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FTEC 422 Lab Report 1
- 1. FTEC 422 Lab Report 1 Name: John Schnettler Style of Brew: Kölsch Brew Date: 2/11/15 Kegging Date: 3/4/15 Sensory Evaluation Date: 3/11/15 Batch Volume: Target: 40.0 l Original Gravity: Target= 12.140° P (Actual= 11.3° P) Final Gravity: Target= 2.912° P (Actual= 2.02° P) Material Bill Water Additives: Ingredient Amount Step Time Calcium Chloride 18.40 g Mash 60 minutes Lactic Acid 13.10 ml Mash 60 minutes Grist Bill: Malt Amount Color (European Brewing Convention) Breiss Brewers Malt (2 Row) US 7.00 kg 4.0 EBC Munich Malt 10L 0.83 kg 19.7 EBC White Wheat Malt 0.68 kg 4.7 EBC Boil Ingredients: Ingredient Amount Time Merkur (13.60% alpha-‐ acid): Hop addition 11.0 g 60 minutes Sterling 2013 (6.70% alpha-‐ acid): Hop addition 57.0 g 15 minutes Whirlfloc: Clarification 1 Tablet 10 minutes Sterling 2013 (6.70% alpha-‐ acid): Hop addition 39.0 g 5 minutes Yeast: German Ale/Kölsch (White Labs #WLP029)
- 2. Water Treatment Starting Water: Fort Collins Water analysis: 1. Hardness = 100 ppm 2. Alkalinity = 80 ppm 3. pH = 6.9 4. Ca = 17.3 ppm 5. Mg = 1.6 ppm 6. Cl = 2.9 ppm Criteria: Produce a light to medium light bodied, clean, crisp, clear, mildly sweet and low ester straw to gold ale with low hop character. We decided as a class to increase the hardness of the beer to 2:1 hardness to alkalinity ratio as well as lower the mash pH of the water to increase wort fermentability by providing the optimum saccharification temperature. Therefore, we aimed for a water profile with a calcium content of 80 ppm with a mash pH of 5.4. Determination: In order to produce the desired water profile, we decided as a class to utilize calcium chloride and lactic acid to treat 80.0 l of water (approximately 1/3 mash tun water and 2/3 hot liquor tank water). Calcium ions are important in stabilizing mash alpha amylase enzymes, reducing mash pH by reacting with phosphates to create insoluble compounds releasing H+ ions, aiding the formation of hot break by enhancing protein coagulation, and increasing clarity. Chloride ions are known to balance the flavor profile of beer and also influence sweetness. Therefore, we calculated that we would use 18.40g of calcium chloride in order to contribute these benefits of each ion as well as to increase permanent hardness and remove alkaline water’s buffering capacity. We avoided the use of magnesium due to the fact that although it shares many impacts on beer as calcium, it is much less effective and as a result is required in greater amounts. We also chose to add permanent hardness in the form of chlorides rather than sulfates in order to contribute a subtle sweetness rather than enhance hop bitterness, which is not characteristic of the Kölsch style. Using 18.40g calcium chloride brought us to our desired hardness to alkalinity ratio and 80-‐ppm calcium concentration; however, we needed to further reduce the mash pH and therefore turned to lactic acid. Our classmate Trent calculated 13.10 ml of lactic acid would effectively bring our mash pH down to 5.4. Malt Analysis Malt Extract Methods for DBFG and DBCG: First we tested for the specific gravity (using ASBC Method of Analysis) of our Breiss Brewer’s Malt dry basis fine and coarse grinds
- 3. using a laboratory conducted mash. By testing for the malt’s extract potentials, we determined the Brewer’s Malt DBCG to have a specific gravity of 6.8° P and the Brewer’s Malt DBFG to have a specific gravity of 7.8° P. Although DGCG is a more realistic representation of the actual grist used in brewing due to the need of a certain extent of coarseness to preserve the husk and promote filtration, DBFG is useful in determining the grain’s ultimate affinity for saccharification. This is why the DBFG specific gravity is higher than the DBCG. Malt Moisture Content: By placing roughly 10 grams of Brewer’s Fine into the Brainweight moisture content analyzer we were able to calculate a moisture content of roughly 3.4%, indicating we had a well malted barley with low moisture content. Having malt with low moisture content is essential due to the fact that it greatly reduces the likelihood of microbial spoilage or flavor/aroma loss over time. Malt Sieve Analysis: (Brewer’s Malt DBCG Grist= 115g) Sieve Amount Percentage #10 64 grams 56.19% #14 26.7 grams 23.44% #18 9.4 grams 8.25% #30 5.8 grams 5.09% #60 4.4 grams 3.86% #100 1.2 grams 1.05% Pan 2.4 grams 2.11% This sieve analysis indicated that our Brewer’s Malt DBCG Grist was too coarse based on the percentages of retained kernels on the #10 and #14 sieves which, combined were higher than our target retention of 55%. Therefore, we adjusted our mill 0.38 to 0.34 in order to slightly decrease the coarseness of the grain for the proper ratio of extractability vs. husk friability lending to its ability to act as a filtration bed following saccharification. Expected SRM of Finished Beer: °L = EBC / 1.97 Briess Brewer’s Malt= 4.0 EBC/1.97 = 2.03 °L Munich Malt= 19.7 EBC/1.97 = 10 °L White Wheat Malt= 4.7 EBC/1.97 = 2.39° L SRM = (Malt Color °L x Malt Weight lbs) / Total Kettle Volume Gallons Briess Brewer’s Malt= (2.03° L x 15.43lbs)/12 gallons = 2.61 SRM Munich Malt= (10°L x 1.83 lbs)/12 gallons = 1.53 SRM White Wheat Malt= (2.39° L x 1.38 lbs)/12 gallons = 0.27 SRM Total SRM = 4.41 SRM
- 4. Malt Bill Characteristics: • Briess Brewer’s Malt (2-‐Row) was chosen as our base malt (82.2% of total grist bill). Aside from lending consistency and malty flavors, the grain had high potential for extract (>81%) based on its kernel plumpness and starch content, acceptable protein content (11.63%), high diastatic power (154° Lintner), and decent friability. Therefore, this malt will be an effective base malt based on its high contribution of fermentable sugars based on high starch and low protein content as well as will act as an effective filtration bed based on its low total and soluble protein contents. • Munich Malt 10°L was chosen to add further malty fullness and a golden, orange color to the beer. The malt has high melanoidin levels as a result of Malliard reactions, which will contribute to its color and flavor enhancement. The malt makes up a small portion of our grist (9.8%) and has a low diastatic power (40° Lintner) that is still capable of saccharification. Ultimately, the grain may contribute fermentable sugar but its primary purpose is color and flavor enhancement. • White Wheat Malt was chosen to add slightly bready malty flavors as well as to improve head retention based on its higher protein content. The malt makes up a small portion of our grist (8%) and has a high diastatic power (160° Lintner). This malt will contribute little color based on its low SRM. Hypothesis -‐ Based on our water treatment with calcium chloride and lactic acid, we expect a final product with a 2:1 alkalinity ratio and a slight amount of body and sweetness that successfully saccharified. Furthermore, based on our aforementioned malt analyses and selections, we can expect a sessionable final product that is light to medium-‐light bodied, straw to light golden colored, with bready malty flavors. We also expect a beer with low hop character, low ester profile, and absence of chill haze. Brew Method (Brew Date: 2/11/15) Mashing: 1. After adding approximately 6.13g calcium chloride and 4.37ml of lactic acid to our mash kettle containing 25 liters of water (and approximately 12.27g calcium chloride and 8.73ml of lactic acid to the hot liquor tank containing 55 liters of water), we mashed in at 3:07pm. 2. Our strike water was added to our 8.51kg of grist at 73° C producing a mash temperature of 62.5°C (at 3:12pm) which was quite a bit lower than our target mash temperature of 66.7°C. Therefore we re-‐circulated (rather than incorrectly heating the mash tun with the burner as someone suggested) the heat and eventually achieved a mash temperature of 66.6°C (at 3:36pm). 3. During recirculation, the mash pH was determined to be 5.8 at 3:25pm, higher than our expected pH of 5.4. 4. After thirty minutes of mash resting, an iodine test was performed yielding a negative result at 3:37pm and began vorlauf. This indicated saccharification had successfully occurred.
- 5. Observations/Conclusions: -‐ The initial mash temperature was too long which has a negative impact on the enzymes’ ability to effectively convert starch to fermentable sugars. Inadequate enzyme activity will lead to inability to saccharify or lower fermentability and resulting lower attenuation and higher levels of residual sugar. However, we were able to increase the temperature of our mash and verified that saccharification occurred through the use of an iodine test. In the future, wind and cooler conditions (since we brew outside Gifford) should be considered based on their ability to lower mash pH and action should be taken to prevent this from happening. -‐ Our mash temperature of 66.6°C incorporated a balance of both alpha amylase and beta amylase enzymes. Alpha amylase favors higher temperatures and a more full-‐bodied beer and beta amylase favors lower temperatures and a lighter bodied, drier beer. Since a majority of the mash rest was spent at lower temperatures before being brought to this balanced temperature, the final product should be more light-‐bodied. -‐ Our higher than expected mash pH of 5.8 indicated that we probably needed to add more lactic acid to further acidify our mash. While the enzymes still seemed to function properly at this pH given the successful thirty minute saccharification, it must be later considered that this may adversely affect our final product based on inadequate enzyme activity. Lautering/Sparging: 1. We began separating our wort from our grain bed at 3:51pm. 2. We sparged with 36.0l at 78.3°C until we completed lautering at 4:30 pm. Observations/Conclusions: -‐ Sparging should ideally function as a slow rinsing of the grains with warm water to gather any residual sugar not separated by the original draining of mash rest water. However, we mistakenly added the sparge water too quickly which could potentially lead to lower extraction of residual sugars. This was a big mistake to be learned from and not made again. This event necessitated the need to keep an eye out for a lower starting gravity than expected. -‐ Our change in mill settings previously mentioned didn’t seem to negatively impact the effectiveness of the grain husks acting as a filtration bed, there were no problems with the actual separation of wort from grain bed process. Boil: 1. At 4:33pm we reached a boil with a pre-‐boil pH of 5.6 and gravity of 9.7° P. As the boil commenced, we added 11.0 grams of Merkur hops as our primary bittering hop addition. 2. Forty-‐five minutes later, at 5:18pm, we performed our second hop addition of 57.0 grams of Sterling hops contributing both bitterness and aroma. 3. At 5:23pm, we added Whirlfloc as our kettle coagulant. 4. At 5:33pm, another 39.0 grams of Sterling hops were added as our primary aroma hop addition. In addition, we began our whirlpool at this time as well as ended our boil. At the end of boil we had 45 liters of boiled wort and a pH of 5.59. The whirlpool was ended at 5:43pm.
- 6. Observations/Conclusions: -‐ As previously mentioned, we were not trying to produce a beer with a prominent hop character based on the parameters of the Kölsch style. However, we still utilized Merkur hops, whose high alpha acid content (13.6%) and low co-‐humulone content contributed mild bitterness via isomerization to balance the light-‐bodied beer. In addition, we also utilized Sterling hops, which lend herbal, spicy, and slightly floral and citrusy aromas when added at the end of boil. Not only were we attempting to correctly match the Kölsch style, but this minimal hop character beer also allowed for greater focus on water treatment and grain analysis and selection, the major topics of this brew in particular. -‐ Whirlfloc (an Irish moss/carrageenan blend) was added to the boil in order to assist the formation of hot break (in addition to the whirlpool) by precipitating haze-‐causing proteins and beta-‐glucans. This is especially desirable in a Kölsch where clarity is an important parameter of the style. Knockout/Yeast Pitch: 1. At 5:45pm we began knockout into a keg at 14°C using oxygen at psi. 2. The initial gravity of our wort prior to fermentation was measured to be 11.3° P. We decided to pitch three packages of German Ale Kölsch Yeast (WLP029) due to the fact that each vial of yeast contains roughly 150 billion cells and the following calculation, 1.5 million cells (lager yeast) x 45.4 l x 11.3° P = 769,869,000,000 cells, indicates three packages is close enough (450 billion cells). Observations/Conclusions: -‐ The knockout occurred quickly reducing the risk of aldehyde and/or dimethyl sulfide formation in the wort. -‐ Our initial gravity of 11.3° P (at 45.4 l) was lower than our expected gravity of 12.140° P (at 40.0 l) due to the fact that our actual total volume was also higher and therefore the wort and its fermentable sugars weren’t as condensed as expected. In addition, our accidental rapid sparging also may have contributed to this lower than expected initial gravity. -‐ This Kölsch Ale Yeast was ideal for our beer due to its clean, low-‐ester profile, which matched our quality parameters for what we were trying to brew. The yeast strain is also fittingly attenuable and lends to the fermentation into a light-‐bodied beer. Fermentation/Conditioning/Packaging: Date: Gravity: Temperature Step 2/11/15 11.3°P 14°C Pitch 2/13/15 5.9°P 24°C Fermentation 2/16/15 2.22°P 20°C Fermentation 2/18/15 2.02°P -‐-‐-‐ Cold Crash 2/27/15 2.02°P -‐-‐-‐ Racked 3/4/15 2.02°P -‐-‐-‐ Kegged
- 7. Observations/Conclusions: -‐Fermentation proceeded rather quickly, which came as a bit of a surprise based on the yeast quantity pitched. Although we thought three packages of yeast containing a total of 450 billion cells (which it seemingly was), this came up fairly short of our calculated yeast quantity of nearly 770 billion cells meaning we under pitched. This could’ve led to a slow or even uncompleted fermentation and could’ve also stressed the yeast leading to a number of off flavors such as fusel alcohols and undesirable sulfurous flavors. Again, although it seemed fermentation was facilitated with ease by our yeast (based on time and our actual final gravity that was lower than our theoretical final gravity) at this point we still out to be mindful of potential off flavors that may have been produced during this fermentation. -‐ The fermentation temperature fluctuated quite a bit likely due to our inability to temperature control the brew lab during winter where the heat was being turned on and off. Ideally we wanted to ferment just below ale temperatures (roughly 14-‐17°C), but we ended up as high as 24°C. While this shouldn’t kill off the yeast, the warmer fermentation may lend some esters to our beer to be considered when sampling our final product. -‐ We kegged this beer into two 1/6 barrels to make packaging quicker and less labor intensive. We carbonated it in the cooler for 6 days at 16 psi until the day before sensory evaluation in which we increased the pressure to 25 psi. Sensory Analysis (Date: 3/11/15) Visual: • The beer was light yellow as a result of the light (low SRM) malts we utilized. • The beer was slightly opaque indicating slight chill haze and inadequate reduction of proteins or beta-‐glucans. • The beer had only slight head retention, which comes as a bit of surprise based on our use of high alpha-‐acid hops and residual protein in the beer. Perhaps this occurred based on our somewhat low protein malt bill (white wheat malt was used sparingly) or the low carbonation of the beer. • The beer also had decent lacing that could’ve been affected by a number of factors such as hop and protein content or the cleanness of the glass being sampled from. Aroma: • The beer had slight fruit esters likely due to fermentation at warmer temperatures. In addition, we noted a pear, apple like aroma, which is indicative of acetaldehyde. Normally, the presence of acetaldehyde indicates an incomplete fermentation, but this seems unlikely due to the high attenuation of our beer and resulting lower final gravity than expected. Perhaps these aromas were more attributed to ester production during fermentation. • The beer had slight aromas of honey, which can be directly attributed to our use of Munich malt. There were also some bready aromas that were also either attributable to our malt selection or even yeast.
- 8. • The beer had some slightly floral (geraniol) and grassy hop aromas, which can be directly attributed to our use of Sterling aroma hop additions. Flavor: • The beer had a light caramelly maltiness, which can be attributed to our use of Munich malt. • The beer also had slight hop bitterness resulting from our hop additions, especially the addition of Merkur. • The beer had a slight fruity sweetness, which can most likely be attributed to ester production during fermentation. Perhaps some of the perception of sweetness came from our use of calcium chloride. Mouthfeel: • The beer was medium-‐light bodied based on our malt selection, attenuative fermentation, and mash temperature choice balancing alpha and beta amylase enzymes. Despite a slight chill haze, there was low overall viscosity due to low protein content of our beer. • The beer was smooth, coating, clean, and balanced based on our water treatment with calcium chloride. • The beer had low carbonation thus lacking a biting bitterness, which ultimately led to a palatable beer with greater focus on flavor. Overall: • The beer met BJCP guidelines to a tee in terms of appearance, aroma, flavor, and mouthfeel. We successfully brewed a clean, sessionable Kölsch that was medium-‐ light bodied, had low esters, low hop flavor, and slight hop bitterness. Conclusion -‐ Based on our water treatment, malt analyses, malt selection, and other brewing parameters aforementioned, we ultimately came pretty close to completely verifying our expectations and hypothesis. We produced a medium-‐light bodied beer based on our use of calcium chloride, our malt selection, and mash regimen. The beer also was light golden in color and had bready and honey malty aromas and flavors, all of which can be directly attributed to our malt selection. In addition, the beer had a slight sweetness as a result of our manipulation of body and use of calcium chloride. The final product slightly strayed from the hypothesis based on the fact that esters were present likely as a result of warmer fermentation temperatures. In addition, the beer had a slight chill haze based on haze-‐ forming proteins and beta-‐glucans, which wasn’t expected or desired based on Kölsch style guidelines. Overall, our water treatment and malt selection as well as other, less emphasized brewing parameters, contributed to an ale both consistent with our hypothesis and expectations as well as the BJCP guidelines. The brewing of this beer ultimately proved successful despite some issues (higher mash temperature, too quick of sparge, non-‐ temperature controlled fermentation) based on the fact we produced a drinkable, sessionable Kölsch ale.