RP-!5 Rockpile Yeast

[cuz]

I pitched 3 buckets of juice - Zinfandel, Malbec, Merlot. The Zin got RP-15 the others got RC 212, all got hydrated with goferm. I read that the RP-15 was a slow fermenter but now I am getting concerned. It's only been 48 hours but the Malbec and Merlot are bubbling over and the Zin seems very quiet. I am debating on adding Fermaid O now and then again later but don't know if that's too much. Maybe half now and half later. Hopefully it doesn't get stuck.

Has anyone used the RP- 15 before? Should I be concerned or does it just take longer to ferment?

 

[Jovimaple]

What was the starting s.g. and what is the s.g. now? That's the most accurate way to tell if fermentation has begun.

I did a couple of kits where there didn't appear to be much action but my hydrometer showed fermentation was occurring just fine. (Not sure what kind of yeast came in those kits.)

 

[winemaker81]

I agree with @Jovimaple, use your hydrometer to check.

How long did you rehydrate the yeast? I've taken a tip from Finer Wine Kits and am letting the yeast rehydrate overnight, at least 12 hours. [They recommend 18-24 hours.] This gives the yeast a chance to build a larger colony. Also, FWK recommends gently pouring the starter down the side of the fermenter so the yeast does not spread as much. It apparently reproduces faster when the colony is more densely clustered.

 

[Chuck E]

I've used RP-15. According to my notes, it started slow and finished well. I also stirred the ferment at least once a day.

 

[cuz]

It's starting to kick in now. Going to add nutrients. I have always hydrated for 30 minutes but I will try overnight next time around