An 'acetone' smell in my experience is consistent with ethyl acetate, a
reaction between acetic acid and ethanol. An acetobacter infected
barrel can result in ethyl acetate in the wine.

As discussed by others' responses, ozone will reduce acetobacter in a
barrel. Whether or not it can eliminate it depends on how deep into the
oak the acetobacter has penetrated. If it is surface or near-surface,
ozone is very effective at killing the acetobacter.

Ozone 'eats' (oxizides) the wood as well as killing bacteria, so it gets
used up. This limits the efficiency of ozone for killing deeply
penetrated acetobactor infection.

So it is worth a try to use ozone (via ozonated water spray) to see if
it 'recovers' your barrel. It will likely work, but may not in all cases.

I've used ozonated water in industrial applications as well as for
washing wine barrels. In addition to being a strong
sanitizer/disinfectant, ozone is very aggressive at degrading plastics
and rubber via attacking the carbon-carbon double bonds. It also slowly
oxidizes cellulosic materials like oak. Ozone is a double-edged sword.

Gene

Lee wrote:
> I usually make red wine in 6-8 gallon batches, always from grapes.
> About 3-4 years ago, I started aging in small french oak barrels,
> initially with really good results. But lately, I'm getting a
> definite acetone smell in my reds, especially the cabs and nebbiolos.
> I think I'm coming to the same conclusion that I've read in lots of
> places...that "small barrels are like wooden sailboats...the idea
> sounds great, but in practice they're more trouble than they're
> worth". Usually, I just empty one barrel, wash it out with hot water,
> then re-fill with another wine.
>
> I have a couple of questions:
> 1. Once you have a problem with volatile acidity in a barrel, is
> there any recourse other than to throw away the barrel?
>
> 2. When you empty your barrels, if you don't have another wine ready
> to put right back in the emptied barrel, what do you put in it?
>
> 3. If I wanted to treat my barrels with something, what would you
> use?
>
> 4. What is your experience with small barrels?
>
> Thanks,
>
> Lee