Wine yeast for reducing malic acid levels
CiderHead
have discovered a wine yeast "Gervin Red-on-white label, Strain GV11"
which, the notes say, "will metabolise up to 30% of the malic acid".
Since a lot of the apples I use are high in acidity and I tend to have
to reduce it using rather expensive potassium hydroxide, I am
wondering if, in future, I could use this yeast in my fermentation,
perhaps along with natural or other commercial yeasts. Does anyone
have any experience with this yeast or have any comments about this
idea?
I know that one possible solution to high acidity is malo-lactic
fermentation and this has been discussed before on this forum.
However, the reason I haven't gone down this route is that, from what
little I know about it, it seems to require relatively warm
temperatures (ca. 17C - warm compared to average winter temperatures)
and I would like to sort out the acidity earlier rather than later.
Cheers,
Martin
Andrew Lea
> In the home brewing shop in which I've recently started working, I
> have discovered a wine yeast "Gervin Red-on-white label, Strain GV11"
> which, the notes say, "will metabolise up to 30% of the malic acid".
> Since a lot of the apples I use are high in acidity and I tend to have
> to reduce it using rather expensive potassium hydroxide, I am
> wondering if, in future, I could use this yeast in my fermentation,
> perhaps along with natural or other commercial yeasts. Does anyone
> have any experience with this yeast or have any comments about this
> idea?
>
This came up here last August. Search the archives for a thread called
"Yeast 71B". (Note that the Gervin yeasts are normal commercial strains
which have been re-packaged and re-labelled).
Andrew
--
Wittenham Hill Cider Page
http://www.cider.org.uk
Claude Jolicoeur
> In the home brewing shop in which I've recently started working, I
> have discovered a wine yeast "Gervin Red-on-white label, Strain GV11"
> which, the notes say, "will metabolise up to 30% of the malic acid".
> Since a lot of the apples I use are high in acidity and I tend to have
> to reduce it using rather expensive potassium hydroxide, I am
> wondering if, in future, I could use this yeast in my fermentation,
Wyeast 4783 on the same batch of juice. And in effect, the 71B did
reduce the acidity by about 20% when compared with the 2 others. It
also left a tiny bit of residual sweetness. I have recently started to
drink those ciders and the one made with the 71B is my favorite. The 2
others are quite equal although there is a slight difference in aroma.
I prefer the one made with EC-1118, but my wife prefers the one made
with Wyeast 4783! So we will put them at equality.
I didn't use the 71B in 2010 because the summer has been so great, and
there was much less acidity in the juice, like 30-40% less than for an
usual year. So I thought there was no point in using it under those
conditions. But I do intend to use it more on years where the acidity
levels will be more normal.
Claude
CiderHead
On Mar 11, 3:10 pm, Claude Jolicoeur <cj...@gmc.ulaval.ca> wrote:
> I did side-by-side tests in 2009 with the Lalvain 71B, EC-1118, ...<
Hi Claude,
I found your post in the archives and it was certainly interesting.
It's too late for doing any tests using fresh-pressed apple juice but
I think I'll try and do a test on one of the cider "kits" that we sell
in the home brewing shop I now work in (most customers think they're
horrible!). For one thing, I know the juice is pasteurised so there
will be no contamination from wild organisms. I think I'll use one and
put in some extra malic acid and measure the before and after grams/
litre levels using this 71B yeast.
As an aside, to everyone, I notice I said in my original post that
I've use potassium hydroxide to reduce the acidity levels - err, make
that potassium carbonate. I'm surprised nobody tore me to bits on that
one!.
Cheers,
Martin
Andrew Lea
>
> As an aside, to everyone, I notice I said in my original post that
> I've use potassium hydroxide to reduce the acidity levels - err, make
> that potassium carbonate. I'm surprised nobody tore me to bits on that
> one!.
Well we try not to tear people to bits here ;-) Not the Cider Workshop
style!! But there is no reason you couldn't have used potassium
hydroxide (if you had any. Most people don't because it is very strong
and very caustic and not really suitable for handling outside of a
chemistry lab).
BTW Gervin Yeast D GV11 is the same as Lallemand 71B see eg
http://www.stonehelm.co.uk/Yeasts.html As a bit of background, it's
quite a few years now since Gervin was set up as a hobby business by
Gerry Fowles, a Professor of Inorganic Chemnistry at Reading University
(though long retired now). Repacking and selling top quality dried
yeasts in small quantities for home winemakers was one of his strengths
since there was quite a lot of .. err, unbranded untraceable rubbish, on
the market at that time (late 70's). He also published a couple of
excellent and scientifically sound books for home fruit winemakers and
did a certain amount of consultancy for the new English winemakers using
home-grown grapes as that business was taking off. This was in the
Reading University Bulletin in June 2007:
"Professor Gerry Fowles who retired
in 1991 after 26 years as Professor of
Chemistry, has maintained his special
interest in oenology (the science and
study of wine making) on both the
amateur and professional levels.
He is an honorary life member of the
United Kingdom Vineyards Association
and serves on the editorial board of
the Journal of Wine Research, which is
published by the Institute of Masters of
Wine. He has just received notification
that the American Society for Enology
and Viticulture has awarded him
an Honorary Emeritus Membership
in �Grateful Appreciation and
Acknowledgment of Many Contributions
to the Fields of Viticulture and Enology�."
John Schroeder
I did a similar side by side test with 71B, DV10, and EC1118 with a
similar result in terms of reducing acidity. I also preferreed them
in that order. Two quick questions for you:
1) the secondary lees for the 71b took twice as long to settle and
clarify, and even then were not compact at all. The slightest
movement kicked up vast clouds of sediment. Did you find this as well
and is it typical of 71b?
The ec1118 was extremely compact and cleared the fastest, while dv10
similar to ec1118 but slightly more secondary lees and took a bit
longer to clear. Overall i found 71b to be a bit difficult to manage.
2) would you mind sharing what you would consider high acidity versus
optimal in g/l of malic acid?
Thanks!
Regards,
John
Claude Jolicoeur
>1) the secondary lees for the 71b took twice as long to settle and
>clarify, and even then were not compact at all. The slightest
>movement kicked up vast clouds of sediment. Did you find this as well
>and is it typical of 71b?
I must say this test is the only time I used 71B. As I have mentioned,
since acidity was low in 2010 I didn't use it as I wanted to preserve the
acidity that was there.
As of lees, the 71B did behave in a special way... The 3 batches started
quite rapidly (this was a first season cider, which was started end of
September - these always ferment more quickly) and by first racking, after
2 weeks, SG was down to 1.022 (Wyeast) and 1.027 (the 2 Lalvain ones) from
an initial gravity of 1.053. However, about a week after this first
racking, the 71B batch proceeded to do a natural keeve. You can see it on
the attached picture, certral carboy. I have no explanation for that, but
by Oct 20, the cider was perfectly cleared with the chapeau brun floating.
I let it do its fermentation like that; the picture was taken on Feb.28. I
bottled it a little while later at a SG of 1.009 without adding any extra
sugar or yeast. After a year in bottle, SG has dropped to 1.002 and it is a
very nice mousseux cider with a hint of residual sweetness. All that to say
that no, I didn't have any sedimentation problems...
>2) would you mind sharing what you would consider high acidity versus
>optimal in g/l of malic acid?
On normal years, my normal apples will give a juice around 9 g/l of malic,
which is a bit too high once the cider has fermented to dryness. I now have
some production from low acid varieties that I use for blending. I normally
aim for 6.5 to 7.5 g/l malic for my blends, and this reduces somewhat with
MLF (I don't do anything for this - it just occurs). Usually, by drink
time, acidity is down to about 4 to 5 g/l. In 2010, my juices were at about
6 g/l malic, and this is why I didn't use the 71B.
Claude
P.S.see also this thread:
http://groups.google.com/group/cider-workshop/browse_frm/thread/24235f1d07e4
3250/6b6ed540c25f4124
