Reduction of methanol formation during alcoholic fermentation

Pieper, H. J.; Oplustil, E.; Barth, Gerold

doi:10.1007/bf00144243

“…There is a clear indication from several studies of an up to 50% reduction in methanol by acidification of fruit mashes [ 4 , 22 , 25 , 26 , 33 , 34 , 35 ].…”

Section: Factors Influencing the Methanol Content Of Fruit Spiritsmentioning

confidence: 99%

“…There is not a clear preference about the kind of acid to be used. Gössinger et al suggest ortho-phosphoric acid (85%) [ 26 , 53 ] while Pieper et al suggested sulfuric acid [ 35 ]. Commercially available products for acidification often contain mixtures of several acids such as malic acid/hydroxypropionic acid or phosphoric acid/lactic acid.…”

Section: Factors Influencing the Methanol Content Of Fruit Spiritsmentioning

confidence: 99%

“…The effectiveness of lyase enzymes can be increased by dilution of the mashes with water [ 26 ]. Similarly, the addition of certain detergents (anionic surfactants) as well as polyphenols (tannins) has a reducing effect on the release of methanol by full or partial inhibition of pectin methylesterases [ 19 , 34 , 35 , 41 ]. However, a large amount of agents is needed, which are rather expensive so that these methods were not widely implemented in practice [ 39 ].…”

Section: Factors Influencing the Methanol Content Of Fruit Spiritsmentioning

confidence: 99%

See 1 more Smart Citation

Methanol Mitigation during Manufacturing of Fruit Spirits with Special Consideration of Novel Coffee Cherry Spirits

Blumenthal

¹

,

Steger²,

Einfalt

³

et al. 2021

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Methanol is a natural ingredient with major occurrence in fruit spirits, such as apple, pear, plum or cherry spirits, but also in spirits made from coffee pulp. The compound is formed during fermentation and the following mash storage by enzymatic hydrolysis of naturally present pectins. Methanol is toxic above certain threshold levels and legal limits have been set in most jurisdictions. Therefore, the methanol content needs to be mitigated and its level must be controlled. This article will review the several factors that influence the methanol content including the pH value of the mash, the addition of various yeast and enzyme preparations, fermentation temperature, mash storage, and most importantly the raw material quality and hygiene. From all these mitigation possibilities, lowering the pH value and the use of cultured yeasts when mashing fruit substances is already common as best practice today. Also a controlled yeast fermentation at acidic pH facilitates not only reduced methanol formation, but ultimately also leads to quality benefits of the distillate. Special care has to be observed in the case of spirits made from coffee by-products which are prone to spoilage with very high methanol contents reported in past studies.

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“…There is a clear indication from several studies of an up to 50% reduction in methanol by acidification of fruit mashes [4, 22,25,26,[33][34][35].…”

Section: Inhibition Of Pectin Methylesterase By Acidification Of Mashmentioning

confidence: 99%

Methanol Mitigation During Manufacturing of Fruit Spirits With Special Consideration of Novel Coffee Cherry Spirits

Blumenthal¹,

Steger²,

Einfalt³

et al. 2021

Preprint

View full text Add to dashboard Cite

Methanol is a natural ingredient with major occurrence in fruit spirits, such as apple, pear, plum or cherry spirits, but also in spirits made from coffee pulp. The compound is formed during fermentation and the following mash storage by enzymatic hydrolysis of naturally present pectins. Methanol is toxic above certain threshold levels and legal limits have been set in most jurisdictions. Therefore, the methanol content needs to be mitigated and its level must be controlled. This article will review the several factors that influence the methanol content including the pH value of the mash, the addition of various yeast and enzyme preparations, fermentation temperature, mash storage, and most importantly the raw material quality and hygiene. From all these mitigation possibilities, lowering the pH value and the use of cultured yeasts when mashing fruit substances is already common as best practice today. Also a controlled yeast fermentation at acidic pH facilitates not only reduced methanol formation, but ultimately also leads to quality benefits of the distillate. Special care has to be observed in the case of spirits made from coffee by-products which are prone to spoilage with very high methanol contents reported in past studies.

show abstract

“…Crowell and Guymon (1973) analyzed the aroma constituents of plum brandy produced in California, but there were no methanol data. Pieper and others (1980) investigated the effect of acidification of mash on the reduction of methanol in plum, cherry, and pear wines. Nikićević and Tesevic (2005) studied the influence of plum must pH, alcohol fermentation causing agent, fermented must storage time, and distillation method on the methanol content of plum brandy.…”

Section: Introductionmentioning

confidence: 99%