On 26 Nov, 17:44, pp wrote:
Thanks again,Joe.I think that we are almost there.I will check again
on the sulphite numbers,and also try to see whether I really do get an
ML fermentation.You mentioned a chromatography test-can you buy simple
kits for this?Alternatively,I could taste the wine around Christmas
time-and maybe drink some-and if I like it,add some sulphite then as
you are suggesting.I think that the whites are pretty good early,so
this procedure maybe quite good,provided I do not compromise the wine
by continually unstoppering it to taste!I am sure that if I pick the
white grapes at about 18 Brix,then the quality should be
excellent.With the reds,I believe that I can leave them longer,as I do
not seem to have a problem with oxidation so far.(I mean here longer
in the glass carboy before sulphiting).Incidentally,does it
matter,with regards to oxidation,whether I close the 1 gallon demijohn
with an airlock or with a straight rubber bung or a cork bung.With
these demijohns,being vertical,a cork bung would not be moistened as
in horizontal bottle storage,so probably a rubber bung is
better.However,I have noticed that with my cider making rubber bungs
can go loose at times if there is any excess pressure left-is it wise
to use potassium sorbate if sulphiting early,though I am reluctant to
use even more chemicals,since I am trying to produce a reasonably
organic wine-whatever that really means.Best regards,Michael- Hide quoted text -

- Show quoted text -

Yes, you can buy simple ML kits, at least here in North America, not
sure about Europe. Or, given your background, you could probably
assemble one yourself - the only tricky part is mixing the solvent.
There is also a paper-strip instant test produced by somebody -
Accuvin?

Solid bung will give a better seal, but the wine HAS to be stable and
you should also watch outside temperature fluctuations. It's not much
fun coming back home in summer after an evening soccer game and
finding one's flour covered in 6 gals of blueberry port - the wine was
stable but the carboy cracked because of increased pressure caused by
summer heat.

Pp- Hide quoted text -

- Show quoted text -

Thanks,Joe.I am wary of temperature fluctuations as I keep my wine in
our garage.I try to keep sufficient gap at the top of the 1 gallon
demijohns so that the expanded liquid doesnt force the rubber bung out
in warm summer weather.With my cider making,on several occasions the
rubber bungs have been forced out since the cider was put in when the
cider was not fully fermented out.I am pretty sure that the bungs
would come out of the demijohn rather than crack it,but maybe this is
not always the case.Your 6 gallon carboy which cracked was maybe more
vulnerable and liable to crack at lower pressure than with a smaller
diameter 1 gallon demijohn?I am also aware of downward fluctuations in
temperature,and this is one of the reasons why I was asking you
whether airlocks or bungs are to be preferred-I have noticed on some
occasions that when the temperature drops below zero(outside!)the
airlock goes into a negative pressure state and could pull air in.I
suppose temperature fluctuations for England are probably not as
serious as those where you are in the U.S.Our summers are getting
warmer,but temperatures rarely get above 30C,or below -5C,and then not
for long.

I am reading a book at the moment about a modern French winemaker.It
is the form of a novel but describes his winemaking year in reasonable
detail.He seems to put great emphasis of getting his grapes harvested
and pressed very quickly to avoid oxidation,and retain the fresh
fruity flavours at all stages.He is an organic wine maker,and is
experimenting to see what the minimum of sulphite needs to be added at
the two important stages.That is,initially when the grapes are pressed
and just before the wine is bottled.Unfortunately,he does not give the
quantities!!I hope to follow this kind of practise,and may probably
add 20ppm initially and 30ppm before putting into the demijohns for
longer storage.I may vary this for high or low acid juices(early or
late harvesting),but wish to keep it simple.In your experience,does
20ppm or so initially inhibit the natural fermentation
significantly,and is it enough to do any good at all?

Thanks again for your help,Michael

Hi. It may be a little late this year unless you're conducting
spontaneous/natural malolactic ferfmentation. I'm with Accuvin. We do
make rapid strip tests for L-Lactic Acid (to check that MLF has started)
and for Malic Acid (to verify MLF completion). They are more sensitive
than chromatography, take only 4 minutes, and don't require any other lab
equipment. They might make your MLF monitoring easier.
Regards

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