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