2012 Crop Cerveza Malting and Brewing Trials - CMBTCcmbtc.com/.../11/2012-Crop-Cerveza-MB-Trials-2013.pdf · 2012 crop Cerveza barley samples exhibited very good extract yield and

2013

CMBTC

6/19/2013

2012 Crop Cerveza Malting and Brewing Trials

1365-303 Main Street • Winnipeg, Manitoba, Canada R3C 3G7 • Telephone 204-984-4399 • Fax 204-984-5843 Email [email protected] • Website www.cmbtc.com

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Report of the Malting and Brewing Trials with Cerveza 2012 Crop Barley Samples of Cerveza

Summary

CMBTC conducted pilot malting and pilot brewing trials on 2012 crop Cerveza barley samples, which were provided to CMBTC by Mastin Seeds of Sundre, Alberta. The objective of this study was to examine the malting and brewing performance of this newly developed 2-rowed Canadian malting variety. This is the second year of trials, with another report issued on 2011 crop Cerveza last year and available on the CMBTC website (www.cmbtc.com).

The Cerveza barley samples from 2012 harvest showed normal appearance and no noticeable signs of mould infection and/or serious staining. However, some significant quality differences between barley samples were recorded. The Cerveza barley samples showed acceptable grain moisture contents, good protein contents, very good thousand Kernel weight and very high plumpness. One Cerveza barley sample showed germination energy lower than that required for malting and the others showed good germination energy; all samples exhibited significant water sensitivity. In addition, the samples showed significant differences in RVA value; one had extremely low RVA values, which indicated poor storability, in contrast with others that showed high RVA values, which suggested good storability potential. In comparison with 2011 crop AC Metcalfe barley, on average 2012 crop Cerveza barley showed higher grain moisture, lower protein content, lower germination energy and stronger water sensitivity, as well as lower RVA values than 2012 crop AC Metcalfe. In the pilot malting trials, 2012 crop Cerveza barley samples did not exhibit any difficulties in processing. They showed good water-uptake and chitted well at steep, and recorded good growth of acrospires during germination. The malts produced from 2012 crop Cerveza showed satisfactory values in friability, extract yield, soluble protein, FAN, enzymes and malt color; although beta-glucan contents were higher than that required by brewers. Compared to the malts of 2012 crop AC Metcalfe, Cerveza malts showed higher friability; significantly higher extract yield, comparable soluble protein, comparable FAN levels, slightly higher color and significantly higher beta-glucan content. In addition, Cerveza malts showed comparable α-amylase, and lower diastatic power and limited dextrinase than AC Metcalfe. Please note that comments for dextrinase were based on limited data. The results generated from the pilot malting suggested that 2012 crop Cerveza barley can be processed under the normal processing conditions used for Canadian two-row malting barleys. However, in order to lower malt beta-glucan content and control malt


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color, the processing conditions that are known to affect malt beta-glucan content and color development should be closely monitored throughout the process. In the brewhouse, 2012 crop Cerveza recorded shorter average conversion time to the 2012 crop AC Metcalfe average. Time for wort to clear to less than 100 FTU in lautering was very good and was on average comparable to the averages of 2012 crop AC Metcalfe. Average lautering time for 2012 crop Cerveza was slightly longer than 2012 AC Metcalfe averages. Malt Material Yield was very good, and on average only slightly lower than the 2012 crop AC Metcalfe averages. Wort clarity and break in the wort kettle were good and comparable to the controls. The wort pH values were typical for the wort samples derived from barley malts, and only slightly lower than the averages of 2012 AC Metcalfe samples. Cerveza recorded somewhat lower average wort colour than the 2012 crop AC Metcalfe. Acceptable wort sugar spectrum was recorded for the average of 2012 crop Cerveza. The average fermentability of the worts produced from 2012 crop Cerveza was good and comparable to the average for 2012 crop AC Metcalfe. Cerveza malt produced beer with good quality. Apparent and real extracts were good and on average slightly higher than the 2012 AC Metcalfe controls, as well as the alcohol in final beer. Average beer colour for 2012 crop Cerveza samples was significantly lower than the control averages, while the final pH was slightly lower than 2012 AC Metcalfe controls. 2012 crop Cerveza beer had comparable foam stability to the averages of 2012 AC Metcalfe controls. The initial and chill turbidities were good. Cerveza beer had on average slightly lower body, comparable estery character, and was less sweet and sulphury than AC Metcalfe control.


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Overall Summary of Barley, Malting and Brewing Characteristics Of 2012 Cerveza versus 2012 AC Metcalfe

Cerveza Comparison to 2012 Crop AC

Metcalfe

Barley Analysis

Barley protein Desirably lower

Germination energy Lower

Water sensitivity Comparable

Water-uptake Comparable

Chitting Comparable

Acrospire growth Comparable

Malting Performance

Modification Comparable

Extract Significantly higher

α-amylase Comparable

Diastatic power Lower

Beta-glucan Higher

FAN level Comparable

Brewing Performance

Conversion time Faster

Lautering time Good

Extraction efficiency Good

Fermentability Good Green = better; Red = poorer; Yellow= comparable results


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1. Barley Quality Analysis When the 2012 crop Cerveza barley samples arrived at CMBTC, the quality was examined prior to pilot malting trials, and the test results are summarized in Table 1. Please note that all the testing results reported in Table 1 were generated from a single test except for the germination testing. The Cerveza barley samples from 2012 harvest all showed normal appearance and no noticeable signs of mould infection and/or serious staining. The Cerveza barley samples showed acceptable grain moisture contents and good protein contents. One Cerveza barley samples showed poor germination energy, which was lower than that required for malting use (≥95%) and the rest showed good germination energy. All samples showed significant water sensitivities. The Cerveza samples showed very good thousand Kernel weight and very high plumpness. In addition, the barley samples showed significant differences in RVA value; one had extremely low RVA values, which indicated poor storability, in contrast to others that recorded high RVA values, which suggested good storability. In comparison with 2011 crop AC Metcalfe barley, on average 2012 crop Cerveza barley showed significantly higher grain moisture, lower protein content, significantly lower germination energy and stronger water sensitivity. The Cerveza barley showed significantly higher thousand kernel weight, higher plumpness and lower RVA than 2012 crop AC Metcalfe.

Table 1. Analysis of 2012 crop Cerveza barley samples received at CMBTC

CMBTC Variety ID

Mo

istu

re, %

Pro

tein

, %

Ge

rmin

ati

on

,

% (

4m

l, n

=2

)

Ge

rmin

ati

on

,

% (

8m

l, n

=2

)

10

00

Ke

rne

l

wt,

g

Sizing, %

RV

A

>6

/64

sie

ve

>5

/64

sie

ve

Th

in

2012 crop Cerveza

B-12-197 12.6 12.7 93 66 43.2 91.2 6.8 1.5 17

B-12-198 11.7 10.5 98 83 51.3 98.1 1.7 0.1 128

Average 12.2 11.6 95.5 74.5 47.3 94.7 4.3 0.79 72.5

STD 0.45 1.1 2.5 8.5 4.05 3.47 2.53 0.69 55.5

2012 crop AC Metcalfe

Mean (n=16) 11.9 12.9 97.7 77.1 40.2 86.53 9.77 2.51 82


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2. Pilot Malting Trials

One pilot malt trial with a batch size of 55 kg cleaned barley was conducted on each of the 2012 crop Cerveza barley samples. All the malting trials were carried out with CMBTC’s pilot malting system using the processing conditions given in the box below.

Box 1. The processing conditions used for 2012 crop Cerveza pilot malting trials

SSTTEEEEPPIINNGG CCYYCCLLEESS

44 hours (8 hrs Wet- 12 hrs Dry- 9 hrs Wet -14 hrs Dry -1 hr Wet) at 14C

GGEERRMMIINNAATTIIOONN CCOONNDDIITTIIOONNSS

Day 1 & Day 2@ 15C, Day 3 & Day 4 @ 14C

KKIILLNNIINNGG CCOONNDDIITTIIOONNSS

A 21 hour cycle with a 4-hour curing phase at 82C

WWaatteerr uuppttaakkee,, cchhiittttiinngg aanndd aaccrroossppiirree ggrroowwtthh:: Under the given malting conditions, the Cerveza barley samples of 2012 crop did not exhibit any processing abnormalities. At steep they showed good water-uptake, and obtained satisfactory steep-out moisture contents and good chitting rates (Table 2); during germination Cerveza barley showed good growth of acrospires. In comparison with 2012 crop AC Metcalfe, Cerveza barley showed comparable water-uptake, a lower chitting rate and faster growth of acrospires than AC Metcalfe. Table 2. Steep-out moisture content, chitting rate and growth of acrospires Of 2012 crop Cerveza barley

Steep-

out Moisture

Chitting

rate Acrospire growth length @96 hrs

(%) (%) 0-¼ (%) ¼-½ (%) ½-¾ (%) ¾-1 (%) >1 (%)

2012 crop Cerveza

PM-13-001 44.7 95.0 0 0 0 50 50

PM-12-091 42.2 96.0 0 0 0 90 10

Mean 43.5 95.5 0 0 0 70 30


Mean 43.7 97.0 0 0 9.0 70.0 21

Complete malt analysis was carried out for these pilot malting trials, and the analytical results are given in Table 3. For comparison, the table also includes the average malt analysis of the malting trials carried out at CMBTC with 2012 crop AC Metcalfe barley samples. The figure below detail typical plots for germination and kilning.


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Table 3. Analysis of malts generated from the pilot malting trials of 2012 crop Cerveza

Parameter

2012 crop Cerveza


B-12-197 PM-13-001

B-12-198 PM-12-091

Mean Mean (n=16)

Malt moist, % 3.9 4.0 4.0 4.3

Friability, % 89.1 - 89.1 80.3

Fine-extract, % 81.6 83.5 82.6 80.7

Coarse-extract, % 81.0 82.2 81.6 79.7

F/C Difference, % 0.6 1.3 1.0 1.0

Soluble protein, % 6.29 4.53 5.41 5.40

Total protein, % 12.16 9.8 11.0 12.5

Kolbach Index, % 51.7 46.2 49.0 43.6

Beta-Glucan, ppm 107 273 190 155

Viscosity, cps 1.45 1.53 1.49 1.46

Diastatic power, L 145 129 137 158

-Amylase, D.U. 70.6 66.1 68.4 68.3 Limited Dextrinase, mu/g

317.0 414.2

Wort colour, ASBC 3.06 3.00 3.03 2.34 Wort pH 5.89 6.03 5.96 5.93 Fan, mg/L 235 180 208 203


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Malting Summary

General modification: The values for friability, F/C difference, and soluble protein content suggested that these 2012 crop Cerveza barley samples produced malts with good modification; however, the elevated malt beta-glucan contents in one sample indicated that attention must be paid when malting Cerveza to ensure proper modification and beta-glucan breakdown.

Extract yield and enzyme levels: The malts produced from 2012 crop Cerveza barley samples exhibited very good extract yield and adequate levels of enzymes. In comparison with the trial averages of 2012 crop AC Metcalfe, on average Cerveza

malts exhibited significantly higher extract yield; and its -amylase levels were similar to AC Metcalfe and its diastatic power levels were noticeably lower than AC Metcalfe. In addition, its limit dextrinase levels were lower than AC Metcalfe.

Soluble protein, free amino nitrogen (FAN) and malt colour: The malts produced from 2012 crop Cerveza barley samples exhibited good protein solubilisation. Compared to the trial averages of 2012 crop AC Metcalfe, Cerveza malts showed similar soluble protein but higher Kolbach Index. Cerveza malts developed adequate levels of FAN, which were comparable to AC Metcalfe. Cerveza malts developed good color, which was significantly higher than AC Metcalfe.

Beta-glucan content and wort viscosity: 2012 crop Cerveza barley showed slower beta-glucan breakdown and significant differences in beta-glucan content between the barley samples were recorded. However, wort viscosity for the two samples was within the acceptable range.


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CCoommmmeennttss oonn tthhee mmaallttiinngg pprroocceessss During the malting process, no difficulties were recorded for the 2012 crop Cerveza barley samples. The barley samples were processed under the processing conditions used for quality evaluation of Canadian two-rowed malting barley varieties.

At steeping, target a steep-out moisture content of 44-45% and an over 85% chitting rate. The steeping cycle should consist of 2 or 3 wet periods at 14-16°C. In germination avoid high temperature and excessive watering to control the growth of acrospires and protein breakdown. In kilning a lower curing temperature (80-82°C) should be considered to avoid excessive malt color formation.

3. Pilot-brewing Trials Cerveza malt samples from the pilot malting trials were brewed in CMBTCs 300L Pilot Brewery. The following are the brewing and fermentation conditions for the brewing trials with the Cerveza malt samples. Four of the seven brewing trials were discarded after brewing and only overnight fermentation was conducted, while other three samples were fermented and final beer was analyzed. Mash Tun

100% malt brew – 40 kg of malt and 150L of water added to mash tun

Mash in at 48C, hold for 30 min

Raise to 65C, hold for 30 min

Raise to 76C

Pump over to Lauter Tun Lauter Tun

Rest for 10 minutes, vorlauf for 10 minutes

Rakes at 20 cm above bottom, on slow for entire lautering

25L underlet

125L sparge water at 75C Brew Kettle

First hop (Nugget) boiled for 90 min – 45g

Second hop (Mt. Hood) boiled for 5 min – 90g


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Fermentation, aging, filtering and bottling conditions for the brewing trials

Cooled to 13.5ºC, pitched with lager yeast at 1.25 million cells per mL

Fermented for 7 days (3 days at 13.5ºC and 4 days at 15ºC)

Cooled and stored at -0.5 ºC for 7 days

Filtered through a 1 µm pad filter system, carbonated to 2.5 volumes CO2

Stored 2 days at -2oC, and packaged

Pasteurized to 15 PU

Figures 1 through 4 detail one of the brewing trials with Cerveza malt sample.

Figure 1: Mash Temperature Profile (temperature versus time)


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Figure 2: Runoff Turbidity (turbidity FTU versus time)

Figure 3: Runoff Specific Gravity (°Plato versus time)


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Figure 4: Runoff Flowrate (l/minute versus time) The brewing results are given in Tables 4 to 8. Tables also contain average values for 2012 crop AC Metcalfe trials for comparison.

Table 4. Main Brewhouse observations for pilot brewing trials

Parameter Cerveza Trial 1

Cerveza Trial 2

Cerveza Trial 3

Cerveza Trial 4

Cerveza Trial 5

Cerveza Trial 6

Cerveza Trial 7

Cerveza 2012 Mean

AC Metcalfe

2012 Mean

Conversion time (min.) 21 10 11 13 10 20 8 13.3 16.8

Time to clear (min.) 5 8 7 6 7 6 7 6.6 6.6

Lautering time (min.) 39 43 40 40 41 42 38 40.4 39.4

Malt Material Yield (%) 89.5 88.4 87.4 87.2 88.7 90.5 89.1 88.7 89.0

Wort pH 5.29 4.97 5.03 5.28 5.38 5.04 5.23 5.17 5.20

Wort Colour (SRM) 4.37 3.57 2.74 3.36 5.03 3.11 3.13 3.62 4.72

In the brewhouse, 2012 crop Cerveza recorded shorter average conversion time to the 2012 crop AC Metcalfe average. Conversion time ranged from 8 minutes in Trial 7 to 21 minutes in Trial 1. Conversion time is a metric that is important for the brewer in regards


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to the economics of his brewhouse. Longer conversion times could translate into higher operating costs in more energy requirement, higher labour costs or decreased capacity. Conversion time is related to the enzyme content of the malt, and can be manipulated by changing malt: water ratio and temperature.

Time for wort to clear to less than 100 FTU in lautering was very good (ranging from 5 to 8 minutes), and was on average comparable to the averages of 2012 crop AC Metcalfe. Time required for the wort to clear is a metric that is important for the brewer in regards to the economics of his brewhouse as well as the quality of the finished beer. Most brewers want clear wort, which provides better quality beer and also allows for better capacity utilization in fermentation. The time to obtain wort that is clear (less than 100 FTU) is therefore related to capacity and manpower utilization. Average lautering time for 2012 crop Cerveza was slightly longer than 2012 AC Metcalfe averages. Lautering time ranged from 38 minutes in Trial 7 to 43 minutes in Trial 2. Time to complete the runoff is a metric that is important for the brewer in regards to the economics of his brewhouse. Longer times could translate into higher operating costs in more energy requirement, higher labour costs or decreased capacity. Runoff time is related to the beta-glucan content of the malt as well as the friability and milling of the malt. Malt Material Yield was very good, and on average only slightly lower than the 2012 crop AC Metcalfe averages. Malt Material Yield ranged from 87.2 in Trial 4 to 90.5 in Trial 6. Malt Material Yield shows the percentage of the extract that was recovered into the cast wort. It is a measure of how easily the extract is recovered from the malt. Wort clarity and break in the wort kettle were good and comparable to the controls. Wort clarity and good protein precipitation is related to improved colloidal stability of the final product. The wort pH values were typical for the wort samples derived from barley malts, and only slightly lower than the averages of 2012 AC Metcalfe samples. Wort pH is related to beer flavour stability, the higher the pH the more flavour stable the beer is through time. However, the pH cannot be too high or else the possibility of flavour changes increases and microbiological infection can occur. Cerveza recorded somewhat lower average wort colour than the 2012 crop AC Metcalfe. Only one Cerveza wort sample (Trial 5) had higher colour than the AC Metcalfe average. Wort colour is positively correlated to the barley protein content, as well as malt colour and malting processing conditions. Most international brewers are looking for a lower pale colour to be derived from the malt, so the lower the better. Wort taste was acceptable. This is a quick test to look for off-flavours. The wort should be malty, sweet with no off-flavours.


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Table 5. Wort sugar concentration for the brewing trials (mg/L)


Cerveza Trial 2

Cerveza Trial 3

Cerveza Trial 4

Cerveza Trial 5

Cerveza Trial 6

Cerveza Trial 7

Cerveza 2012 Mean

AC Metcalfe

2012 Mean

Maltotetrose 3.51 3.00 2.83 3.19 3.21 2.45 3.15 3.05 2.81

Maltotriose 16.74 12.74 13.64 14.72 15.45 14.66 15.69 14.81 14.63

Maltose 57.88 56.75 55.02 61.67 56.50 60.67 61.19 58.52 58.09

Glucose 17.35 13.72 13.15 14.19 15.42 14.72 15.45 14.86 14.96

Fructose 5.64 2.68 2.27 2.87 3.19 2.72 1.96 3.05 3.15

Acceptable wort sugar spectrum was recorded for the average of 2012 crop Cerveza (Table 5). It had generally comparable both unfermentable and fermentable sugars to the averages of 2012 crop AC Metcalfe.

Table 6. Fermentation observations for the brewing trials


Cerveza Trial 2

Cerveza Trial 3

Cerveza Trial 4

Cerveza Trial 5

Cerveza Trial 6

Cerveza Trial 7

Cerveza 2012 Mean

AC Metcalfe

2012 Mean

Attenuation Limit (%) 89.06 82.62 85.22 85.82 89.66 87.39 87.64 86.77 86.88

The average fermentability of the worts produced from 2012 crop Cerveza (Table 6) was good and comparable to the average for 2012 crop AC Metcalfe. Only one sample (Trial 2) had somewhat lover fermentability than 2012 AC Metcalfe crop average. Fermentability is important in that it is a measure of the amount of beer that can be produced from the original malt. The higher the fermentability the better.


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Table 7. Final beer analysis for the brewing trials


Cerveza Trial 2

Cerveza Trial 3

Cerveza 2012 Mean

AC Metcalfe

2012 Mean

Apparent Ext. (Plato) 1.44 2.01 1.79 1.75 1.56

Real Ext. (Plato) 3.35 3.93 3.56 3.61 3.39

Alcohol (v/v %) 5.25 5.33 4.83 5.14 5.00

Color (ASBC) 4.21 2.17 1.94 2.77 5.27

pH 4.49 3.9 4.07 4.15 4.33

Foam (Nibem) 142 134 154 143.3 140

Initial Turbidity (FTU) 14.5 12.2 15.03 13.9 20.0

Chill Turbidity (FTU) 24 Hr 15.8 12.51 16.37 14.9 23.3

Cerveza malt produced beer with good quality. Apparent and real extracts were good and on average slightly higher than the 2012 AC Metcalfe controls, as well as the alcohol in final beer. Average beer colour for 2012 crop Cerveza samples was significantly lower than the control averages, while the final pH was slightly lower than 2012 AC Metcalfe controls. 2012 crop Cerveza beer had comparable foam stability to the averages of 2012 AC Metcalfe controls. The initial and chill turbidities were good, and lower than the controls, indicating good physical and colloidal stability. Average beer organoleptic data is presented in Table 8 and Figure 5. Cerveza beer had on average slightly lower body, comparable estery character, and was less sweet and sulphury than AC Metcalfe control.


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Table 8. Final beer organoleptic property data


Cerveza Trial 2

Cerveza Trial 3

Cerveza 2012 Mean

AC Metcalfe

2012 Mean

Freshness 2.23 2.36 2.63 2.41 2.63

Body 1.93 1.18 1.79 1.63 1.88

Flavour 1.93 1.18 1.58 1.57 2.15

Smoothness 2.60 2.71 2.33 2.55 2.30

Hop Aroma 1.53 0.64 1.29 1.16 1.18

Hop Bitterness 1.90 0.93 1.42 1.42 1.70

Estery 1.70 1.61 1.79 1.70 1.65

Cereal 1.70 1.21 1.42 1.44 1.96

Turbidity 0.80 0.61 0.75 0.72 0.97

Sour 1.40 0.96 1.17 1.18 1.38

Sweet 1.47 1.00 1.17 1.21 1.32

Sulphury 0.93 0.36 0.67 0.65 1.06

Overall Quality 2.50 2.64 2.29 2.48 2.28

Quality scale 0 – Undrinkable 1 – Defects at high level (consumer would notice) 2 – Slight defects (expert would object, typical slightly aged market beer) 3 – Normal good beer (nothing really good or bad, reasonably fresh) 4 – Excellent (no real defects and many good characters) Additional Terms Rating Scale 0 – Non existent 1 – Light, faint 2 – Mild 3 – Very noticeable 4 – Very strong


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Figure 5. Final beer organoleptic property data

For more information, please contact CMBTC: Rob McCaig, Managing Director and Director of Brewing Tel: (204) 983-1981 Email: [email protected] Yueshu Li, Director of Malting Technology Tel: (204) 984-0561 Email: [email protected] Fax 204-984-5843

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2012 Crop Cerveza Malting and Brewing Trials - CMBTCcmbtc.com/.../11/2012-Crop-Cerveza-MB-Trials-2013.pdf · 2012 crop Cerveza barley samples exhibited very good extract yield and