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**fatbloke** · 17-10-2009, 04:41 PM

Here's their yeast spec' chart

It says about the temperature being 20 to 30, but some other stuff might be relevant as well.

3.3 is a little on the acid side, I'd have thought, but I don't see why it might really cause much of a problem.

It does point out about the relative nitrogen needs being high though and that it's only a moderate (speed-wise) fermenter.......

regards

jtfb

**P cuthbert** · 17-10-2009, 05:23 PM

Chris;

You seem concerned about the acid levels in this wine. Perhaps a bit high, but not really unreasonably so.

I would consider inoculating with a ML bacteria at this time. This will reduce the malic acid, reducing acid, increasing the pH and softening the wine.

As for the apparent "stall", it may be a matter of temperature, a matter of dissolved solids, or the natural slowing as the fermentation nears completion.

A splash rack from one carbouy to another will incorporate some oxygen to assist in the final fermentation of this wine, and will release any H2S that may be developing.

Your use of the hydrometer may also be somewhat incorrect, causing a "false" reading.

Do you degas your sample before testing? Do you twirl the hydrometer as you put it into the wine? Do you take your reading quickly once the hydrometer is in the wine? Do you read the hydrometer at the level of the wine? or the meniscus where the wine creeps up the hydrometer?

Degassing will remove the CO2 that tends to collect on the hydrometer lifting it slightly, showing a higher density. Twirling the hydrometer and reading it as soon as it stabilizes will also prevent dissolved gases from collecting on the hydrometer. Reading the hydrometer at the meniscus is easier than reading it at the level of the wine, but will result in an incorrect reading. If you wish to read the meniscus, then apply a "fudge factor" of -.002 to -.004 to the reading you have.

Taking this into account, your reading of 1.000 may actually be in the range that you are looking for.

You may also wish to obtain a close range hydrometer for the final readings. The spacing on these is much wider than on the standard wine making hydrometer. This will give you much more accurate readings as the fermentation completes. Look for one in the range of +5 to -5 brix.

Hope this all helps;

Pat

**rjb222** · 17-10-2009, 05:54 PM

I agree Pat the hydrometer reading could easily be off from the solids floating around from the grapes.The time line is about right to be finished ferment and the wine should be going into a clearing or settling out time.If there is a light ring of bubbles around the top edge of the wine then there is likely still a small amount of fermentation going on. This is where I prefer the triple bubble type air lock to the three piece. The triple bubble will show you if any gas is escaping at all if it is pushed up into the release chamber side.With the tree piece it is sme times very hard to tell as the lock does not get enough pressure sometimes to lift.

**chris_b** · 18-10-2009, 07:54 PM

Thanks for your replies everyone,

@JtFB: thanks for the link to the data, I'd not seen that before - esp the high temperature range, and if I had I'd probably have chosen a different yeast. I've used Gervin GV2 for my reds in the past (blackberry etc) and it's always worked fine giving me finished SG 990 to 995, so perhaps I should go back to what I know. Think I chose Lalvin as the supplier I was buying from didn't have any Gervin at the time

@Pat/rjb22: I'd thought about trying a ML so I'll give it a try in due course. There's lots of stuff about it on this forum so time for a good read before I commit. Also seems I should wait for the primary fermentation to stop (though I'm trying to encourage it not to do so at the moment)

I was pretty sure the hydrometer reading was ok - but I will check again. I do read from the level of the wine, but don't take any particular precautions about bubbles. I'll look for a close range gadget as well.

Before I posted I'd given it a good airborne racking and dosed with a bit more nutrient. Today there are some signs of life as the airlocks turned over a couple of times, the temperature in the room was probably falling at the time so hopefully this is action not thermal expansion.

Chris

**lockwood1956** · 18-10-2009, 08:51 PM

The Lalvin RC-212 and the Gervin GV2 I believe are the same yeast........

**lockwood1956** · 18-10-2009, 08:53 PM

Lalvin RC212 (Bourgovin) : This yeast is traditionally used in the Burgundy region for full red wines .

Gervin Yeast - No. 2 : Red Label, Full bodied red table Burgundy/Champagne

**chris_b** · 22-10-2009, 09:21 PM

Been away a bit.... Interesting thought, Bob. I can't find any horse's-mouth data on Gervin yeasts on the web - no sign of a Gervin website, only the phone number on the label so perhaps I'll give them a ring. Several places (who may simply be propagating the same myth) seem to distinguish the two on the basis of temperature (Gervin no 2 is "ok" to 15C, Lalvin RC212 is rated for 20 - 30C), and mention that RC212 needs a lot of assimilable nitrogen but without details in gms/litre or anything so useful. Btw I detected a slight sulphurous odour when doing the shaking so perhaps it's all down to the RC212 appetite for N, I added some more at the time

Anyway, a week after I gave it a good splashy pouring, one carboy is fermenting slowly but surely and the other is quiet. Is there any merit in moving some juice/lees from the active one into the quiet one, on the basis that the yeast is active and alcohol-aware? Or should I just go into unstick-mode, get some EC-1118 and follow the stuck ferment guide

in Tutorials? don't want to disturb the working one if it's not worth it....

Following the remarks about bubbles on hydrometers, I took another sample and shook it a lot (much frothing) then measured several times quickly and with much twirling of hydrometers. I think that won me a little - say to 0.998

Chris

**ukric** · 22-10-2009, 09:25 PM

Gervin yeasts

Page not found - Muntons

http://www.muntons.com/homebeer/other-products/gervin-yeast.asp

**chris_b** · 16-12-2009, 10:46 PM

Update 5 weeks on ....

After the big shake and addition of further nutrient, there was a short pause then the airlocks on both B-bottles have been turning over very slowly but continuously for about a month, then stopped. I measured the gravity on 2 Dec (lots of shaking to degass and debubble first as advised above): in bottle A it was 995, bottle B was 996. That's good enough for me - I tasted both brews and don't find either to be at all sweet so I racked and sulphited them. Also blended in about 15% by volume of this summer's blackberry/blackcurant/strawberry wine to add some je ne sais quoi and make up the space to the bung, and they're now in storage/maturing. No further cellarage activity will be taking place for a bit as I had my R knee "adjusted" on 3 Dec and lifting a 5 gall better bottle is out for a while (along with quite a bit else :-(

So it looks like the shake got it going again, perhaps with some help from the electric blanket - thanks to those who commented and reassured. Lalvin RC202 is off the list for next year!

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Sticky ferment and Lalvin RC212

Sticky ferment and Lalvin RC212

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