Mold During Primary

[weston08]

I've never played around with yeast strains that much in my 6 years of making wine. To try to get a better understanding of different types of yeast I followed the EC Kraus recipe for 5 gallons of apple wine, four different times. Each 5 gallons I used a different yeast: Montrachet, D47, EC-1118, & Pasteur Champagne. It has been cool to see the yeast strains all acting different during the primary fermentation. The biggest difference I noticed was that the D47 had a crust on top with a lot of small mold spots all over it... I was able to carefully remove the crust/mold and I transferred the must into the secondary while leaving a lot of the suspect juice in the primary. It is now bubbling in the secondary.

Has anybody experienced mold like this before? Do you think it's fine to continue with this batch? I was hoping to learn more about yeast strains than about mold but I guess knowledge is knowledge. Any input is greatly appreciated!

 

[VinesnBines]

That doesn't look like mold. Looks like krausen that develops when the yeast is working. Since this is apple, it appears to be acting like fermentation of cider. Are you stirring the must?

 

[weston08]

Yes I do think it is krausen since I have not stirred it. I usually do with my own recipes, but the recipe I followed did not indicate to do so and I was trying to keep everything as constant as possible. Stirring may have been the biggest thing that I've learned about with this experiment. I've always wondered if it really mattered since there are so many recipes that do not call for it, but I've never wanted to find out bad enough.

I attached another image with my cameras flash on which makes what I believe to be mold stick out more.

 

[VinesnBines]

I think you should be fine. The higher alcohol of wine should wipe out any bugs or mold. Stirring keeps that krausen moist and prevents mold. When making beer we keep the oxygen out to prevent mold.

 

[weston08]

For this recipe, while in the primary, the must is simply covered with a towel since it gasses off so much. Once it goes into the secondary an air lock is required to keep the oxygen out.

Do you think I will need to do anything special to this batch or should I just carry on like normal?

 

[Rice_Guy]

Mold requires oxygen for growth, remove oxygen and it will die off (if mold).

curious if your apple was a fresh non pasteurized higher solids cider

 

[weston08]

We pressed fresh Northern Spies directly into the primary fermentation tanks. There was no extra filtration or anything.

 

[KCCam]

My understanding is that one of the reasons for punching the cap of fermenting grapes down is to prevent mold from growing. Yes, mold needs oxygen, but so does yeast during primary, doesn’t it? Whether a recipe calls for it or not, I think daily stirring would be beneficial.

 

[Rice_Guy]

Yeast need oxygen for building up a cell population, to translate that into wine talk we start with one packet or a billion yeast cells and 1.090 sugar, there is enough oxygen in surface air for a six gallon primary for normal yeast growth,, when the sugar is down to 1.050 there are plenty of cells to finish consuming sugar ,, and if the gravity is down to 1.010 yeast are on decline so we shouldn’t add oxygen or do a daily stir.

My understanding is that one of the reasons for punching the cap of fermenting grapes down is to prevent mold from growing. Yes, mold needs oxygen, but so does yeast during primary, doesn’t it? Whether a recipe calls for it or not, I think daily stirring would be beneficial.

note: if I am running a 1000 gallon cell culture reactor there isn’t enough surface mixing so we sparge oxygen into the tank but the need for extra oxygen still follows the gravity

 

[cooknhogz]

Doesn’t look like mold to me and I currently have 45 gallons going. Next time try Red Star Cote Des Blanc or Fermentis SafCider for your Apple wine / Cider and I stir my apple wine / Ciders twice a day for at least the first 3 Days.

 

[stickman]

Open fermentation with a crust of yeast and pulp etc., it most likely is mold....sure looks like it to me. The wine has been moved to a closed vessel so everything should be fine.

 

[cooknhogz]

Stickman your right, I looked at it again (with my glasses on) and I do see little spots of mold. I do all my ciders, and I do a lot, with only fresh apple cider and luckily I have never experienced mold in the primary. I stir the first two to three days and at the end of the first week all my apple and grapple ciders were at 1.000 and racked to secondary.

 

[weston08]

Thanks for all your replies! This batch seems to be going strong in the secondary (which hopefully will take care of everything). Time will tell, but due to your posts, I'm glad I didn't dump this batch! It's been very interesting to see all the differences between the yeast strains; color, activity, amount of foam, and in the case of the D47 - krausen that lead to some mold. I'm definitively learning a lot from the experiment and am glad that I decided to do it. I'm especially excited for the taste testing later on! Hopefully some of these will turn out well. I've always used typical cider yeast such as Brewers Best, Safcider, and Lalvin EC-1118. Who knows, maybe I'll find a new go to cider yeast from this experiment!