2012 Malting and Brewing Trials with 2011 Crop Barley Samples of and 7/10/2012
Malting and Brewing Trials with 2011 Crop Barley Samples of and Summary Pilot malting and brewing trials were conducted at CMBTC on each of the two and two barley samples provided to CMBTC by Prairie Malt Limited. These barley samples were collected at two Saskatchewan growing sites located in Plenty and Direct during 2011 harvest. The objective of this study was to examine malting and brewing performances of the newly harvested barley against the control. All the malting and brewing trials were conducted using the processing conditions developed at CMBTC for evaluating new crop barley samples. The observed important differences between and in barley quality, malting and brewing performances are summarized in the box below: Quality parameter 2011 2011 Control Barley quality Barley protein Very desirable Very desirable Germination energy Acceptable Very good Water sensitivity Strong Light Water uptake Rapid Rapid Chitting Excellent Excellent Acrospire growth Good Good Malting performance Modification Very Good Very Good Extract Good but lower High α-amylase Lower High Diastatic power Higher High Beta-glucan Goog but higher Low FAN level Adequate but lower Adequate Brewing performance Conversion time Moderate Moderate Lautering time Good Good Extraction efficiency Very Good Good Fermentability Higher High Green = better than control; Red = poorer than control; Yellow= comparable results and 2011 crop barley samples from these two growing locations all showed acceptable moisture contents and desirable protein contents.
However, some significant differences in germination energy, water sensitivity, thousand kernel weight and plumpness between varieties and between growing locations were recorded. from Plenty showed undesirable germination energy (lower than the required 95%) and strong water sensitivity, while it had very good thousand kernel weight and good plumpness. In contrast, from Direct showed excellent germination energy, stronger water sensitivity and good thousand kernel weight. In the malting trials, under the given malting trial conditions, the two barley samples from Plenty and Direct did not show any processing difficulties. In both trials barley produced malts with satisfactory quality. No significant differences in malt quality between the two growth locations were recorded. In the brewhouse, samples recorded comparable metrics to malts. had on average somewhat higher fermentability than the averages of samples. Two samples were bottled and they produced beers with good quality. In terms of sensory, the beers received comparable marks to the control averages.
Location Moisture % Protein % Germination, % (3 day, 4ml) Germination, % (3 day, 8ml) 1000 Kernel wt., g Over 6/64 sieve,% Over 5/64 sieve,% Thru, % 1. Barley analysis When barley samples of and AC Metcalf arrived at CMBTC, their quality was examined immediately, and the test results are given in Table 1. Please note that all the test results reported in Table 1 were generated from a single test except for the germination testing. Table 1. Analysis of 2011 crop barley samples of and the control from Saskatchewan Barley ID B-11-234 Plenty 12.3 10.9 89.5 72 46.1 94.4 3.62 1.65 B-11-233 Direct 11.5 11.9 99.5 66 42.6 83.5 5.70 11.0 11.9 11.4 94.5 69.0 44.4 88.9 4.66 6.33 B-11-232 Plenty 11.5 11.2 98.5 91.0 45.4 94.2 3.13 0.93 B-11-235 Direct 12.4 10.6 99.5 90.5 46.1 93.4 4.22 1.25 12.0 10.9 99.0 90.8 45.8 93.8 3.68 1.09 The routine barley testing indicated that and barley samples from the two growing locations all showed acceptable moisture contents and desirable protein contents. However, some significant differences between varieties and between growing locations in germination energy, water sensitivity, thousand kernel weight and plumpness were recorded. from Plenty showed undesirable germination energy (lower than the required 95% for malting) and strong water sensitivity, but it showed very good thousand kernel weight and plumpness. Its thousand kernel weight and plumpness were comparable to the control. from Direct showed excellent germination energy and much stronger water sensitivity. Its thousand kernel weight was good, but its plumpness was undesirably low. from Direct showed the lowest plumpness among the four barley samples. In comparison with the control, showed on average lower germination energy, stronger water sensitivity, slightly lower thousand kernel weight and significantly lower plumpness.
2. Pilot malting trials Pilot-malting trials were conducted on the four barley samples under the processing conditions given in Box 1 using the pilot malting system at CMBTC. In the trials, different steeping conditions were applied to and respectively, while both varieties were germinated and kilned under identical conditions. Box 1. Processing conditions for the pilot malting trials STEEPING CYCLE 41 hours (7 Wet-13 Dry- 8 Wet-12 Dry- 1 Wet) at 14 C 44 hours (8 Wet-12 Dry- 9 Wet-14Dry- 1 Wet) at 14 C GERMINATION CONDITIONS Day 1 & Day 2 @ 15 C; Day 3 and Day 4 @ 14 C KILNING CONDITIONS A 24 hour cycle with a 4-hour curing phase at 82 C Water uptake, chitting and acrospires growth: In the malting trials, under the given malting conditions, barley obtained satisfactory steep-out moisture content and excellent chitting rates at the end of steep (Table 2). On average, showed water-uptake comparable to the control. However, please note that since and used different steeping cycles, the varietal difference in water uptake between these two barley varieties could be due to the differences in steeping conditions. During germination, showed good acrospires growth, but its overall growth was slower than the control (Table 2).
Steep-out moisture, % Chitting rate,% Table 2. Steep-out moisture content, chitting rate, and acrospire growth profile for 2011 crop and control barleys from Saskatchewan Sample and trial ID 0-¼ (%) ¼-½ (%) ½-¾ (%) ¾-1 (%) >1 (%) PM-11-087 Plenty/B-11-234 44.9 100 0 0 25 55 20 PM-11-088 Direct/B-11-233 44.5 100 0 5 25 40 30 44.7 100 0 2.5 25 47.5 25 PM-11-086 Plenty/B-11-232 44.9 100 0 0 0 55 45 PM-11-090 Direct /B-11-235 43.6 100 0 0 30 55 15 44.2 100 0 0 15 55 30
Complete malt analysis was carried-out for the malts produced in the pilot malting trials (Table 3). Table 3. Malt analysis for 2011 crop barley samples of and AC Metcalfe grown in Plenty and Direct of Saskatchewan PM-11-087 PM-11-088 PM-11-086 AC Metcalfe PM-11-090 AC Metcalfe Malt moisture, % 3.8 4.1 4.0 3.8 4.0 3.9 Friability, % 86.8 87.6 87.2 92.5 92.4 92.5 Fine-extract, % 81.7 81.8 81.8 82.4 83.1 82.8 Coarse-extract, % 80.8 80.8 80.8 81.8 82.5 82.2 F/C Difference, % 0.9 1.0 1.0 0.6 0.6 0.6 Soluble protein, % 5.21 5.49 5.35 5.48 5.29 5.39 Total protein, % 11.7 12.0 11.9 11.2 10.6 10.9 Kolbach Index, % 44.4 45.9 45.2 49.2 49.9 49.6 β-glucan, ppm 136 67 102 72 87 80 Viscosity, cps 1.47 1.44 1.46 1.44 1.45 1.45 Diastatic power, L 135 168 152 140 140 140 -Amylase, D.U. 53.4 67.8 60.6 66.3 69.5 67.9 Wort colour, asbc 2.26 2.41 2.34 2.18 2.24 2.21 Wort ph 5.95 5.94 5.95 5.89 5.99 5.94 Fan, mg/l 177 196 187 207 204 206 Overall modification: The values for friability, F/C difference, soluble protein and betaglucan content (Table 3) all indicated that and barley samples produced quality malts in the pilot malting trials. s overall modification was comparable to s. Extract yield and enzyme levels: The malts produced from 2011 crop and barley samples from both growing locations exhibited very good extract yield. On average the extract yield for was slightly lower than the control. malts developed good levels of enzymes. Its alphaamylase levels were lower than the control while its diastatic power levels were significantly higher than the control. Soluble protein, free amino nitrogen (FAN) and malt colour: The malts produced from 2011 crop and barley samples from both growing locations exhibited good protein solubilisation as indicated by soluble protein, KI and
FAN. On average, s soluble protein content was comparable to the control, while its KI and FAN were lower than the control. malts developed acceptable malt color, which was slightly higher than the control AC Metcalfe. Overall comments: Under the given trial malting conditions, the two barley samples from Plenty and Direct did not show any processing difficulties in the malting trials. In both trials barley produced malts with satisfactory quality. No significant differences in malt quality between the two growth locations were recorded, though the malt produced from Plenty sample showed higher β-glucan content than Direct sample. In comparison with the control, malts showed comparable overall quality. However, s friability, extract yield, KI and FAN were lower, while its β-glucan was higher. Its enzymes and color were good, and were comparable to in general.
3. Brewing trials and malt samples from the pilot malting trials were brewed in CMBTCs 300L Pilot Brewery. Only malts from two brewing trials were fermented and final beer was bottled. malts were brewed and only overnight fast fermentation was performed. The following are the general brewing and fermentation conditions for the brewing trials with and sample malts. The final beer results for the pilot malted samples represent the averages of that variety for 2011 crop year. BREWING PARAMETERS: Mash Tun 100% malt brew 40 kg of malt and 150L of water added to mash tun Mash in at 48 C, hold for 30 min Raise to 65 C, hold for 30 min Raise to 76 C 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 75 C Brew Kettle First hop (Nugget) boiled for 90 min 37g Second hop (Mt. Hood) boiled for 5 min 75g 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 CO 2 Stored 2 days at -2 o C, and packaged Pasteurized to 15 PU Figures 1 through 4 detail the brewing process with the first (PB-11-104) sample.
Figure 1: Mash Temperature Profile for Trial 1 with (temperature versus time) Figure 2: Runoff Turbidity for Trial 1 with (turbidity FTU versus time)
Figure 3: Runoff Specific Gravity for Trial 1 with ( o Plato versus time) Figure 4: Runoff Flowrate for Trial 1 (l/minute versus time)
The brewing results are given in Tables 4, 5, 6, 7 and 8. Table 4. Main Brewhouse observations for pilot brewing trials Parameter (PM-11-087) (PB-11-104) (PM-11-088) (PB-11-100) (PM-11-086) (PB-11-094) (PM-11-090) (PB-11-097) Conversion time (min.) 12 10 11 13 10 11.5 Time to clear (min.) 8 9 8.5 7 6 6.5 Lautering time (min.) 38 35 36.5 34 40 37 Malt Material Yield (%) 89.4 89.8 89.6 88.7 88.6 88.65 Wort ph 5.04 5.10 5.07 5.12 5.09 5.11 Wort Colour (SRM) 3.16 3.59 3.37 3.60 3.15 3.38 In the brewhouse, samples recorded comparable conversion time to AC Metcalfe malts. Conversion time is a metric that is important for the brewer in regards 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. samples had on average somewhat longer time to clear (8.5 minutes) when compared to averages (6.5 minutes). 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, it 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. The average lautering time for malts was also comparable to AC Metcalfe averages. 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. malts had on average slightly higher Malt Material Yields than the averages of malt samples. 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 acceptable for all the samples. Wort clarity and good protein precipitation is related to improved colloidal stability of the final product. The wort ph values for all samples were typical for the wort derived from barley malts. In general samples showed somewhat lower ph values from 2011 AC Metcalfe wort averages. 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 and microbiological infection can occur. recorded a comparable average wort colour to averages. 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. Table 5. Wort sugar concentration for the brewing trials (mg/l) Parameter (PM-11-087) (PB-11-104) (PM-11-088) (PB-11-100) (PM-11-086) (PB-11-094) (PM-11-090) (PB-11-097) Maltotetrose 3.26 2.84 3.05 3.35 3.10 3.22 Maltotriose 15.10 12.99 14.04 14.48 14.10 14.29 Maltose 59.07 53.13 56.10 55.11 56.76 55.93 Glucose 14.17 12.51 13.34 14.50 13.94 14.22 Fructose 2.15 2.90 2.52 2.57 2.18 2.37 Acceptable wort sugar spectrums were recorded for all wort samples (Table 5). samples had on average somewhat higher levels of Maltose and Fructose, and slightly lower levels of Glucose, Maltotetrose and Maltotriose when compared to AC Metcalfe worts. Table 6. Fermentation observations for the brewing trials Parameter (PM-11-087) (PB-11-104) (PM-11-088) (PB-11-100) (PM-11-086) (PB-11-094) (PM-11-090) (PB-11-097) Attenuation Limit (%) 87.12 87.36 87.24 85.86 85.86 85.86
Fermentabilty of all the wort samples were acceptable (Table 6). had on average higher fermentability than the averages of samples. 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. Table 7. Final beer analysis for the brewing trials Parameter (PM-11-087) (PB-11-104) (PM-11-088) (PB-11-100) CMBTC Metcalfe 2011 Apparent Ext. (Plato) 1.49 1.45 1.47 1.74 Real Ext. (Plato) 3.50 3.44 3.47 3.64 Alcohol (v/v %) 5.55 5.47 5.51 5.24 Color (ASBC) 2.67 2.78 2.72 2.67 ph 4.16 4.17 4.16 4.53 Foam (Nibem) 227 198 212.5 209 Initial Turbidity (FTU) 15.4 17.2 16.3 13.9 Chill Turbidity (FTU) 24 Hr 16.8 18.2 17.5 15.2 Two samples were bottled and they produced beers with good quality. The final beer results for the pilot malted samples represent the averages of that variety for 2011 crop year. Apparent and real extract were both slightly lower, while final beer alcohol in beers was somewhat higher than the averages of 2011 beers. Average final beer colour for samples was only slightly higher than the average beer colour readings. average had somewhat higher ph readings when compared to products. beer samples had somewhat higher average foam stability than 2011 averages, and both values can be considered as very good. The initial and chill turbidity for beers indicated acceptable physical and colloidal stability, although averages had slightly lower haze readings. In terms of sensory, the beers received comparable marks to the control averages, and were rated as normal good beers with no defects and some good characteristics. Beer sensory data is presented in Table 8.
Table 8. Final beer organoleptic property data Quality Parameter (PM-11-087) (PB-11-104) (PM-11-088) (PB-11-100) Freshness 2.1 3.0 2.6 Body 1.7 2.0 1.9 Flavour 2.2 2.4 2.3 Palate 2.3 2.1 2.2 Hop Aroma 0.9 0.9 0.9 Hop Bitterness 1.3 1.3 1.3 Estery 1.7 4.1 2.9 Cereal 1.7 1.8 1.8 Turbidity 0.3 0.3 0.3 Sour 1.8 1.6 1.7 Sweet 1.5 0.8 1.2 Sulphury 0.8 0.5 0.7 Overall Quality 2.7 2.4 2.5 Additional Terms Diacetyl 0.5 0.5 0.5 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
Figure 5: Spiderplot of the Sensory Evaluation Overall Quality Sulphury Sweet Sour Freshness 4.5 4 3.5 3 2.5 2 1.5 1 0.5 0 Body Flavour Palate Hop Aroma (PM-11-087) (PB-11-104) (PM-11-088) (PB-11-100) Turbidity Hop Bitterness Cereal Estery In comparing the two beers sensory profiles (Figure 5) both beers very similar, although PB-11-100 displayed a higher estery character that the first Polarstar brew. For more information, please contact CMBTC: Rob McCaig, Managing Director and Director of Brewing Tel: (204) 983-1981 Email: rmccaig@cmbtc.com Yueshu Li, Director of Malting Technology Tel: (204) 984-0561 Email: yli@cmbtc.com Fax 204-984-5843 Website www.cmbtc.com