most winemaking recipes i have read say to wait 12hours after adding a
campden tablet before adding pectic enzyme.why is this? does the SO2
affect / inhibit pectic enzyme?

no.

you just want to add the pectic enzyme before fermentation starts since
it does not last long afterwards.

Droopy wrote:
> no.
>
> you just want to add the pectic enzyme before fermentation starts since
> it does not last long afterwards.

What happens to it? - haven't heard this reason before...

Thx,

Pp

pp wrote:
> Droopy wrote:
> > no.
> >
> > you just want to add the pectic enzyme before fermentation starts since
> > it does not last long afterwards.
>
> What happens to it? - haven't heard this reason before...
>
> Thx,
>
> Pp

Alcohol inhibits its activity and yeast secrete enzymes that break it
down.

raindog wrote:
> most winemaking recipes i have read say to wait 12hours after adding a
> campden tablet before adding pectic enzyme.why is this? does the SO2
> affect / inhibit pectic enzyme?

Jack Keller says, buried somewhere on his website, that the SO2 gas
released inhibits pectic enzyme. And like Droopy says, yeast use must
proteins to grow, and the pectic enzyme you added works just fine as
yeast food.

I figure all this is at least plausible, so I do wait -- crush,
sulfite, wait 12 hrs, pectic, wait 12 hrs, pitch yeast. If you're
bored, use the time to make up a starter culture.

Maybe all this waiting was historically done so the must macerates, so
some time passes between crush and fermentation. So other enzymes in
the fruit can mature flavors, extract colors, or whatever. C.J.J.
Berry seems to suggest that the SO2 exposure causes natural glycerol to
form -- but he's usually short on the science.

Don't be afraid that the juice is going to become a musty, moldy,
vinegary, spoiled mess in 1 day out.

Our modern sterile culture has ruined us -- "You left the OJ out of the
fridge after breakfast!" "Oh noes! Dump it down the drain before one
of the kids drinks it!" Its a good thing we have modern technology to
save us from tepid fruit -- or else everyone would have to make wine to
get their vitamin C. And then our hobby would be a common household
chore like dishwashing.

wrote:
>
> Jack Keller says, buried somewhere on his website, that the SO2 gas
> released inhibits pectic enzyme. And like Droopy says, yeast use must
> proteins to grow, and the pectic enzyme you added works just fine as
> yeast food.
>

This question pops up on a somewhat regular basis - if you do a search
on the archive, there is a post from a guy from Scott Labs who said
that's true only at free SO2 levels of 200ppm and more, so there is no
issue in sulfiting and adding pectic enzyme around the same time.

Pp