The HCl index is an indicator of the tannin polymerisation state and provides an indication of how these develop over time.
The evolution during the micro-oxygenation of tannins involves an increase in their volume and this index tends to decrease during this phase while it decreases more significantly after fining or during ageing.
The CDR WineLab®method optimises the reference method (Ribéreau-Gayon and Stonestreet) both from the point of view of ease of use and repeatability The standard deviation, in fact, ranges from 4.6 of the reference method to 2.5 of the CDR WineLab® method.
The determination of the HCl index is part of a broad analysis panel developed by the CDR laboratories, implemented on CDR WineLab®, which offers the oenologist a precise and accurate control of both the polyphenolic extraction phase in red wines (maceration), of the subsequent polyphenolic stabilisation phase (and therefore of the colour stabilisation) that occurs with the micro-oxygenation process.
To learn more read ”Controlling Maceration and Micro-oxygenation in the wine-making process“.
The Analyzers CDR WineLab® for determining HCl index in Wine and Must
The system is supplied pre-calibrated and ready for use.
Results are expressed in accordance with the reference method.
It is also possible to standardize the system using samples with a known titration.
The reagents have a shelf-life untill 18 months
The analytical methods are simple: the system does not require an equipped laboratory or skilled staff.
|CDR WINELAB®||CDR WINELAB® JUNIOR|
|Analyses||Wine and Must:
Alcohol by Volume
Acetic acid (volatile acidity)
Free sulfur dioxide
Total sulfur dioxide
Yeast Assimilable Nitrogen (YAN)
Total Polyphenols Index
Colour (tonality and intensity)
Total Polyphenols (Folin Ciocalteu)
Anthocyanins on grapes
|Configuration with tailored panel of analyses|
|Simultaneous Sample Analyses||16||3|
|Multiple Analyses on a Sample||–|
Test type: End Point.
Time testing: 6 minutes.
the analysis involves a sample incubation time of 7 hours.
Are possible test sessions with several samples, up to a maximum of 16.
The correlation curve of the determination of the HCl index in wine with CDR WineLab®, carried out with respect to the Ribéreau-Gayon and Stonestreet reference method.
This index is based on the instability of procyanidins, catechin oligomers, in a highly acidic environment. In conditions of high acidity these molecules tend to polymerise, forming brown polymers. The most condensed molecules precipitate rapidly while the least condensed tannins remain in solution.
Reagent test Kits
The reagents are packaged in foil pouches containing 10 tubes useful to perform 10 analyses.
This is the minimum package that allows the use of CDR systems even to those who need to make a few analyses, thus not wasting reagents.
There are also boxes of 100 tests, however, packaged in 10 bags of 10 tubes containing the reagent.
Code. *301035: 10 tests
Code. *301030 : 100 tests (10 packages of 10 tests)
The reagents have a shelf-life of 8 months.
Wine: Use the wine as it is after centrifugation.
Must: Use the must as it is after centrifugation and degassing.
|HCl Index||5 – 50||0||2.5|