Fishy Smell in a Muscat / 71B

If my memory serves me correctly 71B has the ability to metabolise malic acid to lactic acid. This would raise the pH. Muscat, particularly warm climate can have high pH which favours bacteria. Have you added SO2.I would add 50ppm straight away to start with. Check the pH, I bet it is about 4. Add a lot of acid if it is 4, like 5 grams per litre. Then chill to drop out the acid as bitatrate and get the acidity to an aceptable level, the add some sugar prior to bottling to balance the acidity, and sterile filter if possible though 0.45um membrane on the way to the bottle to make sure it is sterile and yeast free. Add 200ppm sorbate as well.

Not sure if this will work to clean it up, but I suspect that your story is a good example of the importance of checking pH of the juice and wine, and always adjust early.

Bacterial are every where, from the air, to your large intestine, and your nasal passages. Low pH in wine is bad for them, they do not like pH's less than 3.5.

Good Luck,

James.

Thanks James-

They started out just fine and have been under airlock since- wrapped in a blanket.

It's odd I santized all the gear first and ONLY the muscats are showing this problem- both the 71B and the Cote de Blanc. I'm wondering if it's a bad batch. Everything else is fine (including the EC118 I purchased a week earlier).

I brought the SO2 up to 60ppm and I'll do the pH tommorow.

Jas> snipped-for-privacy@gmail.com wrote:

Checked the pH twice this morning. Both Muscats come in at 3.0- and I verified the settings against 2 control solutions (7.01 and 4.01). So unless my probe is giving me problems I'm going to have to look elsewhere.

For whatever reason I always seem to have low pH wines. They come up with time, but for a long while they like to mock me down in the 2.9 to

3.2 range.

Jas> snipped-for-privacy@gmail.com wrote:

Jason, Sounds weird. I think that acid can be formed from malolactic fermentation but at a pH that low it sounds like that might not be it.

71B does metabolize some malic but I use it on almost all my northern whites and never saw this. That it _tastes_ like fish is odd. I'm not sure this is an excess butyric acid issue. See if this link helps at all:

You can email Clayton Cone of Lallamand regarding 71B and this issue; he is a Lalvin yeast expert

Joe

Thanks Joe.

Tastes Wierd too ;) When I say fishy- I don't mean fish-mongrel-meat-market fishy. I mean cooked cod smell. Hence my really really confused state.

Could be a little H2S in there too.

I have 3 muscats going. 1 with EC118 (rather nice but lacking flavour) and purchased a week prior to the other two. The two additional ones I bought to experiment with- and both have that cooked- cod aftertaste. Maybe it was on the lees too long- I guess I have quite a bit to experiment with now.

If you want a taste I'll save you a vial ;)

I'll email Clayton after the holiday.

Jas> Jason,

I use 71B a lot and it's actually better at preserving or creating fruitiness; it could be it was on the lees too long.

Joe

Anything to take care of awine that was on the lees too long? I racked the first time after 3 weeks when it had finally dropped/clear...

Jas> > I have 3 muscats going. 1 with EC118 (rather nice but lacking flavour)

3 weeks is not a long time, but Margalit tells you how to deal with hydrogen sulfide and mercaptans pretty well. I'm pretty sure if you Google mercaptan in the archives you will find the process; one of us had to post it at some point. I can again if it's not there. You do a small scale test with glasses of wine and ascorbic acid and copper sulfite, if the smell goes away you know what to do.

Joe

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