Funded Research
2020 Funded Research
PROPOSAL 1, Ancient Stills
Funded $4500
Name: Eric Stroud
Email: eric@mohawkspirits.com
Occupation/Title:
Owner and distiller, Mohawk Spirits Distillery
Education:
PhD, Organic Chemistry (2013, Seton Hall University); MS Environmental Engineering (1997, NJIT); BS Chemical Engineering (1995, NJIT)
Distilling Experience:
Laboratory distillation and separations experience: 24 years. Craft distilling experience: 4 years
Research Experience:
20 years: Pfizer (research scientist, 1995-1998); Syvax Inc. (principal investigator, 1998-2004); SharkDefense Technologies (principal investigator, 2004-2015).
Please provide how your background experience will provide the foundation for your research:
Dr. Eric M. Stroud has dedicated his career to organic chemistry and novel chemical signal research. He led the group of scientists that discovered, isolated, and commercialized the first shark repellent pheromones, has formulated a variety of products for pharmaceutical, medical device, and invasive species control, and hold 11 patents.
Distillation is a core discipline in all of his work, past and present. Dr. Stroud is proficient on a number of distillation techniques, including vacuum fractional distillation, spinning band, and molecular falling film. In 2015, he founded Mohawk Spirits Distillery, Canajoharie, New York (Mohawk Spirits, LLC). Mohawk Spirits Distillery is the first farm distillery in Montgomery County, New York, and farms pawpaws, medlars, and rare fruits. Within 3 years, Mohawk Spirits was won nine medals in international spirits competitions, including two silver medals from ADI (2017, 2018). Mohawk Spirits is set up as a research distillery and laboratory, with a number of small scale separation units and laboratory equipment to study novel distillation techniques.
Dr. Stroud is a graduate of, and is currently a collaborating scientist with Seton Hall University and Dr. James E. Hanson in the Department of Arts and Sciences. Seton Hall University provides state of the art analytical equipment, such as time-of-flight mass spectroscopy (GC-MS(Tof) and nuclear magnetic resonance. The GC-MS(ToF) instrument is useful for quickly characterizing how well a still can separate and purify ethanol, as well as a flavor and fragrance compound identification.
Abstract:
Mohawk Spirits Distillery proposes to fabricate and evaluate three ancient still designs dating back to the 16th century in order to prove or disprove that such designs are practical in modern craft distilling. The ancient stills will be constructed using modern materials and a controlled study will be performed to measure the efficiency of the separation in each unit.
While the cucurbit, Moor’s head, and alembic designs have prevailed into our present time, there are historical distillation unit designs that warrant a new investigation using modern materials such as borosilicate glass, digital temperate controllers, and sensitive instrumental analysis. A modern investigation would provide obvious improvements over the limited materials used in the stills fabricated in 16th-18th centuries, such as temperature stability through the run. A controlled study using current scientific techniques may provide the craft distilling industry with a more efficient distillation process, a unique still design for brand differentiation, or a method to produce a superior-tasting distilled spirit.
Throughout the recorded history of distillation, numerous sketches of unusual and intricate designs appear from European alchemists, scientists, and philosophers. Many of these historical designs exist only in manuscripts. A few non-functioning extant stills are currently found in European museums or the Poli Grappa Museum (Bassano del Grappa, Italy). This proposal shall focus on the designs published by three scientist-philosophers:
1. Hieronymus Brunschwyg (1500) – “Twins” still (Figure 1, attached)
2. Nicholas Le Fevre – (1662) – Apparatus with “zigzag” condenser and moor’s head (Figure 2, attached)
3. Herman Boerhaave (1693) – Tall conical condenser (Figure 3, attached)
Proposal Background:
While no peer-reviewed publications on the recreation of ancient still designed has been found in our literature search, a proof of concept exists.
Mohawk Spirits Distillery recently researched an ancient design by Giambattisa della Porta (1535-1615) and successfully demonstrated a modern distillation process for grape marcs to produce an excellent brandy. The distillation unit was based on della Porta’s “hydra” and “pelican” sketches. Our research unit was constructed with Kimax glassware, with custom glass blowing performed by ProGlass (China) and Q-Glass II (New Jersey). Digital temperature controllers were applied to the boiler and each stage, a distillation was performed without any liquid coolant or closed-cycle refrigeration. A complete separation of the wash into an excellent consumable brandy product was made using only pressure drop (flash drum) and simple reflux principles. This distillation apparatus was assigned serial numbers and was registered with the TTB in 2019. A picture of this unit is attached to this proposal (Figure 4).
The recreation of the della Porta’s hydra-pelican is a successful proof of concept. Videos and pictures of this unit are available upon request. This research proposal seeks to investigate and validate other distillation unit designs from della Porta’s period.
Method:
Each unit will be constructed with borosilicate glass. Boiler capacity will be at a scale between 1 liter to 22 liters, depending on the complexity of the joints and access points. This size will produce enough consumable alcohol for an independent taste evaluation by a separate panel. The clear glass will allow the researcher to observe how the vapor-liquid equilibrium behaves during the distillation run.
Simple glassware modification will be done in-house with a brazing torch. Complex glassblowing will be performed by Q-Glass (Montvale, New Jersey). Each unit will be designed to incorporate at least one temperature sensor at the boiler and one temperature sensor in a condenser. Chemical analysis of the washes and distillates will be performed at Seton Hall University (South Orange, NJ) using a Leco Gas Chromatograph and Time-of-Flight Mass Spectrometer.
A standard test “wash” will be distilled in each unit. The test wash will be a standardized solution of purified water, pure ethanol (representing the “hearts”), pure acetone or acetaldehyde (representing the “foreshots”), pure methanol (representing the “heads”), and pure n-butanol (representing the “tails”). The efficiency of the separation and percent yield will be compared across all three units and a fourth modern pot still. For each fraction, odor, ease of operation, and duration of the distillation run will also be recorded. These fractions will be not consumed. A GC-MS(ToF) analysis using peak height area will be performed on the distillate fractions collected to further study the separation efficiency of the modern pot still versus the three historical designs.
Once the operation of each unit is well understood, a second series of comparisons will be performing using a food-grade (consumable) wash. If required, a pure copper metal sponge will be inserted in each still to bind organosulfides. The same wash will be used in all four units. The consumable spirits fraction from each unit will be sent to other evaluators for an organoleptic study and blinded judging.
Within one year of the award, the following milestones will be achieved:
1. MONTHS 1-3: Fabrication of the of the Brunschwyg, LeFevre, and Boerhaave apparatus
2. MONTH 4: Distilling the standard wash solution through each fabricated unit and a modern still
3. MONTH 5: Analyzing the distillates from all four units using GC-MS(ToF)
4. MONTH 6: Distilling a consumable wash through all four units for an independent tasting panel
5. MONTHS 7-8: Submission of all required reports to the TTB for registration of the stills and alcohol produced
6. MONTHS 9-10: A summary report to ADI on all results, along with the analytical data from the GC-MS(ToF)
7. MONTHS 11-12: Videos of each device in operation, suitable for the Internet or social media
Budget:
$4,500.00 – Total funds requested.
BREAKDOWN:
$3,000.00 – MATERIALS: Custom glassblowing costs, to be provided by Q-Glass II (Towaco, New Jersey), estimated at $1000.00 / still, inclusive of raw materials, glassblowing time, adjustments, and shipping.
$1,000.00 – ANALYSIS: Instrumental analysis, inclusive of gas, columns, and consumables. Estimated at $100/sample, 5 samples for standard solution analysis, 5 samples for consumable sample analysis
$500.00 – SERVICES: Video production and editing costs of the stills in operation, suitable for ADI use, conferences, and presentations
Mohawk Spirits Distillery will provide, gratis, professional time, mash material, yeasts, chemicals, containers, and distillery consumables. Mohawk Spirits Distillery will also ensure that all stills constructed are registered with the Alcohol and Tobacco Tax and Trade Bureau, and that all required monthly reports are submitted.
The final stills will be shipped for display and demonstration at any ADI conference or workflow, as requested.
Observations:
This research proposal will benefit the craft spirits industry by providing feasibility data on ancient still designs. If these designs prove practical, a craft distiller will be able to differentiate their products by marketing about the use of a historical design, e.g. produced using a “ancient design” or “16th century method”. These designs may prove to provide a better organoleptic profile than modern stills for certain types of spirits, hypothetically, fruit brandies. Potentially, these designs may have less energy input requirements than modern stills, or cheaper manufacturing costs.
References:
A primary reference for the historical designs considered in this research proposal are found in “Short History of the Art of Distillation”, Forbes, R. J. E. J Brill, Leiden, Holland. 1948. pp. 79-80, 207-210. Sketches of these units are attached to this proposal.
Boerhaave, H., “Elementa chemiae” (Leiden, 1731/1732, 2 vols.).
Boerhaave, H., “Elements de chimie” (paris, 1754, 6 vols.).
Brunschwygk, Hier, “Liber de arte distillandi de simplicibus oder Buch der rechten Kunst zu Distillieren die eintzigen dinge” (Strassburg, 1500, Johann Gruninger, the so-called “Small Book of Distillation).
Brunschwygk, Hier, “Liber de arte Distillandi de Compositis; Das Buch der waren Kunst zu distillieren die Composita and simplicia und das Buch thesaurus pauper” (Strassburg 23 Februar 1512, the so-called “Big Book of Distillation). (Other editions: Strassburg 1519, 1531; Francfort 1553, 1594, 1598, and several adaptions by Ulstad, Ryff, Uffenbach).
Lemery, N., “Cours de cymie contenant la maniere de faire les operations en usage dans la medicine par une method facile avec des instructions et raisonnements sur chaque operation our l’instruction de ceux qui veulent s’appliquer a cette science” (Paris, 1675, 1744, and 21 more editions).
Mohawk Spirits Distillery, online (February 6, 2020): http://www.mohawkspirits.com
PROPOSAL 2, Assessing the Utility of Molecular Rotational Resonance Spectrometry (MRRS) in Distilling Quality Control Operations in Three Distillery Settings
Funded $7000
Principal Investigator – Robin A. Felder PhD (Expert in Biochemistry)
Master Distiller Monte Piccolo Farm and Distillery
3135 Blandemar Dr.
Charlottesville, VA 22903
(M) 434-305-7979, robin@virginia.edu
Co-principal investigator – Brooks Pate PhD, Professor of Chemistry (Expert/Inventor of MRRS)
The University of Virginia
Charlottesville, VA 22903
Collaborator 1
Ian Glomski PhD (Expert in Microbiology), Master Distiller (Scientifically educated distiller with no significant spectroscopy experience who doesn’t use spectroscopy to guide his processes)
Vitae Spirits
Charlottesville VA 22903
Collaborator 2
Travis Hammond Distiller (Scientifically educated distiller with no significant spectroscopy experience who doesn’t use spectroscopy to guide his processes) (Bachelors of Science, Chemical Engineering), Operations Manager
Smooth Ambler Spirits
745 Industrial Park Rd.
Maxwelton, WV 24957
(W) 304-497-3123
Abstract
Research area: This grant application is related to the outcome and a continuation of the first grant awarded by Advisory Committee of Distilling Research.org in 2019 to myself to further the advancement of innovation in the craft distilling industry. The need that prompted both the grant submission and its funding was the use of a novel and revolutionary spectrometer to better identify and quantify flavor congeners during the distillation of spirits.
Research question to be tested: This proposal is to determine in three distilleries with decidedly different products if the MMRS (formerly called FFMRS) technology can translate from my highly controlled environment created by me, a seasoned spectroscopist/distiller to that of a spectroscopy-illiterate (yet scientifically minded) distillers.
Rationale for testing the question: We proved in three semesters of use of the “MRRS technology” (described in detail in this application) that we could not only measure known pear and peach congeners of interest, but also discovered previously unknown congeners affecting peach flavor profiles in Monte Piccolo spirits. This information has dramatically changed the fruit farming plan for the eau de vie products at Monte Piccolo Distillery to assure better flavors in the future.
Data/observations expected and their significance to the field of the craft distilling industry: We expect to generate hard data regarding the identity and quantity of each congener present in the heads, hearts, and tails fractions of at least one principle product from each distillery (as determined from sales income and/or quality of product important to each distillery). A questionnaire answered by each distiller will determine how the data would motivate changes to distillery operations in their future. Future studies will be funded by commercial sources to more widely disseminate this novel spectroscopic technique into the craft distiller industry.
Background/1st ADI Grant Award Progress report: The 1st ADI grant funded the collaboration between Monte Piccolo Distillery and the Department of Chemistry at The University of Virginia (Charlottesville, VA) to test the ability of the novel MRRS technology to measure the molecular content of the heads and hearts of pear eau-de-vie style fresh pear brandy. Normally, with a pot distillation apparatus, the heads and hearts “cut” is made at sensory discretion of the distiller. Similarly, with continuous distillation, the parameters that control the determine the distillate quality are set at the distiller’s discretion. Thus, the distillate can vary greatly based on the olfactory acuity of the distiller, congener content of the fruit due to seasonal variation, fermentation, and the distillation process itself. Until objective measures of congener concentrations can be made, the industry cannot begin to be able to know which steps in the entire production of spirits (i.e. from raw material to sip) are most critical to control. We demonstrated in our research, involving over 20 undergraduate chemistry students, that we could make objective measures of congeners with 11 carbon polymers or less in spirits collected during routine brandy distillation (1), based on previously published work (2).
Because of the high spectral purity of microwave light sources and high dynamic range, Chirped Pulse Fourier Transform Microwave (CP-FTMW) spectroscopy, also known as Molecular Rotational Resonance Spectroscopy (MRRS), provides unparalleled ability to unambiguously determine molecular structure. Since the rotational transition frequencies of a given species are determined purely by the moments of inertia of the molecule, mass shifts due to isotopic substitution generally cause relatively large shifts in transition frequency with respect to the spectral resolution. The acquisition and assignment of isotopically substituted spectra of a target species allow the determination of accurate experimental molecular structures with precision at the level of a few picometers, with application of Kraitchman’s equations or least linear squares fitting (3). Thankfully, the high dynamic range of MRRS generally allows for detection of the most common heavy atom isotopologues in natural abundance, as well. For representative results, see recent talks in the Publications section of my collaborator and colleague Brooks Pate PhD (4).
Completed Work:
1st phase of our grant, namely to determine if the identify and quantity of heads and heart congeners could be measured using MRRS. That work is scheduled to be presented to the 2020 ADI conference and an article has been published in Distiller magazine. (5, attached).
2nd phase, which is the subject of this proposal, is intended to test the MRRS technology on a broader number of distilled spirits originating from three different distilleries. If this second deployment phase is successful, then the technology can be deployed into a craft distillery for routine operation.
3rd future phase (not part of this proposal), would be to design and test an inline sampling apparatus that could be interfaced to the distillation process itself to guide the temperature ramping and dephlegmator temperature in a pot still to improve the quality of the hearts cut. Alternatively, the MRRS technology could be used to fine tune the condensing temperatures in a continuous still.
This MRRS technology has been published, commercialized, and has received awards (UVA’s Innovator of the Year, 2016) (4). However, it is relatively little known since it takes time for novel instrumentation to penetrate existing markets despite the vast improvements it brings to parameters such as sensitivity, selectivity, speed, and ultimately cost. Our preliminary work in Monte Piccolo distillery has demonstrate unequivocally that it brings hard data to the art of distilling. We plan on generating two distillation focused publications in peer reviewed literature to serve as a foundation for our future work in this area on the subject of pear and peach brandy distillation. A lay summary of the results of the 1st ADI grant has been published in Distiller Magazine to appear at the 2020 ADI conference (3). A presentation has been scheduled during the conference (5).
I am now on the Advisory Board of the ADI, a member of the Research Committee associated with the ADI, and have accepted to be Editor in Chief of Distilled Spirits which will be associated with both the ADI as well as Research Committee (details are forthcoming from the ADI). In addition, the following individuals have endorsed my work which was inspired by Dave Pickerell.
Dave Pickerell PhD, Managing Director Oak View Consulting, Louisville, KY (formerly Makers Mark)
Ian Glomski PhD, Vitae Sprits, Charlottesville, VA
Denver Riggleman, US Virginia Congressman (5th District), Owner Silverback Distillery
Alex Toomy, Owner Ragged Branch Distillery, Charlottesville, VA
Lyons Brown MBA (UVA Darden Business School graduate), Former chairman and chief executive officer of Brown-Forman Corporation, currently Altamar Brands, Charlottesville, VA
Materials, Methods, and timeline:
Month 1 – 3 – Collect specimens on site from Ian Glomski PhD (owner) at Vitae Spirits, Travis Hammond (Operations Manager) at Smooth Ambler Spirits, Robin Felder PhD (Owner) at Monte Piccolo, and assure proper sampling, quality control, labeling, and tracking (using pre bar coded specimen vials). We will select fractions before, during, and after the heads/hearts and hearts/tails cuts in triplicate for all the liquors produced at each of the three independent locations.
Month 4- 6 – Analyze the specimens in triplicate and reported as mean±standard error, perform data reduction, statistical analysis, and validation. The three distillers will meet and perform flavor analysis according to the standards at the Browns Forman which is one of the largest wine and spirits producers in the world, and owns the biggest-selling American whiskey, Jack Daniel’s. Its portfolio also includes Woodford Reserve and Old Forester Bourbons, Herradura and El Jimador Tequilas, Finlandia vodka and Chambord liqueur (Lyons Brown personal communication).
Month 6-12 – We will write our scientific articles and submit for consideration for publication in Scientific Spirits. We will also write, as required, an article for the ADI.
Analysis of specimens: The laboratory of Dr. Brooks Pate PhD (inventor of FFMRS) has been in operation for over a decade. He has built two of the first few FFMRS instruments in the World. These research full spectrum spectrometers are designed to identify any and all relatively small compounds in volatile liquids (such as the effluent from a still). This resource will be used to quality check the results from a smaller less expensive instruments. For example, fruit esters in brandies are generally under 11 carbons and thus are much easier and faster to quantify (real time) than compounds in pharmaceuticals.
Budget justification (Budget at the end of this proposal):
Supplies:
1. Specimen vials and bar codes associated with collecting and analyzing the effluents of the stills at Vitae Spirits, Smooth Ambler Spirits, and Monte Piccolo.
2. Specimen analytical fees will be paid to the laboratory of Dr. Brooks Pate PhD who maintains several MRRS instruments at The University of Virginia.
Interpretation of results: We will continue as per our current protocol and use standard purified materials (e.g. acetaldehyde, methanol, butanol, propanol, 2,4 decadieneoate, lactones, etc.) obtained commercially obtained from Sigma Aldrich and Perfumers Supply House. We will compare our results with the smelling impressions of the three distillers named in this grant (Glomski, Hammond, and Felder). Professional tasters will be available at the Browns Forman Corporation (personal communication from Lyons Brown to Robin Felder) to see how their impressions differ from our local craft distillers. We will use the sensory perception measures used by the professionals at the Browns Forman Corporation.
If successful with the findings how should research process further or what will this contribute to the distilling field?
We have demonstrated in a 2016 – 18 academic years that MRRS can be instrumental in improving the quality control of craft level distilled spirits. Based on this preliminary data and resulting publications (in preparation), we will be applying for grants from the National Science Foundation. Dr. Felder has generated over $70M in federal funding and published over 300 publications during his research career. He will ultimately retire full time into his craft distillery and use his scientific knowledge to further art and science of craft distilling.
Budget:
Specimen collection disposables: gloves (prevent human contamination), screw cap tubes, pipettes, marking pens, sequentially labelled bar codes, specimen racks (for repository use for reanalysis if necessary) = $400
Analyses – $125/specimen x 250 specimens = $31,250 (UVA contract bulk specimen rate, indirect costs included)
Mailing of specimens – since the specimens will not degrade significantly over 4 weeks we will bundle the specimens for bulk shipment from West Virginia (4 shipments @ $15/shipment = $60). Vitae and Montepiccolo will provide delivery to the Brooks Pate laboratory.
5 undergraduate students will be assigned to this year long academic credit-earning project. We anticipate finding up to 10 of the most abundant congeners per specimen yielding 2,500 data points that will need some extensive computer time for application of Kraitchman’s equations and least linear squares fitting for accurate determination of molecular structures with precision at the level of a few picometers.
All labor- no charge
Total: $31,710
(total and scope of the studies will be adjusted accordingly but still maintaining statistically sound and publishable results depending on the amount awarded by the ADI Research Council).
Budget Flexibility: The principal costs associated with this grant are scalable from ~$7,000 to $31,710 with the ability to gather statistically sound data by adjusting the number of specimens collected at each site and concentrating on the two distilleries that have no experience with MMRS.
References:
1. West, Channing, Miller, Thomas, Khan-Rafii, Noah, Plunkett, Emily, Chmielinski, Alexander, Hurst, John, Delaney, Thomas, Preston, Charles, Pate, Brooks, Neill, Justin L., Felder, Robin A.
Rotational Spectroscopy of Flavor Compounds in Peach Brandy for Process Monitoring in Craft Distilleries. 74th International Symposium on Molecular Spectroscopy DOI: 10.15278/isms. 2019.TL07
2. Xi, W.; Zheng, Q.; Lu, J.; Quan, J., Horticulture Plant Journal 3, 1-12 (2017).
3. Ohio State University, International Society of Molecular Spectroscopy 2012 Conference presentation RH03
4. http://faculty.virginia.edu/bpate-lab/cpftmw.html
5. Felder RA, Pate, B, Distiller Magazine (to be published Spring 2020)
PROPOSAL 3, How oxygen enters and interacts with distillate in whiskey barrels aged in various locations in aging warehouses
Funded $7000
Name: Conor O’Driscoll
Email: codriscoll@heavenhill.com
Occupation/Title:
Distillery Manager/Master Distiller, Heaven Hill Distillery
Education:
Bachelor of Chemical Engineering, University College Dublin, Ireland
Distilling Experience:
2004 – 2009, Brown-Forman Distillery, Louisville. 2009 – 2017, Woodford Reserve Distillery, Versailles. 2017 – 2019, Angel’s Envy Distillery, Louisville. 2019-present, Heaven Hill Distillery, Louisville.
Research Experience:
Co-investigator is Dr. Seth DeBolt, University Alumni Professor, University of KY. His resume is attached.
Please provide how your background experience will provide the foundation for your research:
In prior work, we have established the dissolved oxygen rates in wine barrels (Study in real-life conditions of liquid and oxygen transfers through a barrel when aging a wine in a cellar ZAC de la Garosse –250 rue des droits de l’Homme, 33 240 Saint-André-de-Cubzac NewsletterRetD@chene.fr-+33(0)7 89 63 65 54)(PDF attached). These data revealed that the negative pressure induced by barrel aging conditions results in abrupt changes in barrel oxygen levels over time in a wine setting. This is expected to be exasperated in a whiskey barrel, but to date no evidence has been produced on this subject. This research will provide foundational information on this subject. Given that whiskey barrels undergo dramatically different temperature conditions over the diurnal and seasonal range, we anticipate that understand dissolved oxygen in barrels will in turn allow for American whiskey producers to make detailed determinations on maturation cycles and predict how this may create oxygen driven reactions for flavor creation. Collectively, the output of these data could provide a rationale for reduced energy inputs, such as steam cycling, which in turn could reduce energy footprints and improve sustainability. Dr. DeBolt (co-investigator) has published over 80 peer-reviewed research articles on a variety of subjects including carbohydrate saccharification, wine, and whiskey barrels. The monitoring methods in this study are consistent with the experience he brings to the project in design and delivery of research. Furthermore, Master Distiller for Heaven Hill Conor O’Driscoll (Chemical Engineer) brings a wealth of experience in distilling and maturation facility operations and process chemistry. The teams at Canton Cooperage and Independent Stave Companies provide sophisticated support for all monitoring and barrel construction. Their cooperation in barrel comparisons will provide additional research outputs that are relevant to both craft and heritage distilleries. Further, Dr. DeBolt has published several papers on environmental monitoring, chemical analyses, and sensory profiling (see CV in appendix) and has gas chromatography-mass spectrometry (GC MS) and liquid chromatography tools dedicated to whiskey research. Methods relevant to this research involve environmental data logging, as well as mapping and modeling of data (DeBolt et al., 2008; Gollihue et al., 2018).
Abstract:
The project will define how oxygen enters and interacts with distillate in whiskey barrels aged in various locations in aging warehouses at Heaven Hill distillery, Bardstown KY, with toasted versus charred white oak barrels as primary treatments. Outcomes of the dissolved oxygen study will provide critical clues to inform cultural treatments and aging paradigms for achieving quality barrel-aged products.
Proposal Background:
Oxidation occurring in food products is generally thought to be negative and attributed to spoilage, in whiskey however this reaction is critical to flavor development. Though Fenton chemistry is still yet to be understood completely, the signs of this chemical process have been documented as ethanol changes to acetic acid and acetaldehyde1,2,3. Fenton chemistry in wine has been documented and while the mechanisms of this process are still being divulged4-5. the generation of hydrogen peroxide has been documented. The hydrogen peroxide is produced from phenolic compounds reacting with oxygen and the charge state is regenerated from iron and copper ions6-7. The implications of these reactions in whiskey maturation are extremely interesting and should be explored as many volatiles will be produced as has been previously observed in port8, cheese or cooking oil9-10. There are some factors that should be considered in influencing oxidation rates in whiskey that the process is going to be influenced by composition polyphenolic, transition metals content, pH, temperature and dissolved oxygen content5. Barrel wood after pyrolysis is biochar and would have the ability to adsorb and desorb various compounds and metals, this would be an interesting area of study to understand these relations particularly during secondary use of the barrel 11-1251,82. Thus, we propose to examine both charred and toasted barrels as independent variables.
Method:
Several in situ methods are embedded into the CHENOX device (patent pending). These devices deliver O2 and CO2 determinations, but we also embed pressure sensors for gaseous atmosphere, density measurement and spatial differences in pressure between the top and bottom of the barrel (assuming no rotation). These methods are standard and reported in Canton (2019) in the attached PDF. The data logging and reporting between different levels in the rickhouse is aided by the use of Heaven Hill maturation facilities. Here, we will compare the lower, middle, and upper floors of the rickhouse to determine statistical variation in pressure compared between floors. Statistical tests will be aided by the University of Kentucky James B Beam Institute for Kentucky Spirits. In-house statistician assistance is available to compare treatments across floors and between replicates.
Budget:
Please see attached project brief for full details.
Observations:
This research will provide critical data for any scale of distiller wishing to barrel age a spirit. It will provide knowledge on where to maximize oxygen driven reaction chemistry based on the position of the maturation facility and relate this information to logged temperature and humidity data. We will present this freely to the ADI community to allow craft distillers to how to mature their barrel-aged spirit. Depending on findings, we feel these data are going to be important for sustainability and deciding whether to age using steam cycling. It will point to the optimal point for oxygen intake rates, which are critically important to flavor development.
References:
In addition to the references listed in the attached proposal, the following work is also relevant:
DeBolt S, Ristic R, Iland PG, Ford CM (2008) Altered light interception reduces grape berry weight and modulates organic acid biosynthesis during development. HortScience 43: 957-961.
Canton Cooperage (2019) Study in real-life conditions of liquid and oxygen transfers through a barrel when aging wine in a cellar ZAC de la Garosse –250 rue des droits de l’Homme, 33 240 Saint-André-de-Cubzac NewsletterRetD@chene.fr-+33(0)7 89 63 65 54
Gollihue, J, Mitchell Richmond, Meera Nair, Harlan Wheatley and Seth DeBolt (2018) Liberation of recalcitrant cell wall sugars from oak barrels into bourbon whiskey during aging Scientific Reports 15899.