|Range||0.0 to 15.0 mg/L|
|Accuracy @25°C||±0.2 mg/L ±5% of reading|
|Light Source||tungsten lamp|
|Light Detector||silicon photocell with narrow band interference filter @ 560 nm|
|Method||the reaction between iron and the reagents causes a purple tint in the sample|
|Environment||0 to 50°C; RH max 95% non-condensing|
|Power Supply||1.5V AA batteries (4) / 12 VDC adapter|
|Auto-off||after 15 minutes of non-use|
|Dimensions||225 x 85 x 80 mm (8.7 x 3.3 x 3.1”)|
|Weight||500 g (17.6 oz.)|
Iron Concentration and Casse
HANNA HI 83741 measures the iron concentrations of both white and red wines. HI 83741 makes it possible to quickly and easily determine the state of your wine, and to act on it in case it may be necessary.
Significance of Use
Trace iron concentrations in wine are beneficial for enzyme activity, as a stabilizer, and as a functional component for proteins.
At higher concentrations it alters the redox potential, in favoring oxidation, affecting sensory characteristics and participating in the formation of complexes with tannin and phosphates resulting in instabilities (casse). The most common iron case is “white casse” (iron phosphate), it is initially seen as milky white cloud and later as a precipitate. The “blue casse” (ferric tannate) that occurs less often can be observed in white wines, for example, after tannic acid additions.
Most of the iron present in wine is present in the ferrous Fe (II) state. The ratio of the Fe (II)/Fe (III) depends on the oxidation state of wine. If Fe (III) is formed, it can bind with phosphates that are normally present in wine.
Since iron strongly binds with several organic acids, some wine makers add citric acid to the wine to complex free iron if the concentration exceeds 5 mg/L. If no contamination, occurs the normal concentrations must be in range from 1 to 5 ppm. The most important source of iron in wine is contact with iron containing alloys during processing. During fermentation a part of the iron is absorbed by yeast and thus removed from the wine during filtration.
Iron Concentration & Casse
Wine containing less than 8 mg/L of iron: there is no risk of casse.
Wine containing more than 8 mg/L of iron: it is necessary to check the stability since there may be the possibility for casse to occur.
Wine containing 8 to 15 mg/L of iron: wine is subject to casse and needs treatment with SO2, citric acid or ascorbic acid.
Wine containing over 15 mg/L of iron: wine is highly subject to casse and needs treatment with potassium ferricyanide.
HANNA’s HI 83741 is an invaluable instrument for monitoring this crucial parameter in the process of wine making. With a few simple steps wine makers can quickly and accurately measure iron content in wine directly in mg/L.
HI 83741-01 (115V) and HI 83741-02 (230V) is supplied with sample cuvettes and caps (2), reagents for 5 tests (HI 83741A-O, HI 83741B-O, HI 83742-O), scissors, 1000 µL automatic pipette with instruction sheet, plastic tips for 1000 µL automatic pipette (2), 1 mL plastic pipette, cuvette cleaning cloth, 12 VDC adapter, batteries, instructions, instrument quality certificate and rugged carrying case.