Measuring Baume

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DEPARTMENT OF PRIMARY INDUSTRIES

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Measuring Baume

Kerry DeGaris

Technical Officer

Hardy Wine Company


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Introduction

History to measuring baume in grapes

Why measure sugar levels?

How sugars develop in vines

Sampling

Measuring sugar in field


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Baum or Brix

Baum (named afterAntoine Baum),measure of sugar

content Indicates potential

alcohol that may beachieved

Historically used inAustralia


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Baum or Brix Brix named after Adolf

Brix, measure of theconcentration of sugar insolution

Expressed as the %byweight of sugar in solutionat a specified temperature

Scientists and some

wineries prefer this term 1.8 Brix = 1 Baume


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Why measure Baum / Brix?

Brix is a measure of sugar and thus givesan indication of potential alcohol levels

Higher Brix levels generally indicate higher

potential alcohol levels Currently Brix is the best readily availableindicator to determine when grapes are

optimal for winemaking.


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Why measure Baum / Brix?

Date of harvest can be predicted

Regular measurements of sugar level duringthe ripening period can determine time of

harvest Most wineries have a minimum Brix level tobe reached before they accept grapes for

processing


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Red Grapes Minimum Baume

12.5Tyrian

13.5Cab Sav13.5Merlot

13Mataro

13Petite Verdot

13Ruby Cab

14Red Fronty

10Pinot Noir

Min BaumeVariety


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Berry Ripening in the Riverina

Sampling Date

V V+2 V+4 V+6 V+8 V+10

DegreesBrix

5

10

15

20

25

200020012002


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Sampling

Need to ensure they are representative

Sample size depends on variability of vineyard

And also the variability within the vine

Samples need to be taken at the same time eachday

Examples of methods:

5 bunches out of a transect from 4 vines

40 bunches from each of 40 vines


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Processing sample

Grapes can be cooled stored

Crush with out breakingseeds

Clarify juice Process sample immediately

Juice should not be storedand then measured


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Measuring Sample -Hydrometer

Hydrometers measures the specific gravityof a solution

This relates to the total soluble solids or

sugar content Sugars represent 90-94% of all total soluble

solids

Also useful to follow the progress offermentation


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Hydrometer - procedure Fill cylinder to about

10cms from top

Rinse hydrometer witha little juice before

putting in juice Place in cylinder gently

and push to bottom

Move up and down tomix juice

Spin hydrometer toremove air bubbles


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Hydrometer - procedure

When settled, read theindicated reading at thebottom of the meniscus

Insert a thermometer into

the juice and readtemperature

Apply temperaturecorrection

Baume hydrometers forevery C above or below 20add or subtract 0.05Baume, respectively


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Temperature Correction Example

Example 1

Sample with a Baume reading of 13.5 and atemperature of 22C.

True reading of 13.6 Baume (13.5 +0.10)

Example 2

Sample with a Baume reading of 12.2 and atemperature of 17C.

True reading of 12.02Baume (12.2-0.18)


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Hydrometer Source of Errors

Incorrect reading of hydrometer

Reading should be taken at the bottom of the meniscus

Faulty hydrometer

Should be checked against a known sugar solution

Failure to measure juice temperature

No application of temperature correction factor

Hydrometer not floating freely

Due to suspended solids, hydrometer must be floating freely

Unclean hydrometer

Must be free from grease, dirt and detergent residue


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Measuring sample - Refractometer

Refractometers are instruments designed tomeasure the refractive index of a solution

This means to what extent a beam of light is bent

when it passes through a solution The degree to how far the light is bent depends on

the levels of total soluble solids

Refractometers are calibrated to give theconcentration of total soluble solids in Brix.


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Measuring Procedure Hand heldrefractometer

Open prism box Place a drop of juice on the glasssurface (make sure it is covered)

Close prism box

Hold towards light source

Read graduated scale, where lineintersects two regions (dark &light)

Most refractometers these days

automatically temperaturecorrect.


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Measuring procedure Bench toprefractometer

Instructions varydepend on the machinebought

Same principles applyto a bench top as for ahand held

Usually automaticallytemperature correct


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Refractometer-Source of Error

Unclean prism

Clean with ethanol (70%)

Use distilled water to zero instrument


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Summary

Sugar measurement is a tool used toindicate the ripeness of grapes

The use of Brix or Baume is a personal

preference It also relates to alcohol in wine

A few simple techniques allow this

parameter to be easily read in the field.

Measuring Baume

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