Moldy Sirah grape

[MarsColonist]

The local wine guild got our wine grape from California Monday nite. At the crush, the Sirah came in substantially moldy (white mold... not my grape, but looked like the attached pic). We picked through the grape and pulled the parts that looked the worst (pulled 3/4 lug from 5 ... ~15% loss). Looks like it was raining in California and the mold developed in transit (Suisun valley, CA to Austin, TX). The ripest grapes were the ones most affected.

At crush, Brix was 22.5 and pH was 3.8-3.9. I added 90ppm via 10% Kmeta solution. I have no idea of the TA. The must tasted fine (but then again, Im fairly new at tasting fresh vinifera grape).

Last night I added about 4.5g/L of tartaric acid to fix the pH (down to 3.23 this morning), French Oak chips, VR Supra tannin, OptiRed, Lallzyme and some pectinase. Everything is sitting <60°F. Ill aerate, add nutrients and yeast (RP15) tonite.

Anyone have any other info I should consider?

 

[robie]

Too bad about the mold. Good luck on your wine making.

The TA should drop a little and the PH rise some during alcohol fermentation. That should leave you about right.

Do you intend to do an mlf?

From what distributor or farm in California did you get your grapes?

 

[MarsColonist]

The Malbec was a little moldy, but not nearly as bad as the Sirah. The Cab Sauv, Sangiovese and Zin were fine. This is only my second year to get grape though the Guild, and this is first time out of the last six or so years they have had a problem of this magnitude with the grape .

Im hesitant to name vineyards on public forums, but it was from Suisun Valley, Ca. PM and Ill tell you.

Well, with 90ppm of SO2, I gather that might be hard to get MLF to start, even though its my understanding that the vast majority of the SO2 will be bound or driven off by the end of primary fermentation. I suppose I would like to, but dont fully understand the requirements other than pH needs to be >3.1 and SO2 < 10ppm, nor do I fully understand the mechanics of SO2 binding and utility during primary fermentation.

Further: the picture above says (now that I translated it) this is mold development after two months in cold storage!!! Damn, I had whole clusters that were too inundated to use..... Either it set fast in transit, or they werent picked in the last week...

 

[robie]

Well, with 90ppm of SO2, I gather that might be hard to get MLF to start, even though its my understanding that the vast majority of the SO2 will be bound or driven off by the end of primary fermentation. I suppose I would like to, but dont fully understand the requirements other than pH needs to be >3.1 and SO2 < 10ppm, nor do I fully understand the mechanics of SO2 binding and utility during primary fermentation.

That's why I had asked; that is pretty high. I read where up to a certain point, 50% of the SO2 will become immediately bound. Over that point the % immediately bound drops. Based on that, your's should come out of alcohol fermentation at about 45.

At the end of alcohol fermentation you could check free SO2 level and maybe do an mlf. Viniflora CH35 is an mlb that can take much higher SO2 levels (50ppm), as well as very low ph (PH < 3.0). Check it out at
http://www.menasa.es/marcas/lamothe/BACTERIAS/bacteria%20ch%2035.pdf

It can be ordered from several places on the internet. Now it is designed for whites and roses, but I don't see why it wouldn't work for your red. So, if you do want to do an mlf, I would certainly try it.

Good luck.

 

[Wade E]

Bummer about the mold. I was supposed to get some Chilean grapes this year but the whole shipment was denied by the retailer due to this very same thing. After fermentation is complete you should be fine to do MLF. If your worried about sulfites still being high there are a few mlf strains that can handle up to around 550 ppm and thats way higher then where youll be. morewine.com is a good supplier of stuff like this.

 

[ibglowin]

Just PM'd you.......