Pp makes a good point. The riper the grapes the more likely it is that
more malic acid has been respired, leaving less substrate for MLF.
Additionally, there are many other compunds influencing pH besides
malic acid. As another data point, I've been using California grapes
harvested at 24 - 27 B for the past 3 years. Typically, I see no more
than a 0.05 - 0.1 point change in pH after completion. For me, MLF has
been much more about microbial stability than style for big reds

RD


William Frazier wrote:
> "pp" > wrote in message
> ups.com...
> I would expect that in (over) ripe grapes there wouldn't be that much malic
> acid left, so a pH
> increase of 0.25 due just to MLF seems too high. Never measured this though
> so have not data to back this up, just a theory.
>
> Pp, the 0.2 to 0.25 pH unit increase is the pH change I've seen following
> malo-lactic fermentation over the years in my grapes.
> Bill Frazier
> Olathe, Kansas USA