chocolate) cake, careful thought and calculation goes into each stage. According to Chef Michael, “Every step of the chocolate-making process, from fruit to bean to bar, presents an opportunity to influence the flavor and texture of the finished chocolate.”

Sweet tooth piqued? Discover how you can become a pastry pro with ICE’s award-winning career training programs by clicking here

It’s hard to believe that it’s been two years since we launched ICE’s bean-to-bar Chocolate Lab (the first education-focused one of its kind!). We decided to check in with ICE’s Creative Director Michael Laiskonis to find out what he’s been up to. As it turns out: a lot.

Having produced over 120 batches of chocolate with beans sourced from more than 20 countries, the Chocolate Lab has given Chef Michael the chance to tinker with each step of the chocolate-making process and bring out the best qualities in each bean. What’s more, Chef Michael has been meticulously tracking these changes and differences in process and flavor, which he then shares with interested students and colleagues in a number of hands-on classes at ICE.

Our Pastry & Baking Arts students have also had the opportunity to swap textbooks for hands-on experience with Chef Michael inside the Chocolate Lab, benefitting from a full understanding of the bean-to-bar process.. Watch below our two-year check in with Chef Michael.

Want to study in the ICE Chocolate Lab with Chef Michael? Click here for more information on ICE’s Pastry & Baking Arts program.

By Michael Laiskonis—ICE Creative Director

The final steps in processing our bean-to-bar chocolate make up the longest phase of the manufacturing process—a waiting game where the true essence of the bean, its complex flavor and its silky texture are unlocked. At this point, we focus on physically breaking the bean’s coarse texture, revealing subtleties beneath its bitter astringency and liberating its cocoa butter. Though we add ingredients at this stage, there is also an aspect of elimination—the refining stage is followed by conching, which peels away unwanted volatile flavors.

Sifting the Finished Chocolate

My last post dealt with handling the roasted bean—crushing it into nibs, separating its shell, grinding it into fluid cocoa liquor and extracting pure cocoa butter. During this final stage, the chocolate maker faces the challenge of tasting a bean’s full potential and identifying the subtle nuances within. While the goal of the “craft” chocolate maker working primarily in single origin batches is often to enable the expression of that bean’s inner essence, an industrial manufacturer’s typical aim is to create consistency from batch to batch, from year to year. Neither approach is qualitatively better or more difficult—just two possible approaches employed in the final stage of chocolate making.


Different kinds of machines can carry out the task of refining (stone melangeurs, roller refiners, scraped-surface refiners, etc.). In the lab, our coarse chocolate liquor enters a 10-kilogram capacity ball mill—a temperature-controlled tank that contains roughly 60 pounds of hardened steel-grinding media (ball bearings, essentially, in two sizes). With agitation, the steel balls begin breaking down the fairly large particles in the liquor, refining them down to a target of around 20 microns—in terms of scale, one micron (µm) is one-millionth of a meter (or one-thousandth of a millimeter). More accurately, true particle size in chocolate will lie along a curve, or a distribution, some smaller and some larger than our target. Looking closely at the structure of chocolate, it is simply very small solid particles (cocoa solids, sugar and sometimes milk solids) dispersed in fat—cocoa butter. Because the threshold of perception of a particle on our palate is in the neighborhood of about 35µm, a smooth, creamy mouthfeel depends upon breaking down the solids below that mark. Particles that are too small (below 15µm), however, will create too much surface area for the available cocoa butter, thus adversely affecting the flow properties of the chocolate with increased viscosity.

Most often, we add our ground liquor to the ball mill to refine for some time before adding any other ingredients. As the liquor continues to break down, more of its cocoa butter is released, providing sufficient fluidity to begin processing additional dry ingredients, namely sugar and, in the case of milk chocolate, whole milk powder. Virtually all of our chocolate receives an additional boost of cocoa butter as well. Vanilla, a common but not compulsory addition, can enter into the mix in various forms. I typically chop up whole vanilla beans and add them early in the refining process. Though the majority of the dozens of batches created in the lab have been of single origin, I have begun working on blending beans, and even introducing additional flavors—whole coffee beans, spices and nuts—to thoroughly integrate into the finished product. For our first attempt at a vegan milk chocolate, I replaced conventional milk powder with freeze-dried coconut milk. Refining time can vary, depending upon the batch size, particle size of the liquor and by agitation speed.

Measuring Particle Size on a Grind Gauge

measuring particle size on a grind gauge


Ball Mill

the ball mill

In addition to speed control, our ball mill also offers temperature control and heated airflow. Lacking a stand-alone conching machine, this heat and airflow help us replicate some of the effects of traditional conching. In basic terms, the conching phase is best described as heated agitation. Three key aspects of conching are moisture reduction, texture and flow enhancement and development of flavor. Residual moisture in chocolate can affect its flow properties, even though a great deal of the raw bean’s water was removed during the roast, trace amounts remain through the grinding and refining process. Prolonged mixing also helps ensure that all of the tiny solid particles are evenly dispersed in and coated by the cocoa butter, which improves mouthfeel and workability. And finally, the heat and forced air aid in driving off some of the remaining volatile acids – unwanted flavors that are a byproduct of fermentation back at the bean’s origin. Conching is an important part of the process, but each chocolate will require varying amounts. Long a marketing myth in the chocolate industry, a longer conching time does not necessarily equal higher quality. Some argue that excess conching may even destroy desirable flavors.

Once the chocolate is deemed ‘finished,’ it is extracted from the ball mill (we also employ two small stone grinders for smaller experimental test batches) and passed through a vibrating sifter—imagine a super-fine mesh strainer—which catches any particles not sufficiently refined. The radicle, the hard and bitter germ stem in every cocoa bean, may stubbornly evade grinding, along with the occasional bit of vanilla bean that sticks to the agitator. After sifting, it’s time for tempering and molding, right? Well, not so fast. Aging chocolate for a period of time, though unpredictable and not fully understood, is common practice. Some chocolate makers prefer to temper, mold and package chocolate immediately, others will age chocolate from two weeks to one month. Though there may be little one can do to change the finished product at that point, most believe that the true character of the chocolate will not reveal itself until it has had a minimum three-week mellowing period. One of the ongoing projects here in the lab is to hold back portions of each batch to sample at regular intervals to track some of these still-inexplicable changes over time.

As with other stages of the chocolate making process, success during refining relies on equal parts science, experience, taste, patience and arguably, some degree of intuition. The key is understanding that each part of the process presents a new set of variables. The next dispatch in this series will address formulation— the recipe development phase for each batch of chocolate.

Aging Chocolate

aging chocolate

Want to dive into the chocolate lab with Chef Michael? Click here for a list of his upcoming workshops at ICE.


By Michael Laiskonis—Creative Director

Every step of the chocolate-making process, from fruit to bean to bar, presents an opportunity to influence the flavor and texture of the finished chocolate. After harvesting, fermenting and drying at origin, beans are shipped around the world. Once received at the factory, raw cocoa undergoes several steps of transformation—what we call the “bean-to-bar” process. Previously I’ve discussed the bean-to-bar steps of sourcing and roasting. In this post, we will look at the intermediate steps necessary to turn flavorful roasted beans into the refined product we know and enjoy.

The nuanced flavors and smooth texture we associate with chocolate evolved during the Industrial Revolution, alongside the general advancement of technology and mechanization in the mid to late 19th century. This rise of the machine, so to speak, not only made chocolate products readily available to the masses, but it also catapulted what was a coarse bar or a rustic beverage to more sophisticated heights. Key players responsible for the machines and processes developed during this time remain some of the most recognized names in contemporary chocolate production today, including Van Houten, Peters, Nestlé and Lindt.

Machinery remains a constant in the contemporary chocolate-making process, and many visitors to the ICE Chocolate Lab are surprised by the sheer number and diversity of machines we employ. Below, I’ll explain the three processing steps, and their dedicated machines, that bridge the gap between roasting and refining.

Each bean has an outer shell, the germ stem (or radicle) and the nib, the latter of which contains a fat content of roughly 50-55%. Once out of the roaster and cooled, we must first break the bean and remove its shell. The removal of the shell is important for flavor, texture and food safety reasons: too much shell in our finished chocolate can produce a musty flavor and gritty texture and excessive wear and tear on our equipment. Additionally, while we have rendered the beans safe to handle from a microbial perspective by roasting, the high levels of heavy metals harbored in the shell are reason enough to discard them. In short, the shells do not positively impact flavor and are not considered “wholesome.”

cacao beans raw chocolate bean to bar chocolate

To remove the shells, we employ a winnowing machine, which yields only the nib, roughly 85% of its original weight, for further processing. We load the whole roasted beans into a hopper that funnels them through a rotating gear, crushing the bean and separating nibs from their shells, which have already loosened during the roasting phase. The fractured pieces then fall through a series of vibrating screens, causing the bits of nibs and shell to “dance” their way toward a vacuum which will suck the lighter shell from the screen while allowing the heavier nibs to pass through untouched. Our goal is to minimize the amount of shell in our nibs, while preventing any nibs from inadvertently getting discarded, so constant adjustment of the winnowing machine is necessary. We can control the rate of breaking the beans, the flow of particles along the screens and the intensity of the vacuum. Because shell weight can vary from bean to bean, we constantly monitor the nibs as they fall into a collection bin. From unsorted raw bean to cleaned nibs, it is not uncommon to lose 20-25% of our original weight of product.

Freed from their shells, the nibs then begin an intermediate grinding phase. Any number of grinding methods can perform this function, but in our lab we pass the nibs through a rotating hammer mill, which impacts the nibs at high speed, forcing them through three progressively smaller screens. The result is a coarse, semi-liquid paste that we refer to as chocolate “liquor”—confusing, as there is no alcohol present. This liquor is a suspension of dry cocoa solids, which vary in size up to a few hundred microns, in cocoa butter that is liberated from the nib and liquefied due to the heat of friction created during grinding. Each pass through the mill both saves time and reduces wear on the next stage of refining equipment. The final pass also often allows us the opportunity to isolate and remove a good deal of the hard, bitter radicles, which can contribute a harsh flavor and gritty texture to finished chocolate. Leaving the hammer mill, the liquor then enters a ball mill, along with any additional ingredients—at a minimum, sugar and additional cocoa butter—to achieve a final particle size near 20 microns.

micrometer chocolate mashup

The ability to press the added cocoa butter in the ball mill stage ourselves is one of the most exciting aspects of our production in the ICE Chocolate Lab. Up to two kilograms of our ground liquor is loaded into a heated pot and secured onto a hydraulic press. Gradually ramping up pressure over an hour or two—topping out at some 65 tons—will yield between 40-45% cocoa butter, which, unlike commercial deodorizer butter, emerges with significant flavor and aroma intact. This supplemental fat is used to boost the final cocoa butter content of the finished product, which for couverture-grade chocolate lies between 35-40%, maximizing fluidity and mouthfeel.

The machines we employ during these intermediary steps between roasting and refining typify how advancements in technology have helped make chocolate production more efficient and consistent. The next installment in this blog series will pick up with formulation, refining and conching—the final steps in which the chocolate maker can influence the finished product’s complex characteristics.

Interested in learning about chocolate firsthand? Click here for a list of upcoming classes with Chef Michael in the ICE Chocolate Lab.


Under the leadership of Creative Director Michael Laiskonis, every day in ICE’s Chocolate Lab is an opportunity for research and experimentation. Step inside the lab as we unwrap the chocolate-making process—from bean to bar—and discover just what it takes to create this beloved treat.

To discover the craft of bean-to-bar chocolate for yourself, request free information about ICE’s professional Pastry & Baking Arts program and continuing education courses for current pastry chefs.

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