jackets - a 42-inch high upper "cooling"
jacket, a 23-inch high lower
"warming" jacket, and a 29 sq. ft.
"warming" floor jacket.
The truncated tank measures 7.5
feet diameter at the top, and 8.5 feet
diameter at the bottom. The advantage
of the truncated tank shape, Hepworth
notes, is that the cap breaks better with
the wider surface area at the tankbottom.
Each tank has a 12-inch diameter
screen tube running the full height of
the tank to a bottom valve, used to collect
juice for pump-over without skins
or seeds, and is also ideal for
There is a Waukesha model-2065,
3hp centrifugal pump for each tank.
This small, gentle pump connects to a
piping system with smaller than typical
dimensions, intended for slower
and more gentle flow of the juice during
pump-over. Piping is a 2-inch
diameter line from the bottom valve
into the pump and a 1.5-inch diameter
return line to the irrigator for pumpover,
operating at 60 gallons per
minute. Other red wine fermentors at
Joseph Phelps have 2-inch lines for
pump-over by a Waukesha-2085, 7.5hp
centrifugal pump with flow rates of up
to 110 gals/minute.
ight new red wine fermentation
tanks, manufactured by Santa
Rosa Stainless Steel (Santa Rosa,
CA) were installed for the 2007
harvest at Joseph Phelps Vineyards (St.
Helena, CA). The new tanks are outfitted
for the gentlest possible handling
of red wine during fermentation.
Delestage is one part of the primary
Ashley Hepworth, associate winemaker
at Joseph Phelps, learned about
delestage during a 10-week working
sabbatical in 2005, observing and participating
in winemaking in Bordeaux.
She was based at Chateau Angelus in
St. Emilion, working with Merlot,
Cabernet Sauvignon, and Cabernet
Franc, and she visited several other
"At Cos d'Estournel, I was
impressed by the use of delestage, and
the results they are achieving," she
says. "In their tank room, they have
much more dramatically 'pitched,'
truncated tanks than I have ever seen."
Delestage involves removing all
juice from the skins in the fermentor to
another tank, then pumping the juice
back over the cap. "The idea is to perform
delestage during active primary
fermentation and to break up the cap,"
Dr. Bruce Zoecklein (Virginia Tech)
reported in his Enology Notes, "Our
delestage research from the 2000 season
suggests that this procedure
reduced the tannin concentration by
35%, reduced the monomeric anthocyanins
by 15%, and increased the
polymeric pigments by 59%,
compared to conventional fermentation
lots. The significant difference in the
large polymeric pigment (LPP) concentration,
coupled with the reduction
of seed tannins, helps to explain the
sensory differences between
delestage-produced and conventional
"Delestage-produced wines are
more fruit-forward and
have a richer yet supple and
integrated tannin structure. Due
to the higher percentage of LPP,
it is assumed that the color stability
of the delestage wines will be
greater as the wines age." (Enology Notes #23, July 2001,
Food Science and Technology at Virginia Tech)
Four straight-side, double-wall
tanks and four truncated tanks (10-ton
capacity with completely insulated
side walls, bottom, and top) were
installed. Each tank has three glycol
One of four new truncated tanks is placed by crane onto the tank pad. Photo by Fred Lyon.