This section takes care of all the raw materials entering the brewery, the materials used in brewing, the packaging materials as well as the fuel/oil used in powering the engines.
The analysis carried out on raw materials (malt, sorghum malt, raw sorghum, maize grist) used in brewing are; moisture content analysis and sieve analysis.
Moisture content analysis:
This measure the amount of water contained in the grains.
Apparatus
Metal curvette, weighing balance, spatula, 130-140 oven.
Procedure:-
1. Grind the sample using the milling machine
2. On the weighing balance and weigh the empty metal curvette
3. Measure 5g of the milled grain into the metal curvettes and add to the initial weight of the metal curvettes.
4. Then place in the 130oC-140oC ovens and allow to stay for 3hrs.
5. After 3 hrs, put in the desiccator for 10 mins and weigh the curvette again. The difference in wt gives the moisture of the grains.
Sieve Analysis:
This measures the fineness or coarseness of the milled grains. When the grist is too fine or too coarse, it will pose a problem during mashing and filtration processes
Apparatus
Retsch Horizontal sieving machine, type 1000 equipped with a set of sieves with diameters ranging from 1.25mm, 1.00mm, 0.56mm, 0.25mm and its bottom, weighing balance, 4 small rubber balls and 4 small rubber cubes.
Procedure
1. Weigh 300g of the sample
2. Place 2 small rubber balls and rubber cubes on each of the finest sieves.
3. Put the sample on the coarsest sieve of the set, fasten the sieves in the machine and set to run for exactly 15 minutes at rotation speed of 300rpm.
4. After 15mins, then start reweighing the quantity of sample in each component of the sieve making sure that you don’t loose any sample
After weighing the different components of the sieve, then add the weight together and see if you can get 300g, which is the original quantity you weighed, then convert the result from each is fine component to percentage, from the result, one can say whether is fine or coarse
Fuel/oil analysis includes;
− flash point
− Water content
− Temperature and specific gravity
Flash point:
Apparatus
Flash point tester, syringe, tissue paper, lighter.
Procedure;-
1. Set the temperature on the flash point tester by press holding the temperature button
2. Introduce 1ml of the sample into the sample cup.
3. Switch the gas supply on and light with a lighter, press start to start ramping.
In every 1◦c rise in temperature it beeps and once it does that, adjusts the shutter until it reaches it’s flashing point. Then read off.
Water content
This measures the percentage of water in the fuel/oil.
Procedure:
1. Add 20mls of reagent A into a beaker
2. Add 1ml of the fuel/oil sample into it
3. Add 1 sachet of calcium hydride into the beaker and shake
4. Transfer the content of the beaker into the black bottom of the machine and press start (shake vigorously for 10 mins and allow to read)
5. Read off the result (the water content should be ≤ 1٪)
Temperature and specific gravity
Procedure:
1. Measure 300mls of the sample into a measuring cylinder
2. Insert the thermometer and read off the temperature
3. Insert the hydrometer and read off the density (density/1000 will give the specific gravity)
Bloom test
This is the analysis carried out on new virgin bottles used in packaging of the beverages. This is to check if there is any phenol ions residue that could be leaching out from the bottle.
Procedure:
1. Measure 100mls of distilled water into the bottle and shake
2. pour into a conical flask and add 3 drops of phenolphthalein and shake
3. If the colour changes to pink, there is presence of phenol ions.
4. Repeat for about 2 times on that same bottle, if there is a colour change, the bottle will be rejected. Otherwise it is accepted.
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