2012 Pilot Malting and Brewing Trials with 2011 Crop Barley 7/5/2012
Pilot Malting and Brewing Trails with 2011 Crop Samples of Barley Executive summary CMBTC conducted several pilot malting and brewing trials on 2011 crop barley samples, which were provided to CMBTC by Richardson International and the Crop Development Centre, University of Saskatchewan. The objective of conducting these trials was to examine malting and brewing performances of 2011 crop samples of barley under the processing conditions that are used at CMBTC for evaluating new crop barley samples. In this study, malting and brewing performances of barley were compared with the trial average of 2011 crop AC Metcalfe barley. The important quality differences between these two varieties recorded in malting and brewing are summarized in the table below. Quality attributes 2011 2011 AC Metcalfe Malting Water uptake Rapid Fast Extract yield High High Process time Short Short Enzymes Moderate High FAN Moderate-high High Colour Moderate Moderate Brewing Conversion time Moderate Moderate Lautering time Fast Fast Extraction Efficiency Good Good Fermentability High High Final beer colour Higher Moderate Final beer foam Good Very Good Green = better than control; Red = poorer than control; Yellow= comparable results 2011 crop samples showed good overall barley quality as indicated by good values in grain moisture, protein content, germination, thousand kernel weight and plumpness, although the quality varied from sample to sample. Limited RVA test results indicated that good storability can be expected for 2011 crop barley. Under the given pilot malting conditions, 2011 crop barley did not show any processing difficulties. barley produced malts with satisfactory quality. s overall malting performance was in general comparable to AC Metcalfe barley. However, its enzymes and FAN were lower, while beta-glucan content was higher than AC Metcalfe s average. 2
In the brewhouse, samples recorded on average somewhat longer conversion time than AC Metcalfe averages. That was to be expected since average enzyme levels in samples were lower than the average enzyme levels in AC Metcalfe. AC Metcalfe malt samples had conversion times ranging between 10 and 25 minutes, with 13 minutes being the average. Time for wort to clear to less than 100 FTU in lautering was longer than 10 minutes only for the third sample (PB-11-111). Therefore, Vorlauf time had to be extended from the regular 10 minutes to 12 minutes for that trial. samples required, on average somewhat longer time to clear in lautering (8 minutes) when compared to AC Metcalfe averages (6 minutes). The average lautering time for malts was slightly shorter than for 2011 AC Metcalfe averages. malts had on average comparable Malt Material Yields to the averages of 2011 AC Metcalfe malt samples. Wort clarity and break in the wort kettle were acceptable for all the samples. In general samples showed somewhat lower ph values from 2011 AC Metcalfe wort averages. recorded an average wort colour somewhat higher than the 2011 crop AC Metcalfe averages. Wort taste was acceptable. Acceptable wort sugar spectrums were recorded for all wort samples. samples had on average somewhat lower levels of Maltose and Glucose, and slightly higher levels of Fructose, Maltotetrose and Maltotriose when compared to AC Metcalfe worts. Fermantabilty of all the wort samples were acceptable. had on average slightly higher fermentability than the averages of 2011 AC Metcalfe. Three samples were bottled and they produced beers with good quality. Apparent and real extract, as well as final beer alcohol in beers were all comparable to the averages of 2011 AC Metcalfe beers. Average final beer colour for samples was slightly higher than the average AC Metcalfe beer colour readings. AC Metcalfe average had somewhat higher ph readings when compared to products. beer samples had somewhat lower average foam stability than 2011 AC Metcalfe averages, and both values can be considered as good. The initial and chill turbidity for beers indicated acceptable physical and colloidal stability, although AC Metcalfe averages had lower haze readings. In terms of sensory, the beers received comparable marks to the control AC Metcalfe averages, and were rated as normal good beers with no defects and some good characteristics. 3
Sample ID Moisture,% Protein, % Germ. Energy (72 hours), % Water sensitivity, % Thousand Kernel weight, g Plumpness (above 2.38 mm) % Over 5/64 (above 1.98 mm) % Thins (below 1.98 mm) % RVA 1. Barley analysis When these barley samples arrived at CMBTC, the quality of the barley was examined immediately. The test results are given in Table 1. Please note that except for the germination testing all the results reported in Table 1 were generated from a single test only. Table 1. Analysis of 2011 crop barley samples B-11-173 11.1 11.0 100 95.0 44.4 91.3 6.45 1.65 - B-11-231 10.6 9.8 100 95.0 45.5 94.5 3.97 0.98 - B-11-240 12.1 12.2 100 95.0 53.8 99.7 0.23 0.01 177 B-11-277 12.6 10.9 99 94.5 47.8 98.0 3.37 10.1 - Mean 11.6 11.0 99.8 94.9 47.9 95.9 3.51 3.19 177 Comments: 2011 crop barley samples included in this study all showed good overall barley quality, though the quality varied from sample to sample. All samples showed good grain moisture contents and desirable protein contents. Germination energy was excellent with negligible level of water sensitivity. Thousand kernel weight and plumpness were excellent. RVA value for sample B-11-240 indicated that good storability can be expected for 2011 crop, though RVA test was not carried out for all the samples listed in the table. 4
2. Pilot malting trial Four pilot malting trials, each with batch size of 55 kg cleaned barley, were conducted on the barley samples under CMBTC standard malting conditions, which simulated the processing employed in commercial malting. The malting conditions and observation comments for the pilot malting trials are detained in Box 1. Box 1. Details of the pilot malting conditions STEEPING CYCLES Total 40 hrs (8hrs Wet- 13hrs Dry- 8hrs Wet- 10hrs Dry- 1hr Wet)@14ºC Showed good water uptake and obtained very good chitting rate. GERMINATION CONDITIONS Day 1 & Day 2 @15 C; Day 3 & Day 4 @14 C Showed good growth and modification advancement during germination. KILNING CONDITIONS A 21 hour cycle with a 4-hour curing phase at 82 C Table 2. Steep-out moisture, chitting rate and acrospire growth profile of 2011 crop Malting ID End of steep Growth @96hr Moist Chitting ¼-½ ½-¾ 0-¼ (%),%,% (%) (%) ¾-1 (%) >1 (%) PM-11-060 45.5 95 0 0 30 50 20 PM-11-076 41.6 100 0 0 0 90 10 PM-11-100 41.3 100 0 0 45 40 15 PM-12-007 43.8 100 0 0 0 95 5 In the malting trials, under the given trial malting conditions, at the end of steep barley samples showed good water uptake and obtained satisfactory steep-out moisture contents and very good chitting rates (>85%). During germination barley showed good growth of acrospires and advancement in modification, although some variations between the samples in acrospire growth were recorded. Please note that for trials PM-11-076 and PM-11-100, the barley was steeped with a shorter steep cycle and the steep-out moisture contents were lower than those obtained in a regular steep cycle. In order to achieve normal growth and modification, the green 5
PM-11-076 B-11-277 PM-11-100 B-11-231 PM-12-007 B-11-240 PM-11-060 B-11-173 malts in those two trials were watered on day one and day two of germination to increase the green malt moisture content. 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 analysis of AC Metcalfe malts of 2011 crop. Table 3. Malt analysis for and AC Metcalfe Parameter 2011 2011 AC Metcalfe Mean Mean Malt moisture, % 3.9 4.2 4.4 4.1 4.2 4.1 Friability, % 85.8 83.5 82.5 85.4 84.3 85.2 Fine-extract, % 81.5 82.7 81.4 81.9 81.9 81.8 Coarse-extract, % 80.9 81.7 80.7 80.8 81.0 81.1 F/C Difference, % 0.6 1.0 0.7 1.1 0.9 0.7 Soluble protein, % 4.85 4.77 5.13 5.65 5.10 5.36 Total protein, % 10.1 10.5 12.03 10.84 10.9 11.5 Kolbach Index, % 47.9 45.2 42.6 52.1 47.0 46.5 Beta-Glucan, ppm 178 227 173 106 171 109 Viscosity, cps 1.48 1.46 1.37 1.43 1.44 1.46 Diastatic power, L 115 131 152 137 134 151 -Amylase, D.U. 47.6 53.9 55.7 53.1 52.6 65.0 Wort colour, ASBC 2.06 2.22 2.40 2.83 2.38 2.13 Wort ph 5.98 6.00 5.94 5.88 5.95 5.96 Fan, mg/l 155 167 195 199 179 199 Malting Summary Overall modification: The values for friability, F/C difference and soluble protein all suggested that under the given trial malting conditions all four barley samples produced malts with satisfactory modification. However, the elevated malt β-glucan content for trials of PM-11-76, PM-11-100 and PM-12-007 indicated that some further modification was needed to lower malt β-glucan content (Table 3). On average, s malt β-glucan content was higher than the trial average of AC Metcalfe. 6
Extract yield and enzyme levels: The malts produced in the pilot malting trials showed very good extract yield. On average s extract yield was comparable to 2011 AC Metcalfe. All malts developed good levels of enzymes, but their diastatic power and -Amylase levels were significantly lower than 2011 crop AC Metcalfe. Soluble protein, free amino nitrogen (FAN) and malt colour: The malts produced from 2011 crop barley samples exhibited good protein modification, and the KI was on average comparable to 2011 AC Metcalfe. malts developed adequate levels of FAN, but the FAN levels were significantly lower than 2011 AC Metcalfe. The malt color for malts was good and the color was comparable to AC Metcalfe. Overall comments: Under the given trial malting conditions, these four barley samples from 2011 harvest did not show any processing difficulties. barley produced malts with satisfactory quality. In comparison with AC Metcalfe, malts showed comparable friability, extract yield and similar soluble protein. However, malts showed significantly lower values in enzymes and FAN, and higher values in β-glucan. 7
3. Pilot Brewing trials malt samples from the pilot malting trials were brewed in CMBTCs 300L Pilot Brewery. Only the malt from three brewing trials with were fully fermented and aged until bottling. In the second brewing trial (PB-11-077), malt was brewed and only overnight fast fermentation was performed. The following are the general brewing and fermentation conditions for the brewing trials with sample malts. The brewing results for the pilot malted AC Metcalfe 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 8
Figures 1 through 4 detail the brewing process with the first sample. Figure 1: Mash Temperature Profile for Trial 1 (temperature versus time) Figure 2: Runoff Turbidity for Trial 1 (turbidity FTU versus time) 9
Figure 3: Runoff Specific Gravity for Trial 1 ( o Plato versus time) Figure 4: Runoff Flowrate for Trial 1 (l/minute versus time) 10
The brewing results are given in Tables 4, 5, 6 and 7. Table 4. Main Brewhouse observations for pilot brewing trials Parameter (PM-11-060) (PB-11-054) (PM-11-076) (PB-11-077) (PM-11-100) (PB-11-111) (PM-12-007) (PB-12-010) Mean CMBTC Metcalfe 2011 Mean Conversion time (min.) 12 18 18 16 16 13 Time to clear (min.) 6 8 11 7 8 6 Lautering time (min.) - 37 35 38 36.7 38 Malt Material Yield (%) 90.2 91.2 88.9 87.6 89.5 89.0 Wort ph 5.45 5.25 5.05 5.28 5.25 5.30 Wort Colour (SRM) 4.66 4.47 3.86 4.09 4.27 3.31 In the brewhouse, samples recorded somewhat longer conversion time than AC Metcalfe averages. That was to be expected since average enzyme levels in samples were lower than the average enzyme levels in AC Metcalfe. Metcalfe malt samples had the conversion times ranging between 10 and 25 minutes, with 13 minutes being the average. 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. Time for wort to clear to less than 100 FTU in lautering was longer than 10 minutes only for the third sample (PB-11-111). Therefore, Vorlauf time had to be extended from 10 minutes to 12 minutes for that trial. samples had on average somewhat longer time to clear (8 minutes) when compared to AC Metcalfe averages (6 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 slightly shorter than for 2011 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. 11
malts had on average comparable Malt Material Yields to the averages of 2011 AC Metcalfe 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 an average wort colour somewhat higher than the 2011 crop AC Metcalfe 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-11-060) (PB-11-054) (PM-11-076) (PB-11-077) (PM-11-100) (PB-11-111) (PM-12-007) (PB-12-010) Mean CMBTC Metcalfe 2011 Mean Maltotetrose 2.65 3.39 3.56 2.97 3.14 3.05 Maltotriose 13.76 14.03 14.56 14.12 14.12 13.83 Maltose 53.39 56.11 55.26 55.94 55.18 58.13 Glucose 13.46 13.12 12.96 14.20 13.44 13.91 Fructose 2.20 3.26 2.11 2.64 2.55 2.34 Acceptable wort sugar spectrums were recorded for all wort samples (Table 5). samples had on average somewhat lower levels of Maltose and Glucose, and slightly higher levels of Fructose, Maltotetrose and Maltotriose when compared to AC Metcalfe worts. 12
Table 6. Fermentation observations for the brewing trials Parameter (PM-11-060) (PB-11-054) (PM-11-076) (PB-11-077) (PM-11-100) (PB-11-111) (PM-12-007) (PB-12-010) Mean CMBTC Metcalfe 2011 Mean Attenuation Limit (%) 87.6 84.3 85.4 87.3 86.2 85.3 Fermentabilty of all the wort samples were acceptable (Table 6). had on average slightly higher fermentability than the averages of 2011 AC Metcalfe. 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-11-060) (PB-11-054 (PM-11-100) (PB-11-111) (PM-12-007) (PB-12-010) Mean CMBTC Metcalfe 2011 Mean Apparent Ext. (Plato) 1.49 1.87 1.64 1.67 1.74 Real Ext. (Plato) 3.40 3.80 3.59 3.60 3.64 Alcohol (v/v %) 5.24 5.33 5.37 5.31 5.24 Color (ASBC) 3.47 2.98 3.53 3.33 2.67 ph 4.53 4.21 4.26 4.33 4.53 Foam (Nibem) 162 211 187 186 209 Initial Turbidity (FTU) 16.8 40.3 15.6 24.2 13.9 Chill Turbidity (FTU) 24 Hr 18.2 54.7 16.6 29.8 15.2 Three samples were bottled and they produced beers with good quality. Apparent and real extract, as well as final beer alcohol in beers were all comparable to the averages of 2011 AC Metcalfe beers. Average final beer colour for samples was slightly higher than the average AC Metcalfe beer colour readings. AC Metcalfe average had somewhat higher ph readings when compared to products. beer samples had somewhat lower average foam stability than 2011 AC Metcalfe averages, and both values can be considered as good. The initial and chill turbidity for beers indicated acceptable physical and colloidal stability, although AC Metcalfe averages had lower haze readings. In terms of sensory via Expert Taste Panel, the beers received comparable marks to the control AC Metcalfe averages, and were rated as normal good beers with no defects and some good characteristics. The beers had a good appearance, fresh, clear and clean, with slight estery and some diacetyl notes. Results are summarized in Table 8 and Figure 5. 13
Table 8. Expert Sensory Panel analysis for the brewing trials Quality Parameter (PM-11-100) (PB-11-111) (PM-12-007) (PB-12-010) Mean Oxidation 2.4 2.8 2.6 Body 2 1.7 1.85 Flavour 2.1 1.9 2 Palate 2.1 2.5 2.3 Hop Aroma 1 0.9 0.95 Hop Bitterness 1.7 1.7 1.7 Estery 2 2 2 Cereal 2 1.56 1.78 Turbidity 1.2 0.7 0.95 Sour 1.2 1.4 1.3 Sweet 1.9 1 1.45 Sulphury 0.9 0.4 0.65 Overall Quality 2.6 2.7 2.65 Additional Terms Diacetyl 1 1 1 DMS 0.5 1 0.75 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 14
Figure 5. Spider Plot of Expert Sensory Analysis of Two Beers Overall Quality Oxidation 3 2.5 Body Sulphury 2 1.5 Flavour 1 Sweet 0.5 0 Palate PB-11-111 PB-12-010 Sour Hop Aroma Turbidity Hop Bitterness Cereal Estery 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 15