This document contains the results of various chemical analyses and experiments on winemaking processes. It discusses methods to determine precision and reproducibility in a new analytical method. It also examines monitoring grape ripening, sampling techniques, and factors that influence fermentation rates in different wine tanks. Recommendations are provided to improve accuracy in the winemaking process and to enhance marketing at MW Wines.

1. Ana Cristina Romão
Name: Ana Cristina Romão
1. Result: 119.8396 g/L
2. Result: 9.24708 min ≈9.25 min
3. To determine the procedure’s Precision in void to applied a new method, I need
to test repeatibilty and reproducibility of the method. The condicions of
repeatibilty are: using the same process, with identical analytical material and
same conditions (same analysts, same equipment, same lab, in short time). It’s
necessary to define limit of repeatibilty (r), is the value below which can be
expected that falls the absolute difference between two analysis results obtained
in terms of repeatability for a given probability, in the absence of any indication of
the probability is 0.05.
For reproducibility of the new method, I need conditions in which the results are
achieved on analyzing the same material, but under different conditions (different
analysts, different apparatus, in different laboratories and / or at different times).
It’s necessary to define limit of reproducibility (R), It is the value below which can
be expected is equal to the difference between two analysis results obtained in
reproducibility conditions for a given probability, in the absence of any indication
of the probability is 0.05.
4. Result: 1,455 g
5. Result: pH=7.17
23
6. Results: n=0.0375 mol; n= 0.0025 mol; n=0.0025 mol; N=1.5X10 (number of
H+ ions)
7. There are 3 produts that causes “lagrima” or “legs” in wine: glycerol (secondary
produt result fermentation of yeast or lactic bacteria), alcohol (wines with high
alcohol content are more bond) and sugar (sweet wines like Madeira due its
“legs”). If wine was served during dinner, isn’t for sure a sweet wine and if my
college is wrong with glycerol is cause for that characteristic, the only reason is
alcohol.
8. The ° Brix is the amount of sucrose in grams per 100 grams of must. When this
value due above 0º means that exist an error of measure using a hydrometer
because at the end of fermentation residual sugar normally is around 2 g/L or
less. In this phase of fermentation there are other solids in suspension that
induce that Brix values above 0º, when we use hydrometer. In this situation we
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2. Ana Cristina Romão
have to use other methods more precise to obtain residual sugar and alcohol
content.
Problem A
1. The concepts of maturation not depend only of the degree or state of grape
chemical compounds accumulation and berry volume but also what producer
intends to make. To define ripeness date it’s need to measure also total acidity
and pH. However, nowadays we have other methods more precise to
determinate different steps like date of harvest. For example remote detection is
a method who permit determine precise when to vintage. There are different
index that we can use to define date of harvest like Maturation Index or Baragiola
Index but using new technology like satellites or monitoring on vineyard with
sensors and cameras.
2. The harvest must be performed caste to caste. The grapes must have the
maturity required and must be harvested quickly. One way to determine more
precisely the date of harvest, and use the indexes or interpret the values found, is to
control ripening. From a sample to determine the concentration of various
constituents measurable grape. In doing so the grower can predict, within certain
limits, the date of harvest. This monitoring should be initiated during the maturation
phase with periodicity smaller, as it moves towards the end of this phase.
These controls allow you to follow the course of maturation. There are several types
of sampling:
- For strains;
- For cluster;
- For berry
Sampling should be carried out once a week, at the beginning of ripening, and
thereafter twice a week.
There is a heterogeneity of maturation in the parcel, on caste, vine and berry.
For that to be representative of the overall state of ripeness, must follow rules on
sampling.
In the sample of strains must be taken per plot four strains in 16 clusters of clusters,
and the berry, about 250 balls. This collection should be made a random order,
without choice, and may adopt a methodology of collection (every two lines, two
bunches per vine). Should follow some principles:
 alternation between clusters exposed to sun and shade;
 exclusion of borders
 vines or exclusion of patients with excessive force;
 Switching between internal and external face of the bunch;
 alternation between harvesting berries along the stem and at the end of the
bunch;
 exclusion of berries attacked rot.
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3. Ana Cristina Romão
3. Instead of using the cluster sampling and how to improve in terms of accuracy in
the representation of the population would use the sample per plot per berry. The
analytical technique of sample preparation is easier and the fact that not using ,
the stems. The collection is delayed but the representation is better ensured
when picking berries for sampling, in addition to greater ease of collection of the
sample in the field.
Problem B
1.
30
25
20
Tank 1
Tank 2
15 Tank 3
Tank 4
º Brix
Tank 5
10 Tank 6
Tank 7
Tank 8
5
0
11-Out
12-Out
13-Out
14-Out
15-Out
16-Out
17-Out
19-Out
20-Out
21-Out
22-Out
23-Out
24-Out
25-Out
26-Out
27-Out
28-Out
29-Out
30-Out
01-Nov
18-Out
31-Out
-5
2. Analyzing tables it appears that some tanks end early its fermentation. Others
have fermentation to finish later. Given that the addition of SO2 inhibits yeast,
causing a slight retarding of the fermentation and the addition of yeast allows
more rapid consumption of sugar, may be visible in the table the two. Moreover,
as there are only eight doses to be applied, there are two tanks, which was not
applied and yeast two tanks have had use of sulfur. The tanks 2 and 4 will have
taken over as the sulfur fermentation was slower which may be associated with
the fact that no taken yeast.
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4. Ana Cristina Romão
3. The Chardonnay is a grape varietal that is often used in the Champagne region.
The application of yeast EC1118, used for this type of wine leads to a better use
of this feature of this caste. In the case of tanks 5 and 7 should have been
applied to two doses of this yeast which allowed a more rapid fermentation (see
table) and a substantial improvement in sensory give the preference in terms of
proof.
4. The additional information that I need in order to better assess the situation at
MW Wines are:
Sales
Marketing and Advertising
Distribution
Contacts
Cost per liter of wine
Quality of grapes
Quality was
Producing areas and varieties used
5. I would recommend MW Wines institute to chance same procedures like to make
a Best Marketing Campaign, sponsorship of events such as International and
National level competitions (Golf, Sailing, Tennis, etc.).
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