This method describes how to correctly collect a sample of water.
Water intended for use as an ingredient in the production of beer (brewing liquor) or other foods
Collecting samples correctly is a prerequisite for obtaining flawless analytical results. The sample collection method must be adapted to align with the purpose of the analysis method. As a rule, separate samples are taken for chemical and microbiological analyses, since different equipment and containers are required for the collection and treatment of samples.
In principle, sample collection methods are distinguished as follows:
Random samples collected for analysis identify possible contamination or can be collected for purposes of orientation prior to more extensive sampling.
Both intermittent (discontinuous) sample collection (according to certain time intervals, volumes or flow rates) and continuous sampling, which allows for constant monitoring of flowing water for compliance with quality standards, are possible. Samples taken continuously can be mixed to create composite samples and provide mean data.
A series of samples (taken at different depths or over a given area to perform profile tests) are collected for analysis in the process of testing standing water.
Determination of the original gravity, alcohol and extract content using an oscillating U-tube density measuring device and an alcohol sensor in beer or beer-based beverages
Aside from the density, the alcohol concentration is also directly measured with an alcohol sensor. This is carried out using catalytic combustion. In a measured stream of air, alcohol vapor rises countercurrent to the beer flowing downwards. The alcohol vapor is oxidized at the sensor and the resultant heat is measured by means of a resistive circuit. This correlates with the concentration of alcohol in the beer. According to Tabarié’s equation, the relationship between the specific gravity of beer, its alcohol content and real extract content can be calculated as follows:
\(\rho_{\text{beer}} = \rho_{\text{alcohol}} \space + \space \rho_{E_R} \space – \space \rho_{\text{water}}\)
\(\text{SG}_{\text{A20/20 beer}} = \text{SG}_{\text{A20/20 alcohol}} \space + \space \text{SG}_{\text{A20/20}}E_R \space – \space \text{SG}_{\text{A20/20 water}}\)
\(\text{SG}_{\text{A20/20 alcohol}} = 1.000\)
This method describes the conditions under which sensory analysis should be carried out.
beer, beer-based beverages, non-alcoholic beverages, mineral water
One of the basic prerequisites for properly conducting sensory analysis is choosing an appropriate number of samples and presenting them to tasters in the relevant sequence.
The method describes the appropriate procedure for sample collection of adjuncts, barley and malt.
Material, which is intended for processing in a food production facility, must be sampled prior to or at the time of delivery.
Determination of the correct Velcorin® dosage
flavored beverages, liquid tea concentrate, fruit wine, non-alcoholic wine
DMDC (Velcorin®) is used for the cold sterilization of non-alcoholic beverages. It essentially kills yeasts, bacteria and molds, with little effect on mold spores or yeast ascospores. Certain species of Lactobacillus possess an elevated resistance to Velcorin®.
There should be fewer than 500 microbes/cm3 at the time the dosage is added.
According to the EU guideline EG 1129/2011 [1], up to 250 mg/l DMDC may be added to flavored non-alcoholic beverages, non-alcoholic wine and liquid tea concentrates.
Dimethyl dicarbonate (Velcorin®) quickly dissociates in aqueous solutions almost completely to carbon dioxide and methanol. In addition, small amounts of ethyl methyl carbonate are formed through the reaction of DMDC with ethanol, which can be detected through GC-MS analysis techniques [2]. The amount of DMDC added to a beverage can be determined by measuring the content of EMC and ethanol. The Velcorin® dosage can be checked by measuring the amount of methanol quantitatively using GC analysis; however, the initial amount of methanol present in the product prior to adding Velcorin® must be determined.
H2O + C4H6O5 (DMDC) → 2CH3OH + CO2
250 mg Velcorin → 119.5 mg methanol + 164.1 mg carbon dioxide
C2H5OH + C4H6O5 (DMDC) → C4H8O3 + CH3OH+ CO2
Determination of sorbitol by ion chromatography and pulsed amperometric detection
This method is suitable for fruit juices and other non-alcoholic beverages.
The sugar alcohols are separated using a strongly alkaline eluent and ion exchange column and detected and quantified electrochemically using a pulsed amperometric detector (PAD).
By applying a potential, the ions are oxidized at a gold electrode and induce a measurable charge. To prevent the electrode from being occupied in a very short time, the potential is then reversed to reduce and release the ions from the electrode.