Forget that old coffee ring effects:”whiskey network”new hot


Whiskey of the network model is for each sample of the test of American whiskey. (l-r)Four Roses Heaven Hill, maker's Mark Cask Strength, Jack Daniels Single Barrel Proof, dad Van Winkle family storage for 23 years, the Park retained the Double Oak.
Zoom / Whiskey of the network model is for each sample of the test of American whiskey. (l-r)Four Roses Heaven Hill, maker’s Mark Cask Strength, Jack Daniels Single Barrel Proof, dad Van Winkle family storage for 23 years, the Park retained the Double Oak.

American whiskey is unique, from their Scottish counterparts in a very unique way: they leave an unusual mesh pattern as the droplets dry up, these nets are different for different brands—make them the same”fingerprint.” It is a property, not only can be used to tell the difference between brands of American whiskey but one day can lead to an effective method for the identification of counterfeit products, according to a new article published in ACS Nano.

As we reported last year, Stewart Williams, Professor of Mechanical Engineering at the University of Louisville in Kentucky, noted that one day, if he diluted a drop of Bourbon whiskey, let it evaporate under carefully controlled conditions, it formed what he terms a”whiskey network”: thin strands in the form of a variety of plaid pattern, similar to the network of blood vessels. Out of curiosity, he decided to further investigate the different types of whisky plus a bottle of Scottish Glen right whisky for comparison. This is the perfect project for his sabbatical research on colloids(suspended particles in a medium, like jelly cream, wine, and whiskey)at North Carolina State University.

Fundamentally, this is the same basic mechanism as the”coffee ring effect,”when a single evaporation of the liquid and the solid has been dissolved in a liquid(such as coffee)form a distinct ring. It happened because evaporation occurs faster at the edge than in the center. Any remaining liquid flows to the edges to fill in the blanks, drag these solid. Mixed in a solvent(such as water or ethanol)to reduce the effect, as long as the drops are very small. Large droplets produce a more uniform stain.

In these early test, Williams test, 66 American whiskey; only one did not create a web page. Whiskey network appears to be related to alcohol content. Williams and his team have diluted the whiskey with water drop to about 40-50%of proved. Specifically, they found that if the alcohol excess levels higher than 30%, there will only be one unified film; less than 10%, you of the coffee ring pattern. Only in the middle of the alcohol by volume levels between 20%and 25%, you get these unique Viagra structure.

The next step is to try to identify the specific chemicals responsible, if this mode can be used as a fingerprint of a specific brand. For this new set of experiments, his laboratory tested 66 American whiskey(56 Bourbons, 10), 13 other whiskey and 6 of the United Nations year of the whiskey, all subject to the same test conditions: 25 per cent of alcohol by volume, with 1 mm droplets. “To date we have tested close to 100 samples, we have yet to find a non-American whisky to form a network in these conditions,”said Williams.

A drop of American whiskey evaporated to form a unique net-like pattern of the solute.
Zoom / A drop of American whiskey evaporated to form a unique net-like pattern of the solute.

ACS Nano

This solid, there is whiskey, but also contribute to the prestige of the model behind. For example, whiskey aged in New charred barrels usually have a more solid, particularly those readily dissolved in ethanol. “We believe that the increase in the extracted solid from the United States the whiskey is responsible for these patterns,”said Williams. “Chemicals originated from fermentation and distillation, but the real experienced dramatic changes in maturity.”

Next, Ms. Williams summarized the pattern ID of the test to confirm the unique network model for different brands can be repeated. He used three brands of whisky from the same distillery in the experiment: the Old Weller Antique,W. L. Weller12 year, W. L. Weller Special Reserve…. He and his team tested 30 drops of each(90 drops, all approximately 2 mm in diameter or”size of a very large period”), and take a digital image of each.

Then they randomly select 25 drops from the same whiskey and average the results to create a representative”library”of measurement, whiskey, for future comparison purposes, per Williams. “We compared the remaining decline, the whiskey library,”he said. “Whiskey is successful with their brand of 90% of the time.”

Another experiment, Williams soared a”control whiskey”with chemicals, such as vanillin, tannin, or lignin(all compounds taste), found that there is a significant change caused by the whiskey network mode. “This provides evidence that chemicals related to flavor of the impact of the final structure,”he said. “In other words, each whiskey buckle is different, because the chemicals, so that their single is different. Thus, the resulting network structure reflects its content.”

Williams is still capable of producing a mesh pattern for non-us through the whiskey buckle water-ethanol liquid fatty acids and by performing a test of a highly waterproof surface, and therefore, the droplets beaded up very well.

Analysis of the microscope image Web page pattern from American whiskey the same.
Zoom / Analysis of the microscope image Web page pattern from American whiskey samples.

A. D. Carrithers et al./ ACS Nano

The real question is whether be able to tell the difference between the old and young whiskey(or good and bad)simply by evaporation distillation pull in the appropriate environmental conditions. Such techniques can be used for quality control in the brewery or for the detection of counterfeit products. Preliminary results are promising, but the whiskey is incredibly complex, containing thousands of chemicals.

“Unfortunately, we will not be able to tell a whisky consisting of the use of this analysis,”said Williams. “However, we can use this technology to determine if it is an American whiskey or not, i.e. whether it forms a web or not.” Even more statistical analysis is necessary, the purpose is towards standardized testing program, the previous techniques will help distinguish between the different American whiskies. Although it does not replace the more sophisticated chemical techniques, such as chromatography, it may prove to be useful as a simple pre-analysis test, to determine whether it is worth doing a more expensive and time-consuming chemical tests.

Because Williams like almost everyone these days, mostly working at home, he used this time to work, the development of a smartphone-based visualization platform, so that everyone can make and image of their whisky network at home, little more than a cheap lens(which runs about $ 7 on Amazon)or an USB microscope(which costs about $ 20). He hoped that the later instructions to his research website(including a gallery of the whiskey-a web image)in time for this weekend, in the case of fever is to give you, you are looking for a fun DIY project.

That is to say,”the best image to complete on a standard light microscope,”said Williams. “The light from the side illuminated structure, in these images the reflected light line. You may notice that the image is mostly black features white. These characteristics are reflective camera.”

DOI:ACS Nano by 2020. 10.1021/acsnano. 9b08984(about DOIs).

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