Unique Attar Distillation - In house

[AlHind Oud]

3rd fraction, very distinct color than the first two. Very interesting, deep base notes.

 

[Joe]

Very different color....why?

 

[AlHind Oud]

Very different color....why?

The combination of sandalwood, kinam, and oud, when heated at a slightly higher temperature, produces that color. In general base fraction is darker.

 

[Joe]

The combination of sandalwood, kinam, and oud, when heated at a slightly higher temperature, produces that color. In general base fraction is darker.

It's beautiful! All my fellow artisans make me want to distill!

 

[LasLunas]

Extremely simplified:
Distillation of substrates containing azulene or derivatives yield blueish colors which oxidize to green/yellow upon exposure to oxidants. German Chamomile is an example. "The aroma associated with chamazulene is of grass/hay and some would say cured tobacco, mixed with hints of black tea and flower nectar." Chamazulene is also found in essential oils distilled from Blue Tansy and Yarrow, while guaiazulene is found in Blue Cypress essential oils. Some species of agarwood producing trees contain azulene compounds thus blue and green fractions are observed during distillation.

Sesquiterpenes lack a functional group that absorbs hv in the visible portion of spectrum while the sesquiterpenoids commonly contain oxygenated functional groups (chromophores) responsible for observed colors. The lightest molecular weight sesquiterpenoids with lactones and pyran-rings typically vaporize to yield yellows and orange. Azulenes are heavier than oils distilled in first fractions, and if present in substrate we will observe blues and greens in the next fraction(s). If heavy yellow oils present we might only observe greenish oils unless temperature differential for vaporization is sufficient to observe condensation of each compound, highly unlikely here.
The heavier molecular weight sesquiterpenoids require a higher temperature to vaporize and are responsible for reds, violet and brown color oils, the actual colors directly related to oxygenated substituents and structures.

The various constituents can be separated using Column Chromatography or TLC, and one may observe all of the various colors, hues and intensities of individual compounds. Clearly Oudh Oil is too precious to play around with chromatography for the fun of it, but if you are interested there are plenty of inexpensive methods for demonstration.

Explanation is greatly simplified and if discussion is desired we should start a new thread or PM.

 

[Joe]

Extremely simplified:
Distillation of substrates containing azulene or derivatives yield blueish colors which oxidize to green/yellow upon exposure to oxidants. German Chamomile is an example. "The aroma associated with chamazulene is of grass/hay and some would say cured tobacco, mixed with hints of black tea and flower nectar." Chamazulene is also found in essential oils distilled from Blue Tansy and Yarrow, while guaiazulene is found in Blue Cypress essential oils. Some species of agarwood producing trees contain azulene compounds thus blue and green fractions are observed during distillation.

Sesquiterpenes lack a functional group that absorbs hv in the visible portion of spectrum while the sesquiterpenoids commonly contain oxygenated functional groups (chromophores) responsible for observed colors. The lightest molecular weight sesquiterpenoids with lactones and pyran-rings typically vaporize to yield yellows and orange. Azulenes are heavier than oils distilled in first fractions, and if present in substrate we will observe blues and greens in the next fraction(s). If heavy yellow oils present we might only observe greenish oils unless temperature differential for vaporization is sufficient to observe condensation of each compound, highly unlikely here.
The heavier molecular weight sesquiterpenoids require a higher temperature to vaporize and are responsible for reds, violet and brown color oils, the actual colors directly related to oxygenated substituents and structures.

The various constituents can be separated using Column Chromatography or TLC, and one may observe all of the various colors, hues and intensities of individual compounds. Clearly Oudh Oil is too precious to play around with chromatography for the fun of it, but if you are interested there are plenty of inexpensive methods for demonstration.

Explanation is greatly simplified and if discussion is desired we should start a new thread or PM.

Got it. Thanks. Reminds of of chemistry class in school!

 

[SteveE]

In organic chemistry, which takes me back 30 years in my career, we would use certain compounds to absorb water out of otherwise organic mixtures – – in some cases to keep them from exploding.
How do you get the water completely out of the oil? Do you just wait for it to separate naturally? Is there still some water in the oil? Does that bother you or is it a concern?

 

[Mr.P]

I recall Mehmet discussing some kind of controlled heat treatment immediately post distillation. I am remembering an open bottle in a heated chamber, I think using sun lamps. I have also read descriptions from other producers about leaving bottles with a permeable cap for some period of time after distillation, and something like cheese cloth or fabric or something to keep dust etc. from falling in of course.

 

[LasLunas]

Got it. Thanks. Reminds of of chemistry

In organic chemistry, which takes me back 30 years in my career, we would use certain compounds to absorb water out of otherwise organic mixtures – – in some cases to keep them from exploding.
How do you get the water completely out of the oil? Do you just wait for it to separate naturally? Is there still some water in the oil? Does that bother you or is it a concern?

Depends on purpose and when you need to remove water from reactions...is it to prevent explosion? This is of extreme importance during synthesis, collection, etc., or is the goal to remove minute amounts of water from final product oils? Are you concerned with oxidation? hydrolysis? There are various techniques, but beware of potential product losses, etc from simple one step methods. Using a zeolite to remove polar molecules (water) sounds simple, but how much oil might adhere to surface pores??? And now you will have a more complex issue facing you.

Simple technique: Chill the vessel you are separating and decanting oil from, drain water, grab a vial to decant first small bit of oil, then decant remaining oil into receiving vessel.

You can combine all "first few drops of oil" fractions into separator funnel or cylinder, chill, allow further phase separation, then dispose of any additional water. This probably isn't ideal, but simple and doable for even a beginner.

One should only be working with potentially explosive syntheses after acquiring sufficient know how and technique perfection - take this advice from someone who managed to create an explosion that blew out the exhaust system, send shards if glass into the ceiling and start a fire in the lab when solution dripped into electrical outlets after explosion during synthesis of a hexacyanoruthenate(II) salt combining diethyl ether and a perchlorate in the reaction vessel. All this as an undergraduate summer intern......clearly should not have been left alone. Unfortunately to this day I will not light the gas BBQ grill.

So if you really must remove water you should understand why, when and how....and take the path of least resistance.

 

[Mr.P]

Extremely simplified:
Distillation of substrates containing azulene or derivatives yield blueish colors which oxidize to green/yellow upon exposure to oxidants. German Chamomile is an example. "The aroma associated with chamazulene is of grass/hay and some would say cured tobacco, mixed with hints of black tea and flower nectar." Chamazulene is also found in essential oils distilled from Blue Tansy and Yarrow, while guaiazulene is found in Blue Cypress essential oils. Some species of agarwood producing trees contain azulene compounds thus blue and green fractions are observed during distillation.

Sesquiterpenes lack a functional group that absorbs hv in the visible portion of spectrum while the sesquiterpenoids commonly contain oxygenated functional groups (chromophores) responsible for observed colors. The lightest molecular weight sesquiterpenoids with lactones and pyran-rings typically vaporize to yield yellows and orange. Azulenes are heavier than oils distilled in first fractions, and if present in substrate we will observe blues and greens in the next fraction(s). If heavy yellow oils present we might only observe greenish oils unless temperature differential for vaporization is sufficient to observe condensation of each compound, highly unlikely here.
The heavier molecular weight sesquiterpenoids require a higher temperature to vaporize and are responsible for reds, violet and brown color oils, the actual colors directly related to oxygenated substituents and structures.

The various constituents can be separated using Column Chromatography or TLC, and one may observe all of the various colors, hues and intensities of individual compounds. Clearly Oudh Oil is too precious to play around with chromatography for the fun of it, but if you are interested there are plenty of inexpensive methods for demonstration.

Explanation is greatly simplified and if discussion is desired we should start a new thread or PM.

Interesting - so there's a whole spectrum of different pigmented molecules (sesquiterpenoids in this case) in the oud, and distilling into separate fractions kind of sort them out because there are differences in mass or volatility associated with the color changes.

I also wonder about chemical changes that happen in the mash itself prior to molecules traveling over in the steam. I have some questions about this in relation to sandalwood in particular but I'm wondering if in this particular case do you think some of those lighter weight pale yellow or green blue sesquiterpenoids get chemically transformed into the heavier red colored ones during the distillation process as they are being cooked and boiled in the mash?

There can be a fair bit of reflux during distillation- meaning an individual molecule may evaporate and recondense many times before it ends up passing to the condenser, some stills have special inserts to adjust the rate at which this happens. I think in this case by retaining these molecules for a while you have the opportunity to transform them by heat

[I responded before I realized that this was a thread started by @AlHind Oud and I feel like I hijacked it a bit. I would not mind at all if moderators moved my posts to a separate thread]

 

[LasLunas]

Interesting - so there's a whole spectrum of different pigmented molecules (sesquiterpenoids in this case) in the oud, and distilling into separate fractions kind of sort them out because there are differences in mass or volatility associated with the color changes.

I also wonder about chemical changes that happen in the mash itself prior to molecules traveling over in the steam. I have some questions about this in relation to sandalwood in particular but I'm wondering if in this particular case do you think some of those lighter weight pale yellow or green blue sesquiterpenoids get chemically transformed into the heavier red colored ones during the distillation process as they are being cooked and boiled in the mash?

There can be a fair bit of reflux during distillation- meaning an individual molecule may evaporate and recondense many times before it ends up passing to the condenser, some stills have special inserts to adjust the rate at which this happens. I think in this case by retaining these molecules for a while you have td he opportunity to transform them by heat

[I responded before I realized that this was a thread started by @AlHind Oud and I feel like I hijacked it a bit. I would not mind at all if moderators moved my posts to a separate thread]

Thermal oxidation definitely pushes cleavage and formation of bonds resulting in different molecules. Was a thread started for this discussion? I do not wish to be rude either.

 

[AlHind Oud]

3rd and final fraction. Releasing soon, get ready!

 

[Joe]

3rd and final fraction. Releasing soon, get ready!

View attachment 49937
View attachment 49938

Congratulations! What’s the aroma like?

 

[AlHind Oud]

Congratulations! What’s the aroma like?

Too early to tell; I still need to mix all the fractions. I will write notes on the smell when released. Stay tuned.

 

[LasLunas]

Thermal oxidation definitely pushes cleavage and formation of bonds resulting in different molecules. Was a thread started for this discussion? I do not wish to be rude either.

Example of reaction that happens at 100 C: Bicycle [6,2,0] decapentaene, a liquid orange red oil, when heated to 100 C dimerizes converting to a yellow oil consisting of three (3) eight carbon unsaturated rings.
I will venture that both the time and temperature of distillation itself may result in such rearrangements of constituents in the pot.

 

[Joe]

Example of reaction that happens at 100 C: Bicycle [6,2,0] decapentaene, a liquid orange red oil, when heated to 100 C dimerizes converting to a yellow oil consisting of three (3) eight carbon unsaturated rings.
I will venture that both the time and temperature of distillation itself may result in such rearrangements of constituents in the pot.

oh, okay, darling.

 

[Mr.P]

Example of reaction that happens at 100 C: Bicycle [6,2,0] decapentaene, a liquid orange red oil, when heated to 100 C dimerizes converting to a yellow oil consisting of three (3) eight carbon unsaturated rings.
I will venture that both the time and temperature of distillation itself may result in such rearrangements of constituents in the pot.

what about rearrangements post-distillation during curing or storage? I have the most primitive understanding… There are interactions with oxygen and interactions between the different constituents of the oil that are now brought together in high concentration. Are other types of rearranging going on as well at lower temps? I guess there's some probability of any reaction happening... just a matter of whether it happens at an appreciable rate.

 

[LasLunas]

what about rearrangements post-distillation during curing or storage? I have the most primitive understanding… There are interactions with oxygen and interactions between the different constituents of the oil that are now brought together in high concentration. Are other types of rearranging going on as well at lower temps? I guess there's some probability of any reaction happening... just a matter of whether it happens at an appreciable rate.

Let me start with I am NOT an expert Organic Chemist, but I am sufficiently knowledgeable. As a Physical Chemist (Yes, the dreaded P.Chem!) I am baffled by the amount of time the distilled oil spends in contact with hydrofoil in a collection vessel. Why?

We have an unsaturated fatty acid in contact with water and whatever enzymes and bacterial components may have carried over or been present. Heat typically increases kinetics in forward direction due to movement of molecules. Moisture in contact with oils (fatty acids) cause hydrolysis of unsaturated oils and thus generate free fatty acids in the product which then results in production of free radicals, especially at the oil/water interface. The free radical with its unpaired electron attacks the unsaturated (double) bonds of the oil. There must be a byproduct(s) of the reaction, and that includes hydroperoxides which are simply additional reactive molecules introduced into the product.

Light (hv) provides energy to catalyze oxidation, so my brain wonders why the distillate flasks are often clear glass out in the open room? Why not use materials to filter hv?

I don't know if there are enzymes present or if bacterial species survive the process, but if so then one should expect enzymatic lipolysis to proceed as well.

Maybe, all of this oxidation contributes to the aroma profile of Oudh oils? I don't know. I can state that these reactions are avoided at all costs in the food industry as oxidized oils are typically denoted as rancid. The oxidized by products in oils for consumption tend to have either soapy or bitter, medicinal notes, and even metallic odors which may be associated with equipment utilized in processing. Since I often read of bitter and medicinal notes in Oudh oils I wonder if they are the product of auto-oxidation processes? Consumers have come to expect such aromas without understanding why they might be present. I am not sure.

I understand the reason that producers heat or sun their oils after distillation - it is crucial to remove any remaining moisture. However, this warm exposure to air only allows for additional oxidation, polymerization and incorporation of malicious by products. Again, the aromas might be normalized to the consumer and producer expectations.

Every time I see a cylinder from a distillation with a picture of oil on top of a column of water my brain goes into overdrive which is difficult for me to shut down, it is like a cascade of overflowing thoughts and equations. Difficult to explain sometimes.
BUT... I just muse about placing some sort of ultra thin, layer or filter in the collector which is permeable to the waterborne fraction yet sequesters the lipid fraction. Maybe no such baby exists, but I would bet otherwise, I will find it this week!

This would solve the potential issue of moisture in the oil from the get go, maybe even eliminate the necessity of heating or exposure to sunlight in an open container. I am just thinking out loud I guess.

Why does aging an Oudh oil smooth it out so to speak? Perhaps the reactive species are consumed with time, oils appear more viscous due to some polymerization, changes in visible color, etc. Some of those reactive species carry the bitter, sharp odors and require depletion to improve aroma profile in time. So why not prevent unpleasant reactive species up front?

The kinetics of each reaction may differ, and the by product of one reaction may speed up, or slow down a separate reaction. Data intensive questions to answer. Many aliquots during each part of the process, carefully controlled light exposure, precise temperature data, moisture content measurements, free acid data, oxygenated species content....
I imagine there is enough challenge for at least five Ph.D. dissertations and some steady work for a few Post Docs to unravel the Oudh oil distillation chemistry on such a detailed basis.

Artisan distillers have learned to identify some of the process issues by trial and error and adapt their processes accordingly, and I have the utmost respect for their knowledge and abilities. Yet, there is still room for hard science in this business. I will venture a guess that as production continues ti become more commercialized using cultivated substrates that the industrial methods will have the $$$ to look into nuances such as a "Pampers" liner in the initial receiving vessel for each fraction, maybe even inline constituent identification as it distills over....oh yeah!

I need to look for some sort of water permeable interface to prevent moisture in column from reacting with oil it is in contact with, sometimes for may days, then get someone to experiment with the process!

 

[LasLunas]

oh, okay, darling.

Sorry...

 

[Mr.P]

Let me start with I am NOT an expert Organic Chemist, but I am sufficiently knowledgeable. As a Physical Chemist (Yes, the dreaded P.Chem!) I am baffled by the amount of time the distilled oil spends in contact with hydrofoil in a collection vessel. Why?

We have an unsaturated fatty acid in contact with water and whatever enzymes and bacterial components may have carried over or been present. Heat typically increases kinetics in forward direction due to movement of molecules. Moisture in contact with oils (fatty acids) cause hydrolysis of unsaturated oils and thus generate free fatty acids in the product which then results in production of free radicals, especially at the oil/water interface. The free radical with its unpaired electron attacks the unsaturated (double) bonds of the oil. There must be a byproduct(s) of the reaction, and that includes hydroperoxides which are simply additional reactive molecules introduced into the product.

Light (hv) provides energy to catalyze oxidation, so my brain wonders why the distillate flasks are often clear glass out in the open room? Why not use materials to filter hv?

I don't know if there are enzymes present or if bacterial species survive the process, but if so then one should expect enzymatic lipolysis to proceed as well.

Maybe, all of this oxidation contributes to the aroma profile of Oudh oils? I don't know. I can state that these reactions are avoided at all costs in the food industry as oxidized oils are typically denoted as rancid. The oxidized by products in oils for consumption tend to have either soapy or bitter, medicinal notes, and even metallic odors which may be associated with equipment utilized in processing. Since I often read of bitter and medicinal notes in Oudh oils I wonder if they are the product of auto-oxidation processes? Consumers have come to expect such aromas without understanding why they might be present. I am not sure.

I understand the reason that producers heat or sun their oils after distillation - it is crucial to remove any remaining moisture. However, this warm exposure to air only allows for additional oxidation, polymerization and incorporation of malicious by products. Again, the aromas might be normalized to the consumer and producer expectations.

Every time I see a cylinder from a distillation with a picture of oil on top of a column of water my brain goes into overdrive which is difficult for me to shut down, it is like a cascade of overflowing thoughts and equations. Difficult to explain sometimes.
BUT... I just muse about placing some sort of ultra thin, layer or filter in the collector which is permeable to the waterborne fraction yet sequesters the lipid fraction. Maybe no such baby exists, but I would bet otherwise, I will find it this week!

This would solve the potential issue of moisture in the oil from the get go, maybe even eliminate the necessity of heating or exposure to sunlight in an open container. I am just thinking out loud I guess.

Why does aging an Oudh oil smooth it out so to speak? Perhaps the reactive species are consumed with time, oils appear more viscous due to some polymerization, changes in visible color, etc. Some of those reactive species carry the bitter, sharp odors and require depletion to improve aroma profile in time. So why not prevent unpleasant reactive species up front?

The kinetics of each reaction may differ, and the by product of one reaction may speed up, or slow down a separate reaction. Data intensive questions to answer. Many aliquots during each part of the process, carefully controlled light exposure, precise temperature data, moisture content measurements, free acid data, oxygenated species content....
I imagine there is enough challenge for at least five Ph.D. dissertations and some steady work for a few Post Docs to unravel the Oudh oil distillation chemistry on such a detailed basis.

Artisan distillers have learned to identify some of the process issues by trial and error and adapt their processes accordingly, and I have the utmost respect for their knowledge and abilities. Yet, there is still room for hard science in this business. I will venture a guess that as production continues ti become more commercialized using cultivated substrates that the industrial methods will have the $$$ to look into nuances such as a "Pampers" liner in the initial receiving vessel for each fraction, maybe even inline constituent identification as it distills over....oh yeah!

I need to look for some sort of water permeable interface to prevent moisture in column from reacting with oil it is in contact with, sometimes for may days, then get someone to experiment with the process!

thanks for that. I'm curious… You mentioned fatty acid in contact with water but I was under the impression that those are not volatile and so they would not be involved in whatever chemistry was happening in the condenser. Obviously there are fatty acids along with all kinds of non-volatile plant material in the boiler itself so maybe that's where you are referring to. Do I have this more or less correct?