Question via Twitter

[John McIlwain]

Posed by Sarah Chappell (Vine Wines buyer) on Twitter:
"Noob question: can a spirit have VA?"

Anyone?

 

[Unknown]

nope. only a ghost.

or a shaman.

fb

 

[Florida Jim]

That would be an evil spirit.
Actually, I have seen people use vodka around barrel bungs to keep bacteria laden fruit flies away. The bacteria they carry can cause VA.
Best, Jim

 

[Greg Hirson]

Sure. If the underlying product has high VA, the acetic acid can distill over. Usually the distiller would try to avoid that outcome. If I remember correctly it comes over later than the less polar compounds during distillation but is hard to cut out all together.

 

[MLipton]

originally posted by Greg Hirson:
Sure. If the underlying product has high VA, the acetic acid can distill over. Usually the distiller would try to avoid that outcome. If I remember correctly it comes over later than the less polar compounds during distillation but is hard to cut out all together.

The boiling point of acetic acid is 116°C, which is well above the boiling point of the ethanol/water azeotrope (78°C). There is no earthly reason why any distilled spirit should also contain acetic acid if the distiller is at all competent at the job.

Mark Lipton

 

[Arjun Mendiratta]

True, but ethyl acetate boils at 77.1.

 

[Greg Hirson]

originally posted by MLipton:

originally posted by Greg Hirson:
Sure. If the underlying product has high VA, the acetic acid can distill over. Usually the distiller would try to avoid that outcome. If I remember correctly it comes over later than the less polar compounds during distillation but is hard to cut out all together.

The boiling point of acetic acid is 116°C, which is well above the boiling point of the ethanol/water azeotrope (78°C). There is no earthly reason why any distilled spirit should also contain acetic acid if the distiller is at all competent at the job.

Mark Lipton

I agree, it shouldn't be there. Acetic acid need not reach it's boiling point for it to partially distill over. A poor tails cut will do it. Looking at the Twitter message referenced, the aroma that she noticed was more ethyl acetate (described as nail polish remover) which would distill early.

 

[SFJoe]

originally posted by Arjun Mendiratta:
True, but ethyl acetate boils at 77.1.

This would be the pesky part.

 

[MLipton]

originally posted by SFJoe:

originally posted by Arjun Mendiratta:
True, but ethyl acetate boils at 77.1.

This would be the pesky part.

Whether EtOAc qualifies as VA is, I think, a subjective call. To me, it smells of overripe peaches. Others of my acquaintance get a much sharper smell, which I attribute to hydrolysis in the nasal mucosa.

Just a guess,
Mark Lipton

 

[Arjun Mendiratta]

Regardless, any mixture of ethanol and acetic acid will contain some amount of ethyl acetate, which means that our perception of wines marked by VA will always be colored by the presence of ethyl acetate

 

[Marc D]

The WD Chemistry welcome wagon for Greg, good work guys!

 

[MLipton]

originally posted by Marc D:
The WD Chemistry welcome wagon for Greg, good work guys!

Since Greg was a Chem major at Berkeley, I feel it only appropriate that the Welcome Wagon take that form.

Mark Lipton

(UCB postdoc '88-'90)

 

[Greg Hirson]

such a warm welcome!

 

[Everett Bandman]

originally posted by MLipton:

originally posted by Marc D:
The WD Chemistry welcome wagon for Greg, good work guys!

Since Greg was a Chem major at Berkeley, I feel it only appropriate that the Welcome Wagon take that form.

Mark Lipton

(UCB postdoc '88-'90)

Youngin!

Everett Bandman
(UCB postdoc '76-'78)

 

[MLipton]

originally posted by Everett Bandman:

Everett Bandman
(UCB postdoc '76-'78)

Molecular biology, Everett? Bruce Ames was just on campus giving a talk last week and he's still looking amazingly youthful. I attribute it to all the mutagens in his diet.

Mark Lipton

 

[Everett Bandman]

originally posted by MLipton:

originally posted by Everett Bandman:

Everett Bandman
(UCB postdoc '76-'78)

Molecular biology, Everett? Bruce Ames was just on campus giving a talk last week and he's still looking amazingly youthful. I attribute it to all the mutagens in his diet.

Mark Lipton

Ph.D. was in Molecular Biology in '74. Did a post-doc in Zoology from 76-78 with Dick Strohman. Stayed in Zoology dept until 82 running Dick's lab for him while he was off being a Dean until I got my faculty position at Davis. Bruce is a fun guy to listen too. I retired in 2005 and glad to have done that. Don't miss science at all these days.