This internship project aimed to determine the optimal amount of Lucilite (silica hydrogel) needed to reduce haze in green beer for two brands (NLS and ESB) produced by Nile Breweries in Mbarara, Uganda. Through testing different Lucilite addition rates, the student found that 105g/hl gave the lowest haze for NLS beer and 100g/hl gave the lowest haze for ESB beer. Both of these rates were higher than what was currently being used. The student recommended adopting these new, optimized Lucilite addition rates to improve clarity in the final beer products.

1. Project
Optimum amount of Lucilite required to remove haze from green
beer.
MAKERERE UNIVERSITY
SCHOOOL OF FOOD TECHNOLOGY, NUTRITION AND
BIOSYSTEMS ENGINEERING.
INTERNSHIP PROJECT AT NILE BREWERIES, MBARARA
JULY-AUGUST 2015.
NAME: LUGYA DENIS
REG NO: 13/U/544
STDS’ NO: 213001524

2. Problem statement
NBL Mbarara site’s CI Clarity performance is below 100% because beer hazes are
above CI haze target of < 0.3EBC. The company needed to know the optimal
amount of silica hydrogel (Lucilite) to be added in their 2 main brands (NLS &
ESB) to lower beer haze.

3. Objective of the project.
 Determine amount of Lucilite that can give the lowest haze 90°
reading in green beer.

4. Brief introduction on haze.
Visual appeal is a major factor in the mind of a consumer when
selecting a beer and CLARITY of the beer affects the consumer’s
choice of the product.
Haze is measured at 90° and 25°. Recommended values should be
<0.4 and <0.2 respectively as measured by the haze meter.
Haze in beer is presented as a combination of suspended solids within
the beer from various process stages hence it is better to minimised as
early as possible to avoid:

5. Cont’d
 A lot of filter powder usage during filtration.
 Costly product recall
 Reduced shelf life- haze formation increases as beer is stored before
consumption.
 Weakened brand integrity- consumers may lose trust in your
product.

6. Origin of haze in wort, beer.
The origin of haze in beer will allow a brewer to device means to control the
optimum suspended particles leading to a more consistent and efficient clarification
process.
 Grains- un-malted barley has oxalates that combine with added salts, if not fully
combined with Ca2+ the oxalates remain in suspension hence affecting the clarity.
 Mashing- excessive pressure and over sparging leading to carryover of un-
desirable compounds(lipids, glucans, polyphenols).
 Wort boiling and hop addition- if coagulation temperatures are not efficient,
proteins remain suspended and are not removed at whirpool.
 Fermentation- pH reduction facilitates interaction of polyphenols and proteins
hence haze formation.

7. Composition of haze
Several substances are responsible for haze formation; Proteins,
Polyphenols, CHO(α, β glucans from inadequately modified starch and
residual starch), Inorganic particles from filter aids.
Forms of haze.
Chill haze- soluble at higher temperatures. Formed when polypeptides
and polyphenols are non covalently bonded.
Permanent haze- formed as chill haze but covalent bond soon form and
insoluble complexes are created that will not dissolve when heated.

8. Lucilite and its purpose in brewing.
 It is chemically known as silica hydrogel
 It has the ability to stabilize beer.
 It agglomerates suspended particles (proteins, yeast), thereby
sedimenting them at the bottom by gravity.
 The optimum Lucilite level rate is the one which produces the best
clarity in green beer.

9. Methodology
Apparatus and reagents used:
 500ml sample bottles, spatula
 Beakers, conical flasks, glass rod.
 Haze metre, haze glass
 2.0 litres of green beer(dealt with un-diluted beer sample)
 Lucilite(silica hydrogel)
 Chill box

10. Procedure
 At least 2 litres of green beer were collected from FV5(ESB) and
FV8(NLS) ready to be racked.
 Lucilite samples of 55g/hl, 70g/hl, 85g/hl, 100g/hl, 115g/hl were
prepared in duplicate and mixed in D-water to make a 10% w/v
solution.(for ESB).
 Lucilite samples of 75g/hl, 90g/hl, 105g/hl, 120g/hl, 1135g/hl were
prepared in duplicate and mixed in D-water to a 10% w/v
solution.(for NLS).
 Lucilite slurry was mixed in 420ml 0f beer for ESB and 450 ml for
NLS.

11. Procedure cont’d.
 Controls for ESB and NLS were also prepared.
 Samples were then put in a chill box for a stand time of 30 minutes.
 Beer was filtered using a filter paper and kieselghur.
 Filtrate was then analysed for clarity in a haze glass using a haze
meter.
 Results of beer clarity at 90°(ESB) tabulated.

12. Results

13. Table of Lucilite amounts with respective amount of haze at 90° for
ESB (FV5).
Lucilite amount g/hl
Haze at
90(EBC)
Haze at
90(EBC)
Average haze at
90(EBC)
Control(0) 1.38 1.43 1.405
55 1.14 1.2 1.17
70 1.02 1.01 1.015
85 0.928 0.942 0.935
100 0.820 0.916 0.868
115 0.903 0.959 0.931

14. Results for ESB
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
0 20 40 60 80 100 120 140
A graph of Lucilite amount added against beer
clarity(haze 90) for ESB.
Lucilite amounts in g/hl
Averagehazeat90°(ESB)
Y= −0.0047𝑋 + 1.3893

15. Table of Lucilite amounts with respective haze level at 90ᵒ for NLS
(FV08 LMIB).
Lucilite amounts g/hl
Haze at
90(EBC)
Haze at
90(EBC)
Average haze at
90(EBC)
Control (0) 1.40 1.30 1.35
75 1.01 1.04 1.025
90 0.885 0.857 0.871
105 0.702 0.709 0.7055
120 0.932 0.844 0.888
135 1.03 0.99 1.010

16. A graph of Lucilite amounts (g/hl) against beer clarity (Haze 90) for
NLS.
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
0 20 40 60 80 100 120 140 160
Haze90°(EBC)
Rate of Lucilite addition in g/hl
y= −0.0035 + 1.2777

17. Discussion of results.
NLS and ESB.
 NLS. From my findings, the optimum dosage of Lucilite is 105g/hl
since it gives the lowest haze at 90° in green beer which is lower
than the current standard addition rate at 90.956g/hl.
 ESB. The optimum dosage level of Lucilite which gives the least
haze in green beer is 100g/hl, this is higher than the current standard
addition rate to ESB which is 77.96g/hl.

18. Limitations /sources of errors.
 Lab filtration vs process filtration- no pressure was applied.
 Haze from various sources, could have done a protein test to be
specific of the type of haze.

19. Recommendation.
 I would recommend the use of 105g/hl amount of Lucilite in green
beer(NLS) for improved clarity from my findings
and
 the use of 100g/hl amount of Lucilite in green beer(ESB) for
increased clarity in beer instead of the standard current.

20. Thanks to the supervisors for drafting the project and
all the support given to me.