Some standard content:
1 Subject content and scope of application
Industry Standard of the People's Republic of China
Beer malt
QB/T1686-93
This standard specifies the product classification, technical requirements, test methods, inspection rules and marking, packaging, transportation and storage requirements of beer malt.
This standard applies to malt for brewing beer made from double-ribbed and multi-ribbed beer barley through soaking, germination, drying and roasting.
2 Reference standards
Packaging, storage and transportation pictorial symbols
Preparation of standard solutions for titration analysis (volume analysis) of chemical reagents GB603
Preparation of preparations and products used in chemical reagent test methods GB2828
GB5491
GB6682
GB6004
3 Terminology
Batch-by-batch inspection, counting sampling procedures and sampling tables, sampling and sub-sampling methods for grain and oil inspection
Laboratory water specifications
Metal wire woven square mesh for test sieves
3.1 Light malt
Agreement method wort has a chromaticity of 2.5-5.0 EBC units of malt. 3.2 Strong (dark) malt
Agreement method wort has a chromaticity of 9.0 to 130 EBC units of malt. 3.3 Black malt
The color of the wort in the agreed method is malt with a color greater than 130 EBC units. 3.4 Inclusions
refer to all substances other than beer malt and moldy malt, excluding damaged malt. 3.5 Fine powder sample
3.51 refers to the malt sample extracted according to the sampling requirements, mixed evenly, and the hard impurities such as iron filings and stones (excluding other plant seeds and wheat bran, etc.) should be removed, and then the malt sample is crushed by a DLFU disc crusher (Buhler-Miag) with a grinding disc spacing of 0.2mm.
3.5.2 Refers to the malt sampled according to the sampling requirements, which is mixed evenly, and after removing iron filings, stones and other hard impurities (excluding other plant seeds and wheat bran, etc.), it is crushed by other types of crushers and needs to pass through the SSW0.500/0.315mm test sieve. The sieved powder should account for 90%±1% of the total powder. 3.6 Coarse powder sample
3.6.1 refers to the malt sample extracted according to the sampling requirements, mixed evenly, and the hard impurities such as iron filings and stones (excluding other plant seeds and wheat bran, etc.) should be removed, and then the malt sample is crushed by a DLFU disc crusher (Buhler-Miag), with a crushing disc spacing of 1.0mm.
3.6.2 refers to the malt sample extracted according to the sampling requirements, mixed evenly, and the hard impurities such as iron filings and stones (excluding other plant seeds and wheat bran, etc.) should be removed, and then crushed by other types of crushers, which must pass SSW0.500 /0.315mm test sieve, the sieved powder should account for 25%±1% of the total powder of the malt sample. 3.7 Moisture content out of the kiln
The moisture content of malt after roasting at more than 80℃. Commodity moisture
The moisture content of malt when it is traded as a commodity.
4 Product classification
Beer malt is divided into three types according to its color: light color, dark (colored) color and black. 5 Technical requirements
5.1 Sensory requirements
Light malt is light yellow, shiny, has malt aroma, no peculiar smell, and no mold. Dark (colored) and black malt have malt aroma and caramel aroma. Taste, no peculiar smell, no mold. 5.2
Physical and chemical requirements are shown in Table 1.
Inclusions
Water 2)
During saccharification,
≤-light
[2.5~5.0|
Colour EBC
12.5~3.5|
[Dark (pigmented) colour[9.0~130|
Black>
Boiled colour EBC≤light
Extract
Dark (pigmented) colour
(Based on absolute dryness)
Difference between coarse and fine powder%||t t||Viscosity mPa·s
Monoamino nitrogen
mg/100g
Kulbach value
136～49
139~44
%|Dense (color) 25～46
125~49
120~49
25~47—
Saccharification power WK≥
Color 1250
Note: 1) In the column of grade, A in superior product, first-class product and qualified product indicates the limited index, B indicates the general index and C indicates the reference index.
2) Moisture content refers to the moisture content in the furnace; the moisture content of the product shall be implemented according to the contract between the supply and demand parties. 6 Test method
6.1 Test requirements
The water used in this method shall comply with the third-level specifications in GB6882 unless otherwise specified. All reagents used are analytically pure (AR) unless otherwise specified. The "solution" in the test method refers to aqueous solution unless the solvent is specified.
Parallel tests must be performed for the determination of samples. The significant figures in the test method indicate the precision required when aspirating or weighing.
6.2 Sensory organs
Observe the color of the beer malt in a brightly lit place, smell its odor with your nose, and record it. 6.3 Inclusions
6.3.1 Instrument
Physical balance with a sensitivity of 0.02g.
6.3.2 Analysis steps
Weigh 200g of sample, pick out malt mold and other plant seeds, straw, soil, iron filings and impurities, weigh their mass, and calculate their percentage. 6.3.3 Calculation
X1(%)=
Inclusions in malt, %;
Where: X1
The mass of impurities picked out, g.
6.3.4 Allowable difference of results
The difference between parallel tests shall not exceed 0.05%.
6.4 Moisture
6.4.1 Principle
The sample is directly dried at 105107℃, and the percentage of mass lost is the moisture. 6.4.2 Instruments
a. Electric drying oven:
b. Analytical balance with a sensitivity of 0.1mg;
c. Weighing bottle 30mm×50mm;
d. Dryer with color-changing silica gel as desiccant. 6.4.3 Analysis steps
Weigh 5g of fine powder sample (accurate to 0.0002g) into a weighing bottle that has been dried to constant weight. Place the weighing bottle in an electric drying oven at 105-107℃, remove the lid, and bake for 3h, then cover it and move it into a dryer to cool, and weigh it after 30min. Place it in an electric drying oven and bake for 1h, and weigh it until it reaches constant weight. 6.4.4 Calculation
X2(%)=
ml-m
Where: X2——commercial moisture content of malt, %; m—mass of weighing bottle, g;
m1—mass of bottle plus sample before drying, g; m2—mass of bottle plus sample after drying, g. 6.4.5 Permissible difference of results
The difference of parallel tests shall not exceed 0.1%.
6.5 Saccharification time
6.5.1 Principle
Saccharification time is determined by the disappearance of the blue color of iodized starch when a drop of saccharification reacts with iodine solution. 6.5.2 Instruments
a. The mash maker should meet the requirements of the wort preparation process and be equipped with a thermometer and a stirrer: b. The stirrer speed is 80~100r/min;
c. Analytical balance with a sensitivity of 0.1mg;
d. Pharmaceutical balance with a sensitivity of 0.1g;
e. High-precision constant temperature water bath with an accuracy of ±0.1℃; f. White porcelain drop plate;
g. Glass rod.
6.5.3 Reagents
Iodine solution [c(1/212)=0.02mol/L] (2)
Weigh 1.27g iodine and 2.50g potassium iodide, dissolve in water and make up to 500ml, and store in a brown bottle. The solution should be re-prepared every month. Www.bzxZ.net
6.5.4 Analysis steps
6.5.4.1 Preparation of malt juice
Weigh 50.0g of fine powder sample (accurate to 0.1g) into a saccharification cup (500~600ml special metal cup or beaker) of known weight, add 200ml of 46℃ water, and keep it in a 45℃ water bath for 30min under constant stirring. Heat the liquid in a water bath at a rate of 1℃/min, and raise it to 70℃ within 25min. At this time, add 100ml of 70℃ water into the cup, keep the liquid at 70℃ for 1h, and then quickly cool it to room temperature within 10~15min. Rinse the stirrer with water, wipe the outer wall of the saccharification cup dry, and add water so that the content is accurately weighed to 450.0g. Stir the saccharification with a glass rod and filter with medium-speed filter paper. Return the initially collected 100ml filtrate for re-filtration and collect the filtrate in a dry beaker. Note: Each saccharification wort prepared must be measured within 4 hours. 6.5.4.2 Determination of
During the preparation of wort, when the saccharification temperature rises to 70℃ and water is added to the cup, start timing. Take a drop of wort with a glass rod, place it on a white porcelain drop plate, add a drop of iodine solution, and mix well. Observe the color change of the iodine solution. Repeat the test every 5 minutes until the iodine solution is pure yellow, and record this time. 6.5.5 Calculation of
The time required from the start of the water addition timing until the iodine solution does not change color from yellow is the saccharification time. The result is expressed in minutes.
6.6 Chroma
6.6.1 EBC colorimetry (arbitration method)
6.6.1.1 Principle
Inject the wort into the colorimetric blood, use the EBC colorimeter (or SD colorimeter), and compare it with the standard color disk to determine the chroma of the wort, which is the chroma of the malt. 6.6.1.2 Instruments
a. EBC colorimeter (or SD colorimeter);
b. Colorimetric dish 25mm or 40mm.
6.6.1.3 Reagents and Solutions
Hartong Solution
Weigh 0.100g potassium dichromate (K2Cr207) and 3.500g sodium nitroprusside (Na2［Fe(CN)5NO]·2H2O), dissolve in water and make up to 1000ml, store in a brown bottle, place in the dark for 24h before use. This solution is prepared once a month. 6.6.1.4 Analysis Steps
a. Instrument Visual Calibration
Inject Hartong Solution into 40mm colorimetric blood and measure with a colorimeter. The standard reading is 15 EBC units. If there is a deviation, the following formula should be used for correction when measuring the sample. 15×E1
Wherein: X3-
Chroma of malt (wort), EBC unit; Reading when measuring malt, EBC unit: Reading when measuring Hartung solution, EBC unit; Conversion factor, EBC unit.
Take the malt juice prepared in 6.5.4.1, inject it into the colorimetric blood, put it into the colorimeter, compare it with the standard color disk, and read the reading. When measuring dark (colored) and black malt, it should be appropriately diluted and then colorimetric. 6.6.1.5 Calculation
No matter what specification of colorimetric blood is used, the result should be converted into the value of 25mm colorimetric blood. 25×B1
Wherein: X4
Chroma of malt (wort), EBC unit; Reading when measuring malt, EBC unit: Thickness of colorimetric blood used, mm;
Conversion factor, mm.
6.6.1.6 Permissible error of results.
The error of parallel tests shall not exceed 0.25 EBC.
6.6.2 Visual colorimetry with iodine solution
6.6.2.1 Principle
·(4)
In distilled water of the same volume as the malt juice, add iodine standard solution dropwise to make the color of the water the same as that of the malt juice. The number of milliliters of iodine solution consumed is the chromaticity of the malt. 6.6.2.2 Instruments
a. Colorimetric tube 100ml;
b. White porcelain plate;
c. Pipette 0.5ml, graduation value 0.005ml. 6.6.2.3 Reagents and solutions
The iodine standard solution [c(1/212)=0.1mol/L] is prepared and calibrated according to GB601.
6.6.2.4 Analysis steps
Take 100ml of the malt juice prepared in 6.5.4.1 and inject it into a 100ml colorimetric tube, and inject 100ml of water into another colorimetric tube. Place the two colorimetric tubes side by side on a white porcelain plate, and use a 0.5ml pipette to drop 0.1mol/L iodine solution into the colorimetric tube containing water, and shake it continuously until the color of the solution in the tube is the same as that of the sample tube. Record the number of milliliters of iodine standard solution consumed, which is the chromaticity of the sample. When measuring dark (colored) and black malt, it should be appropriately diluted and then colorimetric. The result should be multiplied by the dilution factor. 6.6.2.5 Calculation
Use the following formula to convert the result into EBC units.
Wherein: X5 chromaticity of malt (wort), EBC unit; V——the number of milliliters of 0.1mol/L iodine standard solution consumed for visual colorimetry, ml; 0.06
the approximate conversion factor between iodine solution and EBC unit, ml/EBC unit. 6.6.2.6 Allowable difference of results
The difference between parallel tests of iodine solution titration shall not exceed 0.01ml. 6.7 Boiling chromaticity
6.7.1 Principle
After the wort is boiled in a reflux cooler for 2h, it is filtered with filter paper and compared with the standard color disk through an EBC colorimeter (or SD colorimeter) to determine the chromaticity of the wort, which is the boiling chromaticity of the malt. 6.7.2 Instruments
a. EBC colorimeter (or SD colorimeter);
b. Cuvette 25mm or 40mm;
c. Flat-bottom flask 500ml;
d. Spherical reflux cooler;
e. Constant temperature electric furnace.
6.7.3 Analysis steps
Put 200ml of the wort prepared in 6.5.4.1 into a 500ml flat-bottom flask, put the flat-bottom flask into a glycerin bath, place it on a constant temperature electric furnace, connect a spherical reflux cooler, heat to boiling, keep the temperature at 108±2℃, and reflux for 2h. Remove the flask, cool it to room temperature with tap water, and then filter it with medium-speed filter paper. The visual calibration and measurement of the instrument are the same as those in 6.6.1.4. 6.7.4 Calculation
Same as 6.6.1.5.
6.7.5 Permissible difference of results
The difference of parallel tests shall not exceed 0.25EBC.
6.8 Extract
6.8.1 Principle
Use the agreed saccharification method to prepare the wort, and then measure its specific gravity by the pycnometer method. According to its specific gravity, check Appendix A (Supplementary) to obtain the extract content of the wort, and then calculate the extract content of the malt. 6.8.2 Instruments
a. Analytical balance with a sensitivity of 0.1mg:
b. Temperature-attached pycnometer 25ml or 50ml:
c. High-precision constant temperature water bath with an accuracy of ±0.1℃. 6.8.3 Analysis steps
a. Fill a clean, dry, constant-weight pycnometer with water cooled to 15℃ after boiling, insert a thermometer (there should be no bubbles in the bottle), and immediately immerse it in a 20±0.1℃ high-precision constant-temperature water bath. When the temperature of the contents reaches 20℃, use filter paper to absorb the water overflowing from the branch pipe, cover with a small cap, wipe the bottle wall dry, and weigh immediately. b. Pour out the water, rinse the pycnometer repeatedly with the wort prepared in 6.5.4.1 2 to 3 times, then fill it with wort, and perform the same operation as a. According to calculation formula (6), obtain the specific gravity of the wort at 20℃, and then find the corresponding extract content G of the wort from Appendix A (Supplement). Then use calculation formula (7) to calculate the extract content of malt.
6.8.4 Calculation
Where: D
Specific gravity of wort (at 20℃);
Mass of pycnometer, g;
Mass of pycnometer and water, g;
Mass of pycnometer and wort, g.
G(800+X2)
X6(%)=
Where: X6
(100-G)(100-X2)
Malt extract (on an absolute dry basis), %(m/m);X2——commercial moisture content of the same sample of malt, g;G——extract of the same sample of malt, g;800 is the amount of water added to 100g of malt powder, g. 6.8.5 Allowable difference of results
The difference between parallel tests shall not exceed 0.2%.
6.9 Difference between coarse and fine powder
6.9.1 Principle
Determine the extract content of fine malt powder and coarse malt powder and calculate the difference between the two. 6.9.2 Instrument
Same as 6.8.2.
6.9.3 Analysis steps
6.9.3.1 Preparation of malt juice
Weigh 50.0 g of coarse powder sample (accurate to 0.1 g) and prepare malt juice according to 6.5.4.1. 6.9.3.2 Determination
Determine the extract of coarse powder according to the operation of 6.8.3, and then calculate the extract content X7 of coarse powder according to 6.8.4. 6.9.4 Calculation
X8 = X6-X7.
Where: X8-
Difference between coarse and fine powder of malt, %;
·(8)
X6- Extract of malt fine powder sample (on an absolute dry basis), %; - Extract of malt coarse powder sample (on an absolute dry basis), %. X7-
6.9.5 Permissible difference of results
The difference between parallel tests shall not exceed 0.4%.
6.10 Viscosity
6.10.1 Principle
Use a calibrated viscometer to measure the viscosity of the wort at 20°C. 6.10.2 Instruments
a. Viscometer
Ostwald, HAAKEb, Hoppler viscometer or other viscometer suitable for the viscosity range of wort: b. Super constant temperature water bath with an accuracy of ±0.1°C;
c. Stopwatch.
6.10.3 Analysis steps
Calibrate the viscometer according to the instrument manual, take the wort prepared in 6.5.4.1, and measure it according to the instrument requirements. 6.10.4 Calculation
Calculate its viscosity according to the formula specified in the instrument usage requirements, and convert it into the viscosity when the wort concentration is 8.6% according to the following formula.
Wherein: x9 is the viscosity of the wort when the concentration is 8.6%, mPa·s; E is the viscosity directly read from the viscometer, mPa·s; G is the extract of the same sample wort, g. 6.10.5 Permissible difference of results
The difference between parallel tests shall not exceed 0.05 mPa·s. 6.11a-Amino nitrogen
6.11.1 Principle
Benzotrione reacts with α-amino nitrogen in the wort to obtain reduced benzyltrione, which then reacts with ammonia and unreduced benzyltrione to form a blue-purple complex, the color depth of which is proportional to the α-amino nitrogen content. At a wavelength of 570 mm, the absorbance is measured and the α-amino nitrogen content of the malt is calculated. 6.11.2 Instruments
a. Visible spectrophotometer;
b. High-precision constant temperature water bath with an accuracy of ±0.1℃;c. Test tube 16mm×160mm;
d. Glass ball diameter 20~25mm;
e. Analytical balance with a sensitivity of 0.1mg;
f. Pipette 1, 2, 5ml.
6.11.3 Reagents and solutions
a. Coloring agent
Weigh 10g of disodium hydrogen phosphate (Na2HPO4·12H2O), 6g of potassium dihydrogen phosphate (KH2PO4), 0.5g of triketone and 0.3g of fructose, mix well, dissolve with water and make up to 100ml. Store the solution in a brown bottle and store in a refrigerator. It is valid within one week.
b. Dilution solution
Weigh 2g of potassium iodate (KI03) and dissolve it in 600ml of water, add 400ml of 96% (V/V) ethanol, and store at 5℃. c. Glycine standard stock solution, 1.072g/L Weigh 0.1072g of glycine and dissolve it in water, and make up to 100ml, and store at 0℃. d. Glycine standard working solution
Pick up 1ml of glycine standard stock solution and dilute it to 100ml with water. Prepare it before use. This standard working solution contains 2mg/L of free amino nitrogen.
6.11.4 Analysis steps
6.11.4.1 Preparation of sample solution
Pick up 1ml of the malt extract prepared in 6.5.4.1 and dilute it to 100ml with water. 6.11.4.2 Determination
Take 9 test tubes and number them. Put 2 ml of sample solution in tubes 1, 2 and 3 respectively; put 2 ml of distilled water in tubes 4, 5 and 6 respectively; put 2 ml of glycine standard solution in tubes 7, 8 and 9 respectively. Add 1 ml of coloring agent to each of the 9 test tubes, and put a glass ball on the mouth of each test tube. Put the test tube in a boiling water bath, heat accurately for 16 minutes, and cool in a water bath at 20 ± 0.1℃ for 20 minutes. Then add 5 ml of dilution solution to each tube and shake well. Use the blank liquid tube (tubes 4, 5 and 6) to adjust the instrument zero point and measure the absorbance at a wavelength of 570nm. The measurement should be completed within 30 minutes. 6.11.5 Calculation
A1X2Xn
Wherein: X10
Wherein: X11-
α-amino nitrogen content in wort, mg/L: average absorbance of a sample solution;
-average absorbance of glycine standard solution; α-amino nitrogen content in glycine standard solution, mg/L dilution multiple of sample solution.
X10(800+X2)X10
(100-G)(100-X2)
α-amino nitrogen content in malt, mg/100g anhydrous malt; α-amino nitrogen content in wort, mg/L; X2——commercial moisture content of malt of the same sample, g; 20
Specific gravity of malt wort of the same sample (at 20℃): G—extract of malt wort of the same sample, g. 6.11.6 Permissible difference of results
The difference between parallel tests shall not exceed 7%.
6.12 Coulbach value
6.12.1 Principle
(10)
(11)
The total nitrogen and soluble nitrogen content of malt are measured by Kjeldahl method, and the Coulbach value of malt is calculated based on the percentage ratio of the two.
6.12.2 Instruments
a. Kjeldahl nitrogen analyzer, complete set or self-assembled; b. Analytical balance with a sensitivity of 0.1mg;
c. Burette 50ml.
6.12.3 Reagents and solutions
a. Nitrogen-free water;
b. Concentrated sulfuric acid 98%, nitrogen-free;
c. Sodium hydroxide solution 400g/L
Weigh 400g of sodium hydroxide and dissolve it in 1L of nitrogen-free water. Let it stand and absorb the supernatant into a bottle with a rubber stopper. The specific gravity of this solution is above 1.36;
d. Boric acid solution 20g/L
Weigh 2g of boric acid, dissolve it in water, and make up to 100ml;e. Mixed catalyst
Mix potassium sulfate, titanium dioxide, and copper sulfate (CuS04·5H2O) in a ratio of 10:0.3:0.3 and grind them finely;f. Standard sulfuric acid solution [c(1/2H2SO4)=0.1mol/L] is prepared and calibrated according to GB601;
g. Bromocresol green mixed indicator solution
Mix 1g/L bromocresol green ethanol solution and 1g/L methyl red ethanol solution in a ratio of 10:4. 6.12.4 Analysis steps
6.12.4.1 Determination of total nitrogen
The complete set of instruments shall be used for sample determination according to the instruction manual. The self-assembled instrument shall be operated as follows. a. Sample digestion
Weigh 1.5g of fine powder sample (accurate to 0.0002g), carefully transfer it to a dried Kjeldahl flask, add 10g of mixed catalyst, slowly add 20ml of concentrated sulfuric acid, shake well, heat slowly in a fume hood until the foam stops, and then boil it on high heat. After the solution is clear, continue heating for 20 to 30 minutes. b. Distillation
After the digestion solution cools down, slowly add 250ml of nitrogen-free water, shake well, cool, and add a few small porcelain pieces. Connect the Kjeldahl flask to the distillation apparatus, insert the tip of the distillation tube into a triangular flask containing 25ml of 20g/L boric acid solution and 0.5ml of bromocresol green mixed indicator solution, and the tip of the distillation tube should be below the liquid surface. Add 70ml of 400g/L sodium hydroxide solution to the Kjeldahl flask through an addition funnel, shake gently to mix the contents, and then heat and distill. Stop distillation when the distillate reaches 180ml.
Use 0.1 mol/L sulfuric acid standard solution to titrate the distillate. The end point is when the color disappears from green to gray. Record the number of milliliters of standard solution consumed.
Perform a, b, and c of 6.12.4.1 as a, b, and c for a blank test. d. Calculate
(V2-V1)XcX0.014
X12(%)=
m(1-x2)
Wherein: X12——total nitrogen content in anhydrous malt, %(m/m); -commercial moisture content of the same sample malt, %; X2
the number of milliliters of sulfuric acid standard solution consumed during blank titration, ml; V2-the number of milliliters of sulfuric acid standard solution consumed during sample titration, ml the concentration of sulfuric acid standard solution, mol/L;
mthe mass of sample, g;
the mass of nitrogen in grams equivalent to 1.00ml sulfuric acid standard solution [c(1/2H2S04)=1.000mol/L].
e. The allowable difference of the results
the difference between parallel tests shall not exceed 0.03%.
6.12.4.2 Determination of soluble nitrogen
The complete set of instruments shall be used for sample determination according to the instruction manual. The self-assembled instruments shall be operated as follows. a. Sample digestion
Absorb 25 g of the wort prepared in 6.5.4.1.00ml, carefully transfer to a dried Kjeldahl flask, add 2-3ml of concentrated sulfuric acid, and evaporate carefully until nearly dry. Add 10g of mixed catalyst, slowly add 20ml of concentrated sulfuric acid, shake well, heat in a fume hood over a low heat until the foam stops, and boil it over a high heat. After the solution is clear, continue heating for 20-30min.
After the digestion solution cools, slowly add 250ml of nitrogen-free water, shake well, cool, and add a few small porcelain pieces. Connect the Kjeldahl flask to the distillation device, and insert the tip of the distillation tube into a triangular flask containing 25ml of 20g/L boric acid solution and 0.5ml of bromocresol green mixed indicator solution. The tip of the distillation tube should be below the liquid surface. Add 70ml of 400g/L sodium hydroxide solution to the Kjeldahl flask through an addition funnel, shake gently to mix the contents, and then heat and distill. Stop distillation when the distillate reaches 180ml.
Use 0.1 mol/L sulfuric acid standard solution to titrate the distillate. The end point is when the color disappears from green to gray. Record the number of milliliters of standard solution consumed.
Perform a, b, and c of 6.12.4.2 as a, b, and c for a blank test. d. Calculate
4(V2-V1)XcX0.014XX6
X13(%)=
Where: X13-
Soluble nitrogen in anhydrous malt, %(m/m); extract of malt of the same sample, %;
The number of milliliters of sulfuric acid standard solution consumed during blank titration, ml; The number of milliliters of sulfuric acid standard solution consumed during sample titration, ml; The concentration of sulfuric acid standard solution, mol/L; The extract of malt juice of the same sample, %;
Specific gravity of malt juice of the same sample at 20℃: (13)
The mass of nitrogen in grams equivalent to 1.00ml sulfuric acid standard solution [c(1/2H2S04)=1.000mol/L].
e. The allowable difference of the results
The difference between parallel tests shall not exceed 0.03%.
6.12.5 Calculation of Kulbach value
X14(%)=
-×100
Wherein: X14—
Kulbach value of malt, %;
X12—total nitrogen content of anhydrous malt of the same sample, %(m/m);X13-
6.13 Saccharifying power
soluble nitrogen content of anhydrous malt of the same sample, %(m/m). ·(14)
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