high ph winemaking · • native or “feral” fermentation can be a real thing, it just requires...

High pH Winemaking

Practical TastingTimothy Donahue M.S. Director of Winemaking WWCC

The TeamMarcus Rafanelli, Instructor of Applied WinemakingTim Donahue, Director of WinemakingJoel Perez, Director of ViticultureSabrina Lueck, Instructor of EnologyDanielle Swan-Froese, Program Coordinator

ETS Laboratories St Helena, CA

“This is where a quote can go or a simple

powerful statement or sentence.”—Attribution If Needed

“Everything I am about to tell you is a terrible

idea.”—Tim Donahue

Tempranillo x 2• High pH due do MLF

• Vintage differences

• Do you need MLF?

Syrah x 2• Got Rocks?

• Buffer capacity

• Feral fermentation

• Sulfide evolution

Today’s goals: Taste 4 different wines

Disclaimer

• I am not here to defend a PhD dissertation• These wines were not made in duplicate/triplicate• The trials we are showing today come from student produced wines

that reflect current industry practices • These wines were made in production level volumes and are

representative of the value of internal, practical, applicable research for wineries

• From a scientific perspective, all of this is a bad idea. • Sorry, no refunds

2015 & 2017 Walla Walla ValleyTempranillo

High pH wines from MLF shift

Wines 3 & 4: Tempranillo

Myles Anderson Vineyard (Estate)

Soil Deep wind blown loess on basalt

Trellis VSP

Irrigation Drip

Elevation 426 m ASL

Viticulturist Jeffrey Popick/Joel Perez

Harvest Date October 2, 2015 September 28, 2017

Tempranillo – comparative harvest data

Analysis 2015 2017 Unit

brix 25.1 25 degrees

glucose + fructose 260 265 g/L

pH 3.66 3.61

titratable acidity 5 5.2 g/L

Basic Harvest Data

• On the surface we have very similar basic harvest data.• Do we need more info?

Tempranillo – comparative harvest data

Analysis 2015 2017

L-malic acid 3.04 4.26g/L

tartaric acid 3.8 2g/L

potassium 2130 2420mg/L

yeast assimilable nitrogen 216 117mg/L (as N)

Now for a quick history lesson - 2015

3.043.17

2.972.77

0.86

0

October 2nd October 13th October 16th October 20th October 24th November 9th

Malic AcidMalic Acid

And what do you suppose happened to the pH?

3.663.88 3.98

4.224.44 4.54

October 2nd October 13th October 16th October 20th October 24th November 9th

pH

What do you do about it?

• Pick earlier?

• Tempranillo is tricky in WA. Basic fruit maturity (pH TA Brix) is well ahead of phenolic ripeness.

• Add acid?

• Again, tricky, choice of flavor VS chemistry. Could you add enough acid?

• We tried.

Other options

• Ion exchange?

• Electro-dialysis?

• Do you really have to take a red wine through MLF?

• No

• But

• You must maintain some free SO2 during ageing to inhibit MLF

• You must sterile filter before bottling!

• Monitor microbe populations

• Keep cellar cool

2015• Destemmed to 1.75T SS bin

• QA-23 yeast

• 2X daily punch downs

• Pressed at dryness

• Full MLF

• Aged in 100% new 400L AO

2017• Destemmed to 1.75T SS Bin

• QA-23 yeast

• 2X daily punch downs

• Pressed at dryness

• NO MLF

• Aged in 100% new 400L AO

Production

What’s in your wine? Wine

Scorpion "Yeast and Bacteria Panel" 12/21/2015 8/22/2016 2/13/2017

15 MATO Oenococcus oeni 1700000 156000 144000cells/mL

15 MATOSaccharomyces cerevisiae 81200 22000 11500cells/mL

15 MATO Acetic acid bacteria 2100 21600 22800cells/mL

15 MATO Pediococcus species 1800 1900 1900cells/mL

15 MATOLactobacillus plantarum/casei/mali <10 <10 <10 cells/mL

15 MATO Lactobacillus kunkeei <10 <10 <10 cells/mL

15 MATOZygosaccharomyces

bailii <10 <10 <10 cells/mL

15 MATO

L. brevis/hilgardii/fermentum <10 <10 <10 cells/mL

15 MATOBrettanomyces bruxellensis <10 <10 <10 cells/mL

Wine Data

2015 2017

pH 4.41 3.99

titratable acidity 4.7 6.2volatile acidity(acetic) 0.69 0.17

ethanol at 20C 14.81 14.23

Wine Data

2015 2017

pH 4.41 3.99

free sulfur dioxide 38 35molecular sulfur dioxide <0.10 <0.10

total sulfur dioxide 75 67

L-malic acid 0 2.98

Tempranillo take away

• High pH winemaking is very risky

• If you are going to make wine at these pH levels, SO2 is basically ineffective as an anti-microbial. However; it still has anti-oxidant properties.

• Forget about molecular SO2 (Not that it matters, you have to be insane to do this)

• Are the risks worth the rewards? You decide!

Walla Walla Valley Syrah Buffer capacity, sulfide evolution, stem inclusion

Wines 3 & 4: Syrah

Cockburn Ranch Vineyard Stoney Vine VineyardSoil Deep wind blown loess on basalt Basalt cobbles,

thin windblown loessClone Clone 7 Clone 10Irrigation Dry grown IrrigatedElevation 426 m ASL 228 m ASLViticulturist Cecil Zerba Chris BanekHarvest Date September 12, 2016 October 3, 2016

Harvest data

Cockburn Ranch Vineyard Stoney Vine Vineyard

brix 24.1° 24.7°glucose + fructose 254 g/L 256 g/L

titratable acidity 5.7 g/L 5.8 g/L

pH 3.68 3.87

Harvest Data: Takeaway

• We have VERY similar basic harvest data.

• What else can we look at?

Acids

1.96

1.21

0

1

2

3

4

5

6

7

Cockburn Ranch Stoney Vine

Conc

entr

atio

n (g

/L)

L-malic acid

4

5.8

0

1

2

3

4

5

6

7


Conc

entr

atio

n (g

/L)

tartaric acid

The acid pH disconnect

5.7

6.8

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0


Tart

aric

aci

d eq

uiva

lent

s (g/

L)

total acidity

3.683.87

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5


pH

Potassium & pH

1870

2300

0

500

1000

1500

2000

2500


Conc

entr

atio

n (m

g/L)

potassium

34.1

40.1

0

5

10

15

20

25

30

35

40

45

Cockburn Ranch Stoney VineBu

ffer c

apac

ity (m

M/p

H)

buffer capacity

Acids: Takeaway

• Long extended hang time allowed by the soil/climate increased potassium and subsequently buffer capacity.

• The Stoney Vine is going to have a pretty high pH once it turns into wine.

• Adding acid isn’t going to help here.

Wine Production Comparison

Cockburn Ranch Stoney VineProcessing 40% foot stomp

40% stem inclusion50% foot stomp

70% stem inclusionBlend 91% Syrah, 9% Viognier 100% SyrahYeast Lalvin Rhône 4600® Feral fermentation from PDC

Cap Management Punch down Submerged cap

Maceration Length 10 days on skins/stems 10 days on skins/stems

Nutrition Nutrient additions No nutrient additionsOxygen Additions Macro and meso oxygenation Minimal oxygen additions

Wine Data

Cockburn Ranch Vineyard Stoney Vine Vineyardethanol at 20°C 14.2% 14.41%free sulfur dioxide 31 mg/L 29 mg/LpH 3.86 4.11titratable acidity 5.8 g/L 5.1 g/Lvolatile acidity (acetic) 0.67 g/L 0.47 g/L

Wine Chemistry Takeaway

• Why on earth would you do this?• Well…..

• Stems certainly don’t help lower pH• Lots of potassium in stems

• Good or bad? • Depends on your goals and ability to accept risk.

• So what about that aroma? Deeper?… you betcha!

0.00E+00

1.00E+07

2.00E+07

3.00E+07

4.00E+07

5.00E+07

6.00E+07

7.00E+07

Day 1 Day 2 Day 3 Day 4 Day 5 Day 6 Day 7

Cell

Coun

t (ce

lls/m

L)Saccharomyces cerevisiae strains in uninoculated Carménère

S1 S2 S3 S4 S5 S6 S7 S8 S9

No commercial yeast were harmed during the production of the SVSY

Figure 1. Yeast population profile

Nitrogen's role in fermentation

• Yeast growth (biomass)

• Metabolic functions

• Alcoholic fermentation regulation

• Aroma/flavor compound formation

• (Esters, alcohols, acids, carbonyls, etc)

• Sulfur metabolism regulation

• (Sulfides Mercaptans Thiols)

Nitrogen: Syrah

134

211

0

50

100

150

200

250

300

350

400


Conc

entr

atio

n (m

g/L)

Yeast Assimilable Nitrogen (YAN)

How much nitrogen between the two?

354

211

0

50

100

150

200

250

300

350

400

16 COSY 16 SVSY

Total Yeast Assimilable Nitrogen (Natural + Added)

211 mg/L “au-naturel”

134 mg/L “natural”

220 mg/L “added”

Sulfates, sulfites and sulfides – oh my!

• Sulfides are created through yeast metabolism• S-containing amino acids (sulfate fertilizers)• Nutrient restriction• Elemental sulfur remaining from organic sprays

• Stylistically, some wines aromatic can be built off of various sulfide/reduction compounds.• Burgundian: Pinot Noir – dimethyl sulfide• South African: Pinotage – diethyl sulfide + mercaptins• New Zealand: Sauvignon Blanc – s-cysteine based volatile thiols

Reduced Sulfur Compounds

Compound Aroma

Hydrogen sulfide Rotten eggs, fecal

Ethyl mercaptan Onion, rubber, natural gas

Methyl mercaptan Cooked cabbage, rotten eggs

Dimethyl sulfide (DMS)Truffle, cooked asparagus, cooked corn, cabbage, molasses, quince, canned vegetable

Diethyl sulfide Garlic, onion, strong garlic

Dimethyl disulfide Cooked vegetable, strong onion, cabbage

Diethyl disulfide Strong onion, burnt rubber

(Aroma descriptors from UC Davis)

Sulfide Evolution: How To AVOID

• To DECREASE sulfides

• Use limited amounts of elemental S in vineyard

• Limit use of “sulfate” based fertilizers

• Use foliar urea sprays to increase nitrogen in fruit

• Supplement fermentations with nitrogen during fermentation

• Use oxygen during fermentation

• Rack off of yeast lees

Sulfide Evolution: How To ENHANCE

• Keys to maximizing sulfides• Use organic sulfur in the vineyard• Burn sulfur wicks in barrels (and leave a little behind)• Limit yeast nutrition• Extended yeast lees contact • Large format barrels, large format tank ageing• Minimal (if any) racking• Limit oxygen

Sulfide Evolution: November 9, 2016

1.1

10

0

5

10

15

20

25

30


Conc

entr

atio

n (n

g/L)

dimethyl sulfide

Sulfide Evolution: February 14, 2017

2.2

11

0

5

10

15

20

25

30


Conc

entr

atio

n (n

g/L)

dimethyl sulfide

Sulfide Evolution: April 13, 2017

3.8

18

0

5

10

15

20

25

30


Conc

entr

atio

n (n

g/L)

dimethyl sulfide

Sulfide Evolution: December 1, 2017

3.9

26

0

5

10

15

20

25

30


Conc

entr

atio

n (n

g/L)

dimethyl sulfide

Syrah: Takeaway

• You shouldn’t do this. Really.• Extended hang times increase potassium accumulation & buffer

capacity. • Stems contain significant amounts of potassium, and even when

harvested early, can increase pH and reduce TA.• Earthy, truffle, molasses and even meaty aromatics can be driven

by technique as well as vineyard practices • Native or “Feral” fermentation can be a real thing, it just requires

tinfoil hats and cheap vodka.

At the end of the day…..

• Making wine is great

• Working within the Walla Walla wine community is amazing

• Stewarding people on their life journey is fantastic

• Having the privilege to do both is both awesome and humbling.

Special Thanks

ETS LaboratoriesFor supporting WWCC and for performing all of the analysis.

Dusted ValleyFor the opportunity to work with some awesome Stoney Vine fruit.

Walla Walla Valley Wine CommunityFor being visionary by creating the Institute for EV as well as the incredible support and camaraderie!

high ph winemaking · • native or “feral” fermentation can be a real thing, it just requires...

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