PDA

View Full Version : Dry re-pitching 71B



NvrWrkn
12-28-2007, 07:26 PM
Howdy! :wave:

I have a 7 day old 71B ferment going very slowly. Specs are as follows:

GoFermed 2 packs, must diluted down to 80
SG in 8 gallons must 1.080 at 72
24 Hrs after pitch added 6gms DAP and 6gms FermaidK
Temp during last 7 days = 68
After 7 days SG = 1.070

Fermenting in 15 gallon plastic barrel, lever locked with airlock. After 7 days I was looking for more airlock activity but it appears slow and steady. Checked SG and noticed .010 drop in 7 days. I thought 71B was supposed to be a moderate fermentor and had low nutrient requirements. I feel the SG drop is showing me a slow ferment. Also, when I pulled the SS paddle I stir with out of the must it seems there's very little yeast stuck to the blade compared to previous ferments where after 7 days I would see much more.

It seems as though the yeast didn't reproduce as well as expected. So, I aerated the must vigorously for several minutes today and just dry pitched another 71B pack.

Any opinions on whether that was a waste of time?

liff
12-28-2007, 09:37 PM
Well, I don't think the dry repitch could hurt.

How exactly did you rehydrate the initial yeast? You may have damaged or impared them somehow. Other than that, I have no ideas.

NvrWrkn
12-28-2007, 11:28 PM
did the usual 104 with bottled water, added the goferm, stirred, added the yeast. Let it sit for 15 or so then started adding some must every couple mins to bring the temp down to 80. When the 30 min mark came I pitched into 72 degree must at 3.2 pH. I can't imagine an 8 degree diff would shock this yeast. I didn't run the full nutrient regimen either since this strain doesn't need a lot. So if I didn't temp shock it, and likely didn't nutrient shock it, the only other thing I can think of is a low fertility batch. I got it from Midwest.

I've never dry pitched into a mead must with nutrient already in it so I was looking to see if anyone has ever done it before and has data on whether it went active or just locked up.

Never used 71B before, and it's not looking good for a rematch! Maybe a gallon show one more time to see if it was the water or something.

Just checked pH again, 3.1.

liff
12-29-2007, 06:24 AM
It seems to me that it is just a bad packet. You did what you are supposed to do.

IIRC, none of the wine kits recommend rehydrating the yeast. They just say to dump in the yeast by sprinkleing the yeast on top. With this must, I don't think it could hurt. The question still would be, why not try to rehydrate again?

Johnnybladers
12-29-2007, 11:35 AM
Might Ph. be the problem? 3.1 seems kinda low, isn't 3.5 considered ideal?

NvrWrkn
12-29-2007, 07:27 PM
Rehydrating would have been the best thing for repitching although I didn't want to add any more goferm to a lazy ferment fearing a taste change. I'm getting lazy with age too. I decided to insulate the barrel and keep the room temp at 72, I'm getting better activity now. Being 24 hours or so I can't be sure if it's mostly due to temp or repitch.

I guess from now on I'm going to start my ferments around 72 to 74 until I see good activity, then lower the temp down to mid 60's for full ferment. That plus stick with yeasts I have better historical data on.

3.1 is a tad below ideal, but not low enough to cause fermentation problems. With the clover I use for most melomels I'm always right there at 3.1 - 3.2 and things usually go fine.

I still have a few packs of 71B left, I think I'm gonna experiment with a small batch in a gallon jug and watch the dynamics. You never know what happened to the yeast before you get it, I wouldn't think Midwest mishandles their yeast. Maybe a bad packet.