Slow Fermentation - should I be worried?

[Wiccan_Lager]

Hey everyone,

about a week ago I purchased a few pales of Sangiovese, Alicante and Zinfandel. All of them had a OG of around 1.090. I pitch the yeast and in three days the SG dropped down to 1.005ish on all of them. Fast if I may say so.

But last Sunday I picked up a 6 gallon pale of Grenache (rose' to my demise) and pitched my yeast on Monday morning. The juice temp was about 70 degrees (just as the others were). The OG of the Grenache was about 1.085 if I recall correctly. Yesterday I went to stir up my bucket and test my SG and the hydrometer dropped to about 1.080.

I know it can't be the temperature seeing as it has been constant through out. The yeast seems to be working. The Grenache has a white foam on top. Could this be bad yeast? Is this something typical of rose'? Or does something like this normal? I have never seen wine ferment this slowly.

Oh, and the yeast I am using is Lalvin ICV-GRE.

If you guys need more info let me know. And if I over reacting let me know too. I tend to be paranoid.

 

[Turock]

Are you using yeast nutrient? Lack of nutrient is the biggest reason for sluggish ferments. No matter what culture you use---you should always split the nutrient dose into 3 batches to pitch thruout the ferment. You don't want yeast to become stressed because they produce more H2S when stressed and the ferments slow way down and can stop because the yeast can't reproduce properly.

 

[Wiccan_Lager]

Good idea. I never used yeast nutrient before. Tomorrow I took off form work. I will take a ride to the local homebrew shop and pick some up.

Thanks!

 

[wineforfun]

Turock,
So if a recipe calls for 2tsp. nutrient, you are saying it shouldn't all go in at once? Is the splitting up of the nutrient a "trick of the trade" as most recipes (at least the ones I have seen) don't talk of splitting it up.
Also, is it possible to put too much nutrient in?

 

[Wiccan_Lager]

Hello gentlemen,

Well as it turned out I over reacted. And so did the yeast. Last night there was a little bit of activity. Tonight I went down there to stir and holy crap. I took a SG reading and the SG plummeted to below 1.000.

Sneaky little bastards...

 

[Turock]

winefor fun---Yep, that's right. Splitting the nutrient batch is something you learn about when you start doing more studying with the lab sites like Scott and Lallemand and also studying the catalogs from the wine suppliers. I have a love for learning things in depth--so I'm always studying things. I run across alot of techniques this way, and always try to tell others what I've discovered. But nothing replaces your own course of study. You can become very knowledgeable by taking yourself to school.

 

[Turock]

Don't overdose nutrient--use the recommended dose. You shouldn't be adding more nutrient once you get past the 50% dry stage because the yeast can't utilize it and it makes a good environment for spoilage organisms like Brett to make use of.

 

[Floandgary]

Looks like this might be the place to get a helpful suggestion. I have a bucket of Mosto Bello Vermentino and a bucket of Mosto Bello Pinot Grigio fermenting for nearly 2 weeks now. I know that whites are a little slower than reds, but they seem to have trouble getting below 1.030 SG. Temp is @68-73F and I even put a heater on Vermentino for a couple of days. Might they need some help or will another week be necessary? They get a good stir daily.