Cross Industry Oxygen Management Forum
Oxygen is not always
bad in winemaking
Martin Day
2018 WEA South Australian Conference Program
26th July 2018
Oxygen Balance – perceived effect of closure OTR
Fault rates in International Wines
All
5%
4%
3%
2%
1%
0%
0.8%
0.9%
100,000 entries over 10 years
Evolution of methanethiol during bottle ageing
Mean increase in MeSH
mL O2 / mth0.30
0.24
0.18
0.12
0.06
0.00ST SX TC Gl Syn Cork
Spread of different OTR closures
Evolution of methanethiol during bottle ageing
Cross-linked polymers
Copper & iron scavenging
White wine
CLP1 = N-vinyl imidazole
CLP2 = Iminodiacetic acid (Na+)
Co
pp
er
(mg
/L)
Co
pp
er
(mg
/L)
Red wineIr
on
(m
g/L
)
Iro
n (
mg
/L)
Free SO2 depletion
White wine Red wine
FS
O2
mg
/L
FS
O2
mg
/L
Metal concentrations after red ferment aeration
8 x 10 L/min for 60 mins / 540 kg Shiraz; 2 months after bottling
Fe Cu (x10) Zn (x10)
Mean of 3 fermenters; error bars ±SE
40% O2 21% O2 No gas N2
aa
aa
ab
b
b
bbb b
0
1
2
3
Met
al (
mg/
L)
Barossa CHA, 2015
Timing or dose-related efficiency effects of
oxygen use in whites during ferment
3 6 9 1 2 1 5
0
5 0
1 0 0
1 5 0
2 0 0
t im e (d a y s p o s t in o c )
Su
ga
r c
on
ce
ntr
ati
on
[G
+F
] (g
/L)
E a rly -S h o rt
E a rly -L o n g
L a te -L o n g
C o n tro l
E a r ly L a te
* in d ic a te s s ig n if ic a n t d iffe re n c e c o m p a re d to 'N o tre a tm e n t'
u s in g D u n n e tt t (P = 0 .0 5 ) p o s t-h o c te s t
E S E L L L N T
0 .5
1 .0
1 .5
2 .0
To
tal
Ph
en
oli
cs
(a
u)
*
A B
B
A B
A
E S E L L L N T
0 .0 4
0 .0 5
0 .0 6
0 .0 7
0 .0 8
0 .0 9
A4
20
(a
u)
*
B B B
A
Further red wine trials V16
Treatments:
▪ ‘Daily’ x4
▪ When TSS dropped by 20% (‘Early’)
▪ When TSS dropped by 80% (‘Late’)
▪ No sub-cap air addition (‘No Trtmt’)
▪ Post-press on ‘No Trtmt’
11
O2
DO out
DO in
O2
DO out
DO in
Stage 1: Cap irrigation (3 mins) Stage 2: sub-cap recirculation to set DO
0 5 0 1 0 0 1 5 0 2 0 0
1
3
5
7
tim e
DO
(m
g/L
)
D a ily
E a r ly
L a te
N o T r tm t
‘Vortex sparger’
Descriptive Sensory Analysis
Daily
Early
Late
Post Press
Opacity
Overall Fruit ARed Fruit A
Confection AFloral A
Vegetal AVanilla A
Earthy A
Wood A
Red Fruit F
Black Olive F
Viscosity
Acid
Hotness
Astringency
Fruit AT
PC1 (67.2 %)
PC2 (17.9 %)
No trtmt
Chemical differences --
decrease with ‘Daily’:
• Total phenolics
• Mean degree of polymerisation
• Total free anthocyanins
• Wine colour density
decrease with ‘Early’ & ‘Daily’
• Hydrogen sulphide
disappearance with ‘Daily’
• Methyl thioacetate
Measuring dO2 using LDO
SCADA/
Process-integrated
Hand-held meters:
tank drop-in
www.presens.de/fileadmin/user_upload/basics/web_O2_Measurement_Principle.jpg
Measuring dO2 using LDO
https://resource.hach.com/animations/LDO/LDO.swf
Acknowledgements
This work is supported by Australia’s grapegrowers and winemakers
through their investment body Wine Australia, with matching funds
from the Australian Government. The AWRI is a member of the Wine
Innovation Cluster in Adelaide.
Team AWRI: Alice Barker, Marlize Bekker, Keren Bindon, Stella Kassara, Paul Smith
Neil Scrimgeour & AWRI Commercial Services Project Team
