Hach-Lange DR 5000 brewerie analysis, supplementary software LZV570 - Manual (Page 32)

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Working procedures
Note: Analysis of additional samples: Repeat working procedure from
point 4.
2.7.1.1 Executing the test with the sipper module
Information about the installation, module configurations and
sample introduction of the sipper module can be found in the user
manual of the DR 5000 Spectrophotometer (15.3.3. Installation
Sipper Module, page 133).
2.8 Photometric iodine sample
Photometric iodine sample by new method (MEBAK from 1993).
Principle
High-molecular dextrins and starches are precipitated by adding
ethanol to wort and beer, separated by centrifuging, and dissolved
in a phosphate buffer, to which iodine solution is then added.
Depending on the molecular weight and the degree of branching of
the erythrodextrins and starch, a red to blue colour appears, whose
intensity is measured with the help of a photometer.
Fields of application
Wort, beer (samples whose iodine value is > 0.8 must be diluted.)
Measuring range
0–1 iodine value
Accessories
• Centrifuge
• Centrifuge tubes with ground-glass stoppers (100–110 ml
content)
• Shaker
• Pipettes (0.5 ml, 2 ml, 10 ml, 20 ml, 40 ml)
• Spectrophotometer (578 nm)
• 40 mm rectangular cuvette (OS grade)
• Plastic spatula
Reagents
• Ethanol, 95%
• Iodine solution, 1N (stock solution)