Methanol Detection

Quality & Safety for distillers

Distilling spirits is a traditional business and is often based on knowledge passed down over generations. With great dedication, noble brandies with a unique variety of aromas are produced.This dedication already begins with the selection of the fruit and the careful supervision of the fermentation of the mash. The experience of the master distiller, as well as his fine sense of smell and taste are put to the test especially during distillation, where it is necessary to separate the alcohol as well as the aromas from the impurities in the pre-run and post-run.

The subsequent maturation of the distillate in the barrel must also be constantly monitored. It is like an art when the results reflect the quality of the fruit, the soil and the region - and are elegantly rounded off in the wooden barrel at the end.

In addition to the highest quality, safety plays a major role in the distillation process. During fermentation, harmful methanol can be produced, which can reach dangerous concentrations during distillation. For this reason, there are strict limits for methanol in Switzerland and the EU. Depending on the type of alcohol and the underlying fruit, these range from 1,500 g/hL to 5 g/hL per

pure ethanol.

Contrary to popular belief, the human nose cannot distinguish methanol from drinking alcohol (ethanol). Therefore, even spirits produced under professional conditions often exceed the limit value. An investigation by the European Commission, in which 183 commercially available Williams pear spirits from Germany, France, Italy, Switzerland and Luxembourg were tested for their me-thanol concentration, revealed methanol values of up to 1,865 g/hL, which clearly exceeds the legal limit.1

How can the methanol content bedetermined?

Up to now, methanol measurement has primarily been carried out using gas chromatography (GC) or liquid chromatography. However, these methods are not profitable for many distilleries, as they are usually carried out via laboratories and thus cause high costs

and time expenditure. In practice, this means that many distillers do not measure the methanol content of their products, or do so only irregularly, and thus have no knowledge of whether they are complying with the legal requirements.

Recently, the first pocket-sized mobile laboratory has become available: With the Spark M-20 it is possible to measure methanol in alcoholic beverages even by laymen in less than 2 minutes. The Spark M-20 was developed in Switzerland and is produced in Germany. It therefore meets the highest quality standards. With the help of the device, an immediate quality control can be carried out on site - thanks to automatic temperature control both during distillation in the cellar and outdoors.

The Spark M-20 can be used for all beverages, e.g. fruit brandies, grappa, whisky, gin, calvados, brandy, sherry or cognac. Up to 1'000 measurement results can be stored on the instrument and transferred to the PC. The Spark M20 was developed in close cooperation

with important representatives of the industry, such as the state institution Agroscope or the renowned Swiss distilleries "S. Fassbind AG" and "Z'GRAGGEN DISTILLERIE AG".

"We are pleased to integrate the Spark M-20 into our quality management system. For the first time, methanol in spirits can be

quantified quickly and efficiently," explains Daniel Z'graggen, Managing Director of Z'GRAGGEN DISTILLERIE AG.

How accurate is the measurement?

To validate the measurement accuracy, tests and interlaboratory comparisons were carried out with the Spark M-20 by various independent institutions.

DistiSuisse

DistiSuisse's award-winning spirits were tested for their methanol content using 14 samples. To prove the accuracy of the instrument, the results were compared with reference values for methanol content from METAS (Swiss Federal Institute of Metrology). The spirits

used ranged from fruit spirits, whisky, gin, vodka to exotic variants such as ran-den schnapps, with different methanol as well as ethanol concentrations.

The Spark M-20 successfully determines the methanol concentration in all cases, regardless of the type of spirits and their ethanol content. The deviation from the reference method was 3 ± 6 %.

Interlaboratory test

In an extensive round robin test, in which more than 10 distilleries, reference laboratories and research institutes participated, 4 samples each with known composition were measured. All samples were analyzed under the same conditions, for accuracy estimation according to ISO 5752.

The deviations in repeatability were <4% (or 0.01 vol%), in reproducibility <6% (or 0.01 vol%), and in trueness <5% (or 0.01

vol%) of the measured value

Examination by German customs

The German customs authorities also tested the methanol detector with regard to measuring accuracy and practical suitability for distilleries and came to the following conclusion: "The device is well suited for practical operation in fruit distilleries.