CHAPTER 15
Brewing Procedure
The following is a step-by-step guide to the classic lager brewing process, using a three-vessel brew house (mash-tun, lauter-tun, combination decoction/wort kettle). The same program can be followed using either a two-vessel (combined mash-/lauter-tun) or four-vessel (separate decoction kettle) brew house.
Mash temperatures given are for 122 degree F (50 degrees C) and 153 to 155 degree F (67 to 68 degrees C) rests; 131 degree F (55 degrees C) and 158 to 160 degree F (70 to 71 degrees C) rests can be substituted. With well-modified modern malts (over 36 percent SNR, and especially over 40 percent SNR), peptidase activity during a 122 degree F (50 degrees C) rest risks depleting the wort of body- and head-forming polypeptides. A brief, combined proteolysis and saccharification rest at 131 degrees F (55 degrees C) better suits malts with an SNR of 37 to 40 percent than a 122 degree F (50 degrees C) rest, and the higher temperatures should be substituted in the decoction program.
For infusion mashing, see appendix B. For step mashing, refer to appendix C.
Malt Examination
Peel the husk away from the dorsal side of twenty or so kernels of malt to expose the acrospire. Chew another dozen or so kernels. Unless the malt is easily chewed and the acrospire has been uniformly grown to from three-fourths to the full length of the kernel, the malt should be step or decoction mashed. This is also true for base malts that are of questionable enzymatic strength, are high in protein, or that are unevenly malted.
Three-Decoction Mash
Expect a three-decoction mash to take from 3 ½ to 9 hours. Begin by crushing the amount of malt called for in the recipe. The malt should be weighed, but it may be measured assuming that one pound equals 4.25 cups, U.S. liquid measure.
Doughing-In
Dough-in the crushed malt by sprinkling it with small amounts of brewing liquor at roughly 58 to 70 degrees F (14 to 21 degrees C) until twenty-four to twenty-eight fluid ounces of liquor per pound of malt has been kneaded in. For a thin mash, when brewing light, quickly fermenting beer, thirty-two to forty fluid ounces of water per pound are required.
Hold for fifteen minutes (or for up to thirty minutes for steely or enzyme-poor malt). Mix regularly and thoroughly to distribute moisture evenly throughout the mash. The malt should be uniformly and universally solubilized. Check for successful moisture penetration of the coarser grits and hard ends of the kernels by pulverizing several between the fingers. Make sure there are no dry pockets or balled flour within the mash.
Acid Rest
For each pound of malt doughed-in, bring twelve to fourteen fluid ounces of liquor to a boil. For a thin mash, sixteen to twenty fluid ounces should be boiled. Knead it into the grain to raise the mash temperature evenly to 105 degrees F (40 degrees C). After twenty minutes, check the mash pH; if it is at or below 5.8 (preferably 5.2 to 5.5), proceed with the first decoction.
Otherwise, acidifying measures must be taken before mashing should proceed. The mash acidity can be reduced by adding acidified mash from a lactic-acid mash. To make such a mash, one or two days before brewing, mash-in 5 percent of the malt to 155 degrees F (68 degrees C). Rest for one hour. Cover and cool, undisturbed, down to 125 degrees F (52 degrees C). Knead in a small amount of dry crushed malt (to introduce Lactobacillus delbrueckii) and cover. No airspace should be left above the mash; cover the mash by pressing food-wrap down over it to seal it from contact with air.
After twenty-four hours at 95 to 120 degrees F (35 to 49 degrees C), the pH will drop below 5. After two days, it will be below 4.5. A lactic-acid mash is most effective when the brewing water is relatively soft. Five percent acidified mash at pH 4.8 can be expected to reduce a mash at pH 6 to below 5.8. At pH 4.5, it will lower the mash pH to about 5.6.
More commonly, the pH of an overly alkaline mash is corrected by employing a portion of sourmalt or cautiously mixing minute amounts of lactic or phosphoric acid into it until the mash pH drops to 5.5. In future brews, adjust the pH of the liquor, rather than the mash, using proportionally similar treatment.
First Decoction
Pull the heaviest one-third part of the mash to the side of the tun and withdraw it to the decoction kettle. The “heaviest” part of the mash means mash with only enough liquid to fill the spaces between the grains, but not so much as to cover them. The decoction should always be thick, with just enough free liquid to prevent scorching. Return any free-standing liquid that settles above the boiler mash back to the main mash. If the mash itself is thin, however, 40 percent or more of the mash volume may need to be pulled for the decoction, and boiling some free-standing liquid with the decoction is inevitable. Use the “Planning Data” worksheet in table 14 to calculate decoction volumes.
Closely cover the cold settlement in the mash-tun and maintain its temperature as nearly as possible at 95 to 105 degrees F (35 to 40 degrees C).
Heat the decoction to 150 to 158 degrees F (66 to 70 degrees C) in ten minutes (or as rapidly as possible), and hold it there for ten minutes to dextrinize it. Heat it to 167 degrees F (75 degrees C) over five minutes, then bring it to a boil in five to ten minutes while lifting the grain up and away from the bottom of the kettle to prevent scorching. Cover and boil it vigorously for five to ten minutes, the longer time being for steely or enzyme-poor malt.
Protein Rest
Return the darkened decoction to the starchy cold settlement by degrees, while lifting and breaking up the mash, over a period of five or so minutes, to evenly raise the temperature of the whole to 122 degrees F (50 degrees C) or within the range of 118 to 128 degrees F (48 to 53 degrees C). Check the temperature throughout the mash, making sure it is even.
Monitor the mash pH; it should drop to pH 5.2 to 5.3. The usual rest period is only five minutes before the heaviest part of the mash is drawn off for the second decoction.
Second Decoction
Withdraw the heaviest 33 to 45 percent of the mash to the decoction kettle (as before, adjust the decoction volume to reflect consistency). Cover both mashes. Heat the decoction to 150 degrees F (66 degrees C) within ten minutes, then through the alpha-amylase range and to 167 degrees F (75 degrees C) over ten to fifteen minutes, and then to boiling, while lifting and stirring. Boil vigorously for five minutes, or for up to twenty minutes for very steely malts, stirring frequently.
Saccharification/Dextrinization Rest
Return the decoction to the rest mash evenly, so as not to scald any portion of the rest mash. Temperature dispersal should be absolutely uniform. The saccharification temperature, usually 153 to 155 degrees F (67 to 68 degrees C), should be reached within five minutes when the beer is to be fully lagered. Returning the decoction gradually, over a period of fifteen to thirty minutes, to a rest temperature of 149 to 151 degrees F (65 to 66 degrees C) favors maltose production when brewing lighter, drier beers.
Hold the saccharification temperature for fifteen minutes; the mash will darken in color.
Test for successful starch conversion. Float tincture of iodine (.02N solution; usual medicine-cabinet variety) drop by drop above a small sample of the mash in a porcelain dish. Check the color at the interface of the iodine and the mash. Continue mashing until there is no color change, or for a sweet, full beer until the reaction is only very faintly mahogany reddish. Disregard discoloration caused by husk particles; it in no way indicates lack of conversion.
Use caution. Iodine is a poison. Do not let it inadvertently taint the mash. Discard all samples and rinse the dish and any equipment that has been contacted by the iodine.
The precise saccharification rest temperature should be maintained. This may be simply accomplished by infusing small amounts of boiling liquor into the mash. Because the mash liquid absorbs a great deal of extract during saccharification, it may become too thick to satisfactorily settle into a well-stratified filter bed. These temperature-maintenance infusions serve to improve filtering of a thick mash and are generally necessary when less than 1 ½ quarts of liquor have been used to mash-in each pound of malt. Thinning a thick mash assures that its density does not interfere with filter bed settlement in the lauter-tun.
Lauter Decoction
When starch end point has been verified, rack off the very thinnest 40 to 50 percent of the mash. Bring it to a boil. Boil vigorously while stirring for five minutes.
Final Rest
Remix the mashes thoroughly, evenly raising the temperature to near 170 degrees F (77 degrees C). Rouse and mix the mash for five minutes while maintaining the lauter rest temperature to force insoluble mash particles into a temporary suspension. This causes a clearly stratified settlement of first the hulls, then endosperm particles, and finally the protein gums to be formed in the lauter-tun.
Single-Decoction Mash
Part 1. Using malt of 33 to 36 percent SNR, mash-in the malt with thirty-six to forty-eight fluid ounces of liquor at 130 to 135 degrees F (55 to 58 degrees C) per pound of malt (the colder the malt is, and the less the volume of liquor being used, the hotter the liquor temperature will need to be).
After five minutes, pull the heaviest 33 to 45 percent of the mash volume and heat it to 150 degrees F (66 degrees C) in ten minutes, to 167 degrees F (75 degrees C) in ten to fifteen minutes, and then to boiling. Boil for five minutes.
Return the decoction to the rest mash for a 153 to 155 degree F (67 to 68 degrees C) saccharification rest. After fifteen minutes, begin testing for starch conversion. Maintain the temperature by infusing with boiling water as necessary. Depending on the fullness desired for the beer, conversion at the conclusion of the rest should give a negative to red-mahogany iodine reaction.
As soon as the desired iodine reaction is achieved, add boiling liquor to bring the dilution up to forty-eight fluid ounces per pound of malt and the mash temperature to near 170 degrees F (77 degrees C), then transfer the goods to the lauter-tun as quickly but as gently as possible.
Part 2. Using malt of 37 to 40 percent SNR, mash-in the malt with thirty-six to forty-eight fluid ounces of liquor at 140 to 145 degrees F (60 to 63 degrees C) per pound of malt for a 131 degree F (55 degrees C) protein/saccharification rest temperature.
After five minutes, pull the heaviest 33 to 45 percent of the mash volume and heat it to 158 degrees F (70 degrees C), rest it for ten minutes, and then heat it to boiling. Boil the decoction for five minutes.
Return the decoction to the rest mash for a 158 to 160 degree F (70 to 71 degrees C) dextrin rest. After fifteen minutes, begin testing for starch conversion. Maintain the temperature by infusing with boiling water as necessary.
As soon as the desired iodine reaction is achieved, add boiling liquor to bring the dilution up to forty-eight fluid ounces per pound of malt and the mash temperature to near 170 degrees F (77 degrees C), then transfer the goods to the lauter-tun as quickly but as gently as possible.
Sparging/Filtering
Fill the lauter-tun to one-half inch above the false bottom with sparge liquor. Give the mash one final stirring and transfer it to the lauter-tun. Maintain the temperature at as close to 170 degrees F (77 degrees C) as possible for ten to fifteen minutes while the filter bed forms undisturbed.
In the meantime, bring the appropriate volume of sparging water to 170 to 175 degrees F (77 to 80 degrees C).
After the malt particles (husks, acrospires, and any starch granules) have settled and the liquid above the protein coagulum has cleared, set the filter bed and flush debris from the space below the false bottom by opening the draincock until a steady trickle of runoff forms. Drain the mash until the protein has settled and the clear liquid above it lies only about one-half inch deep. Smooth and level the mash surface. Maintain the liquid depth above the mash by returning the runoff to the lauter-tun until the wort runs clear. When all the cloudy runoff has been recycled, begin sparging. Open the sparging-water tap, matching the trickle of 170 to 175 degree F (77 to 80 degrees C) liquor to the runoff rate. Carefully balance the inlet and outlet flow-rates so that the liquid level above the mash is not disturbed.
Manipulate the flow, balancing the sparging rate to the runoff, so that the filtering takes 1 ½ hours to complete. Divide the amount of sweet wort to be collected by ninety (minutes) to define the required runoff flow per minute. (Six-row barley with a high husk content may be run off in as little as thirty minutes.) During a slow filtering, carefully rake the lauter mash to within six inches of the false bottom to close vertical channels and improve extract yield. Smooth the mash surface as any cracks appear, and keep the liquid level above the surface of the mash, but not more than two inches deep. Immediately begin heating the wort collecting in the copper to above 170 degrees F (77 degrees C). Sparge until the density of the runoff drops below 3.0 °Plato (SG 1012). Discontinue sparging and allow the mash to drain.
Boiling the Wort
Add a small portion of loosely broken-up boiling hops, to reduce surface tension and the likelihood of boil over, to the sweet wort as soon as all of the extract has been collected.
Check the wort acidity. It should be pH 5.2 to 5.5. If it is below pH 5.0, protein precipitation will be retarded; adjust with a carbonate salt if necessary. Measure and record the density, corrected to 68 degrees F (20 degrees C), or 60 degrees F (15.56 degrees C) if that is the temperature that the hydrometer is calibrated at.
Lauter-tun
Hot Break
Periodically examine samples of the boiling wort to assess protein/polyphenol flocculation. Remove a glassful of wort. The tannin/proteins that mist the wort early in the boil should coagulate into a much smaller number of larger flakes, one-eighth inch long or longer, as the boil progresses. Check the pH. It should drop during the boil to 5.0 to 5.3.
Cold Break
As the end of the boiling period draws near, the flocks in the hot sample should readily precipitate and leave the wort clear. Force-cool the sample; it should slowly cloud again as it cools. This cold break should then settle out from the wort, leaving it clear and bright. If a clean break cannot be established during the designated boil, and the intensity of the boil and wort pH are acceptable, then either the malt or the brew-house program is unacceptable. The finished beer will likely be cloudy and astringent. Do not, however, exceed quoted boiling times, especially when brewing light beers. Longer boiling is not likely to improve clarification unless it is subsequent to a significant correction of the boiling intensity or pH, and will increase the bitterness and discoloration of the wort.
Finishing Hops
Add finishing hops ten to fifteen minutes before the end of the boil, as the heat is shut off, or when the wort is being run from the kettle. The later the addition, the less the bitterness contribution, but the greater the flavor and aroma.
At kettle knock-out, turn off the heat. Check and record the wort acidity. The pH should be 5.0 to 5.3. Measure the wort volume and density, corrected to 68 degrees F (20 degrees C), or 60 degrees F (15.56 degrees C) if that is the temperature that the hydrometer is calibrated at. Correct the volume to the 68 degree F (20 degrees C) reference temperature by multiplying by .96, or by .958 for 60 degrees F (15.56 degrees C). If the density is high, and the volume is less than required, restore it with cold water. Determine extract efficiency using the table below.
| Brew-house Efficiency | |
|---|---|
|
1. Volume of wort, in gallons, at 68°F (20°C): |
1.__________ |
|
2. °Plato of wort, at 68°F: |
2.__________ |
|
3. Multiply line 1 by line 2: |
3.__________ |
|
4. Divide line 3 by table 15, line 1 (anticipated wort volume): |
4.__________ |
|
5. Planned °Plato of wort, from table 14, line 3: |
5.__________ |
|
6. Divide line 4 by line 5: |
6.__________ |
|
7. Multiply line 6 by line 13, table 15: |
7.__________ |
|
Line 7 is the actual brew-house efficiency. Use this efficiency in future brews to more accurately predict original gravity. |
|
Filtering and Cooling the Wort
If the wort will be run through a hop back, lay a bed of fresh hops over the false bottom to form a filter bed. If the wort will either be siphoned from the kettle or run off from a side tap, or if the wort was hopped with pellets, whirlpool the wort with a paddle for two to three minutes so that the hops and trub form a cone at the center of the kettle’s bottom. Allow the hops and trub to settle for ten to fifteen minutes.
Force-cooling the wort quickly (fifteen to forty-five minutes) gives a more complete break than slow or passive attempering, and reduces DMS development. The colder the temperature the wort is chilled to, the better the cold break will be. A wort chiller should always be used. Where an immersible chilling coil is employed, the wort is cooled before it is run off from the kettle. For lager beers, cooling to at least 39 degrees F (4 degrees C) will reduce the chances of chill haze in the finished beer.
Run off the wort, slowly at first, returning it to the kettle without splashing, until the runoff clears. If the wort is being siphoned from the kettle, keep the pick-up close to the side of the kettle and away from the bottom of the kettle until near the end of the run. Run the wort into the fermenter or settling tank.
If the wort is being run into a closed settling tank, allow it to rest undisturbed for several (two to sixteen) hours before racking it off its trub to the fermenter. Expect the wort to precipitate a cold-break sediment equal to 10 to 20 percent of the hot-break trub. If the wort is being run directly to the fermenter, let it splash in freely to aerate it. Keep the cooled wort covered, and work using as sanitary a method and in as clean, dry, and draft-free an environment as possible.
Decant any wort in excess of the amount needed for primary fermentation into sterile containers. Reheat to boiling, cap and refrigerate until needed.
Pitching the Yeast
Most lagers require the pitching of .40 to .66 fluid ounces (8.5 to 14 grams) of thick, pasty yeast per gallon of wort to be pitched, for a rate of 10 to 15 million cells per milliliter. Up to 1 fluid ounce (21 grams) of yeast may be required to ferment a gallon of wort at greater than 15 °Plato (SG 1061).
Shake the starter vessel to mix the yeast sediment into a milky solution. Pitch only the amount of yeast necessary to ensure rapid initial fermentation. Any remainder may be frozen, or covered with fresh wort, then capped with an airlock and refrigerated, for use later in the brewing cycle or for subsequent brewings.
Kraeusening
When kraeusening, “new” beer equal to 10 percent of the primary fermenting volume at up to 5 degrees F (3 degrees C) above pitching temperature is used to introduce active yeast for fermentation. Kraeusening produces strong initial fermentation.
Yeast Starter
A yeast starter is the equivalent of kraeusen beer, but made up from a yeast culture roused into ten times its volume of wort. The ten-to-one dilution is repeated each time strong fermentation becomes evident until the starter is at pitching strength (5 to 10 percent of the volume it will be pitched into). Yeast starters, like kraeusening, promote stronger and faster fermentation starts and blanket the ferment with CO2 much sooner than does pitching yeast sediment.
Yeast starters should be made up one to two days before brewing, from sterile wort and 10 to 20 percent of the pitching volume of yeast. The wort may be from bottled wort saved from a previous brewing, or may be made up in a small brewing to resemble the wort that will be pitched. If the yeast can be aerated, oxygenate it for several hours before pitching to strengthen the culture and reduce the lag phase.
Pitch the yeast as the wort runs into the fermenter. Allow the wort to splash into the fermenter and rouse it splashingly and thoroughly. Fill the fermenter and fit the airlock (blowoff) to it. The temperature at pitching should usually be 42 to 50 degrees F (6 to 10 degrees C). A low initial temperature will produce a beer with less esters and fusel alcohols. To encourage growth, the yeast can be oxygenated by trickling sterile air or oxygen up through the wort for up to an hour after pitching.
Primary Fermentation
Primary fermentation takes five to fourteen days. Temperatures quoted are for full-bodied, dextrin-rich lagers above 10 °Plato (SG 1040) that are to be fully lagered. For maltose-rich wort to be fermented in less time, add 6 to 8 degrees F (3 to 4 degrees C) to the temperature. Do not, however, exceed 60 degrees F (16 degrees C) during primary fermentation and 50 degrees F (10 degrees C) during secondary fermentation if at all possible. Keep the beer out of direct sunlight and avoid drafts and temperature fluctuations.
Check and record the temperature, density, pH, and yeast-cell count of the beer while it is fermenting and lagering only if it can be done conveniently and without any risk of contaminating the beer.
| Primary Fermentation Temperature/Time Guideline | ||
|---|---|---|
|
Temperature |
Duration |
|
|
50–55°F |
(10–13°C) |
5–8 days |
|
48–50°F |
(9–10°C) |
6–10 days |
|
41–48°F |
(5–9°C) |
7–14 days |
Every yeast strain has a temperature optimum, where it ferments well and gives the desired fermentation character. Quoted primary and secondary fermentation temperatures should be adjusted to suit the specific requirements of any particular yeast strain.
Hold the pitched wort, covered and fitted with a fermentation lock, at an ambient temperature of 45 to 50 degrees F (7 to 10 degrees C).
A foam wreath forming at the sides of the fermenter indicates that the lag phase is ending. A light shone on the surface reveals active carbonic gas release.
Low Kraeusen
Six to thirty-six hours after pitching, the foam migrates to the center of the beer surface. The temperature should begin rising. Extract should drop approximately .5 °Plato (SG 1002), and the pH should drop noticeably. The foam cover becomes tightly knit. A light shone on the beer reveals even more CO2 release and a milky turbidity, indicative of the amount of yeast in suspension.
High Kraeusen
Two to four days after pitching, the foam rises up to form looser-knit, cream-colored “rocky heads.” When the temperature of the ferment reaches the maximum recommended for the yeast strain, or 55 degrees F (12 degrees C), attemper the fermenter so that the temperature of the fermenting beer does not rise further. The liquid pressure should fall by .75 to 2 °Plato (SG 1003 to 1008) daily. The pH should drop to about 4.5.
Post Kraeusen
Six to fourteen days (six to ten days is usual) after pitching, the foam head begins to diminish as CO2 production falls off. Extract reduction should slow dramatically, and with a reasonably flocculant yeast strain the cell count will drop below ten million cells per milliliter.
If a diacetyl rest is being employed, force the temperature of the post-kraeusen ferment to rise to 55 to 60 degrees F (13 to 16 degrees C). After two days, lower the ambient temperature again, bringing the beer down to 38 to 40 degrees F (3 to 4 degrees C) at 3 to 5 degrees F (1 to 3 degrees C) per day.
When the extract drop slows to 0.5 °Plato (SG 1002) over twenty-four hours, the head will have completely fallen. Rack the beer into a secondary fermenter/lagering vessel. The beer should be clear and bright. If the yeast does not seem to have largely settled out and still clouds the beer, then the yeast strain is dusty or mutated, the beer may ferment past end point, and it will probably need to be fined.
Make a hydrometer reading of the sample and record it. For beers from worts of 10 to 15 °Plato (SG 1040 to 1060), it should be roughly 30 to 40 percent of what the wort density (OG) was, or 1 to 2 °Plato (SG 1004 to 1008) above the expected final density (FG). Testing with Dextrocheck (reducing-sugar indicator) should show less than 5 percent reducing sugar. Check and record the pH; it should not have dropped much below pH 4.5.
Secondary Fermentation
Clean and sterilize the lagering vessel, preferably rinsing it with sterile, boiled water. Carefully rack the beer in the primary fermenter off of its settlement into the closed lagering vessel. Take care not to carry along any of the sedimented yeast or trub; cease racking when the runoff becomes the least bit cloudy.
Run the beer into the lagering vessel as quickly as possible, absolutely avoiding splashing. Only enough head space to allow for mild foaming should be left above the nearly fermented beer; if necessary restore the volume by topping-up the fermenter with sterile water. Kraeusen beer should be added to produce the smoothest possible beer. Kraeusening generally reduces diacetyl, corrects poor primary-fermentation yeast performance, entrains CO2 in the beer, and gives fuller, mellower flavors.
Seed yeast for starters and culturing should be collected from the primary-fermenter yeast cake.
Fit the fermenter with a fermentation lock. If the hydrometer reading at racking is one-third the density of the original gravity or greater, ferment for seven to twenty-one days, reducing the ambient temperature from 38 to 40 degrees F (3 to 4 degrees C) down to 33 to 37 degrees F (1 to 3 degrees C) when carbon dioxide production falls off. If the reading is much less than one-third of the original hydrometer reading, the beer lacks slowly fermenting dextrins and should nearly ferment out in seven to ten days before the temperature is reduced for lagering.
Beer that will not be lagered is usually held in a secondary fermenter for only one to two weeks, and is fermented down to the terminal extract value before being chilled to clarify and sediment it in preparation for packaging.
Lagering
Lager tradition calls for seven to twelve days secondary fermentation and lagering per each 2 °Plato (SG 1008) of the original wort hydrometer reading, with the beer temperature falling to as close to 33 to 36 degrees F (1 to 2 degrees C) as possible. The above notwithstanding, if the hydrometer reading at racking was much less than one-third the value of the wort reading (OG), the beer should not be secondary fermented/lagered for more than one week for each 2 °Plato of the wort reading; four or five days per each °Plato is usual. Lowering the temperature to 30 to 33 degrees F (-1 to 1 degree C) immediately after secondary fermentation reduces lagering times.
Beer that will be bottle-conditioned is lagered at atmospheric pressure. Lagering may be carried out under pressure, but only if the lagering vessel is able to be safely pressurized, is fitted with a pressure-relief valve, and the beer will not be bottle-conditioned. Do not attempt to lager under pressure in a glass carboy. Use only a Cornelius keg or the like fitted with a pressure-relief valve. The vessel should be closed when the beer is .2 to .5 °Plato (SG 1001 to 1002) above the anticipated terminal gravity.
Fermentation is complete when the hydrometer reading is at or near the terminal extract value and no drop or visible activity has been experienced in the last five days. A reducing-sugar analysis should show less than 2 percent, indicating that the beer has fermented out.
If the beer is to be fined, prepare the finings. For fining with gelatin, measure out one gram (one-eighth teaspoon) of 95 percent pure gelatin and two fluid ounces (sixty milliliters) of cold water or beer per gallon of beer to be fined. Cover the solution and let the gelatin hydrate for one hour.
Gently heat the solution to 150 to 160 degrees F (65 to 70 degrees C) to dissolve the gelatin; do not let it come to a boil. Do not let it cool below 120 degrees F (50 degrees C) before thoroughly mixing the hot solution into the aged beer as a stream, by stirring, or by rocking the lager vessel for two to three minutes, without aerating the beer. Allow the beer to rest undisturbed for seven to fourteen days at below 50 degrees F (10 degrees C) before racking for bottling.
Prepare isinglass finings by measuring out one-half gram of the finings and four fluid ounces (120 milliliters) of sterile beer or water for each gallon of beer to be fined (for batches of more than one barrel, use five grams of isinglass in .15 gallons, per barrel of beer). Check the pH; reduce the acidity to pH 2.5 to 3.0 with phosphoric acid if necessary. Closely cover the finings while they undergo acid hydrolysis at 55 to 65 degrees F (12 to 18 degrees C) for twenty-four to thirty-six hours. Mix thoroughly into the aged beer.
Isinglass will clear the beer within twenty-four to seventy-two hours. The beer temperature should be held stable or be let rise slightly until it is racked.
Dry hops or hop extract can added either anytime before the finings or with them, but they are not usually added afterward.
Bottling
The ruh beer is usually quietly racked off of its sediment to a third vessel for mixing with the priming solution, whether that be priming sugars, wort, or kraeusen beer. Refer to table 23 for guidelines for the amounts of each to add for a desired level of bottle carbonation.
| Bottle Priming | |||||||
|---|---|---|---|---|---|---|---|
|
For Bottle Pressure* At: |
Approximate: Oz. Dextrose/Gal. |
Fl. Oz. Kraeusen/Wort/Gal |
|||||
|
50°F |
32°F |
40°F |
60°F |
10°P |
12°P |
14°P |
|
|
atmospheres |
|||||||
|
2 |
1.2 |
1.5 |
2.5 |
1.2 |
13.5 |
11 |
9.5 |
|
2.5 |
1.5 |
1.9 |
3.2 |
1.5 |
17 |
14 |
12 |
|
3 |
1.9 |
2.35 |
3.8 |
1.8 |
20.5 |
17 |
14.5 |
|
3.5 |
2.3 |
2.8 |
4.4 |
2.1 |
24 |
20 |
17 |
|
* At sea level. For elevations other than sea level, reduce bottle priming by approximately 3.3% for each 1,000' of elevation. 50°F is the standard temperature at which bottle pressure is gauged. |
|||||||
Bottling should take place in a clean, dry area that is free from drafts. Mix the carefully measured priming solution into the ruh beer without splashing, rousing it for several minutes to ensure uniform dispersal and to induce carbon dioxide to release from and blanket the beer.
Inspect the bottles. Reject any with chipped rims or residue deposits. Wash in warm water, using cleansing solution only if necessary. Thoroughly brush the inside surfaces. Sterilize bottles in a dishwasher on the sanitizer cycle, with live steam by stacking wet bottles in an oven and heating them to 200 degrees F (93 degrees C), in a .2 percent chlorine bath, or in a water bath at above 170 degrees F (77 degrees C). Invert the bottles on clean paper towels to drain.
Carefully dispense the primed beer into the sanitized bottles, filling them at least to within three-fourths of an inch of the rim. Loosely cover the bottles for several minutes to allow carbon-dioxide release to drive off oxygen in the head space before securing the caps and inverting the bottles to disclose leakage.
Hold at 50 to 65 degrees F (10 to 18 degrees C) for fourteen to twenty-one days before beginning to reduce the temperature to 32 to 45 degrees F (0 to 7 degrees C) for conditioning and storage. Do not subject the bottled beer to drafts or temperature fluctuations.
Draft Beer
Clean the keg in the same way you would clean bottles; if the keg is wooden, check its pitch or paraffin surfacing for cracks or deterioration, and melt out the old wax and reline as necessary. Usually beer for draft is drawn into the keg with just less than 1 percent fermentable extract left in it to provide carbonation for cask conditioning. Otherwise, add kraeusen beer or priming solution in sufficient quantity to produce 1.5 atmospheres (20 psi) pressure at 50 degrees F (10 degrees C). Fill the keg to within two inches of the bung hole and rouse thoroughly at priming to induce a mad condition. After several minutes, drive in the bung with a rubber or wooden mallet. Condition for ten to fourteen days at 50 to 65 degrees F (10 to 18 degrees C) before tapping.
A CO2 source may be used to carbonate the beer. At its simplest, this may be accomplished by applying CO2 pressure to the keg, with the regulator set for the pressure (psi) called for in the “Volumes of CO2” table found in appendix D, and shaking the keg several times over a fifteen-minute period, until the flow of CO2 upon shaking falls off.
Troubleshooting
Mash
Balled starch in mash: Poorly handled doughing-in of the crushed malt; malt too finely crushed.
Mash pH too high: Brewing water overly alkaline; liquor for pale beer not acidified, poor quality malt. Correct by adding acid or mineral salt.
Mash pH too low: Brewing water overly acidic; lactic-acid- or acetic-acid-bacteria-spoiled malt. Correct pH with alkaline mineral salts.
Mash doesn’t saccharify: Lack of diastatic enzymes in mash, either destroyed at malting or by mash temperatures above 160 degrees F (71 degrees C); inappropriate pH. Add crushed diasatic malt and continue mashing; check pH. As a last resort, add diastatic enzyme preparation.
Set mash: Poorly converted mash; malt poorly doughed-in; malt too finely crushed; mash poorly stirred up before filtering; too fast a runoff rate. In most cases, correct by thoroughly stirring up the mash and allowing it to resettle; cut the mash to within six inches of the bottom to reopen channels of extract flow in the mash. Press hot water up from under the false bottom. Reduce runoff/sparging rate.
Wort
Low extract: Not enough malt used; poor sparging efficiency; insufficient crushing; balled starch from poorly handled doughing-in; wrong mash pH; insufficient mash enzyme activity. Check for unconverted starch by making an iodine test of a wort sample. Continue brewing the same volume at the lower density.
Poor kettle break: Flocks do not sediment; excessive protein decomposition during malting or mashing; wort agitation insufficient; temperature too low; improper pH; too few hop tannins in the boil; poor quality malt. Increase heat and wort movement. Check pH and hop rate; correct if necessary. If the wort clears but throws very little sediment, then malting or mashing protein digestion may have been overdone.
Poor cold break: Wort cooled too slowly; improper pH; wort lacks tannins; excessive protein digestion. Cool to below 32 degrees F (0 degrees C) to encourage sedimentation.
Wort tastes sour: Wort pH too low; coliform, acetic, or lactic-acid bacteria contamination. Check pH; heat wort to above 140 degrees F (60 degrees C) and re-cool; pitch quickly. Sourness may diminish with aging or be masked by adding burnt malt, finishing hops, or calcium carbonate.
Sour or vinegar taste/smell: Acetic acid bacteria. As above.
Fermentation
Insufficient lag phase: Wort insufficiently aerated; too much trub carried into ferment; temperature too high. Ferment has strong solvent and fruity aroma. Irreversible.
Excessive lag phase: Too little yeast pitched; yeast weak, degenerated, poisoned, or shocked by temperature change; wort extract too low; inappropriate pH; wort too cold; inadequate oxygenation of wort. Rouse in new yeast. Correct temperature to suit yeast strain.
Sluggish fermentation: Weak or inappropriate yeast strain; yeast degenerated, poisoned, or shocked by temperature change; fermentation temperature too cold; iron, chlorine, or nitrates in the water supply; low wort extract; wort lacking in readily fermentable sugars or soluble nitrogen. Establish correct temperature and pH; repitch.
Spotty low-kraeusen head, unable to support trub: Weak yeast; temperature too low; wort inadequately hopped; deteriorated hops. Raise fermentation temperature; rouse in new yeast.
Fermentation ceases before high kraeusen: Temperature too cold; extract too low or from wort lacking readily fermentable sugars or yeast nutrients. Yeast strain mutated by exposure to too much glucose (catabolic repression) or lack of oxygen (petite mutants). Establish correct temperature; repitch.
Yeast break, head falls prematurely: Temperature lowered prematurely; mutated yeast strain cannot ferment maltotriose; too fast a pH drop in the ferment (bacterial contamination); inadequate extract. Establish correct temperature, pH; repitch.
Poor yeast flocculation; yeast do not settle; porous sediment: Dusty yeast strain; wild yeast contamination; inappropriate pH; temperature too high. Reduce temperatures. Fine the aged beer.
Haze in beer after high kraeusen: Insufficient protein reduction during mashing; inadequate boil; wild yeast contamination; dusty yeast pitched. Reduce temperature before racking and during lagering; fine; as last resort treat with papain or similar proteolytic-enzyme extract.
Yeast floats to surface after high kraeusen: Fermentation contaminated by wild yeast; culture yeast degenerated; brewing water too soft; sudden temperature rise; pH too high. Skim. Degenerated yeast have an unpleasant smell; when yeast performance is poor or abnormal, sample the bouquet.
Bottled or Kegged Beer
Roughness: Abnormal water composition; insufficient boil; excess tannin; excessive/alkaline sparging; insufficient kettle evaporation; hot-side oxygenation.
Fruity aroma/flavor: From esters, higher alcohols, acetates of higher alcohols. The consequence of underoxygenation of the pitching yeast, too high a fermentation temperature, too low a pitching rate, or a deteriorated yeast strain. When unpleasant and combined with vegetal aroma and flavor, from coliform contamination of the wort or yeast culture.
Celery odor: H. protea contamination, probably from tainted yeast culture. Irreversible.
Bitter-vegetable taste: From deteriorated hops (oxidized beta-acids).
Buttery (diacetyl) flavor: Where strong and like rancid butter, from lactic-acid bacteria, significantly Pediococcus. Slight or pleasant diacetyl flavor more often from low pitching rate, underoxygenation, petite mutants in culture yeast, or characteristic of the yeast strain; beer racked off its primary sediment too early or oxidized in the secondary.
Cardboardy taste: Oxidation; from too much air in bottle headspace; trub carried into/lipids oxidized in the ferment; warm storage, mishandling; insufficient boil; when with poor head retention, from lipids in the beer.
Sulfury aroma/flavor: Too low a fermentation temperature; poor rinsing of sulfur-based sterilant; from wild yeast, Zymomonas or coliform bacteria. May be characteristic of yeast strain, or from autolization of sedimented yeast. Except when from bacterial contamination, may be reduced by aging or by scrubbing with carbon dioxide. Corny aroma and flavor is characteristic of dimethyl sulphide (DMS), from poorly malted barley, especially six-row; high-moisture malt; hot wort not chilled quickly enough; coliform bacteria contamination.
Sour taste: From too low a pH; from acetic- or lactic-acid bacterial contamination.
Medicinal aroma/flavor: From wild yeast or bacteria; chlorine in the ferment; plastic contamination; excess of phenolic material from oversparging or weak wort boil. Accentuated by high fermentation temperatures.
Astringency: Excessive sparging, hot-side aeration, yeast autolization, excessive or oxidized trub.
Skunky odor: Beer light-struck. Avoid direct sunlight during brewing and in package; reduce headspace.
Rotten egg odor: Hydrogen sulphide; yeast-strain characteristic; fermentation by wild yeast; weak fermentation; in bottled or kegged beer, may be from contamination by Zymomonas bacteria.
Disagreeable smell/taste; turbidity, acidity: Pediococcus or Bacillus contamination of the primary ferment. Irreversible.
Green apple flavor: Acetaldehyde, the principle volatile acid in beer. From too high a fermentation temperature; yeast-strain characteristic; bacterial contamination.
Banana aroma/flavor: Acetates. Yeast-strain characteristic; wild-yeast contamination; too high a fermentation temperature.
Thinness: Wort extract too low; excessive mash protein digestion; dextrin-poor extract.
Haze: Poor mash protein digestion; insufficient boil; wild yeast; bacteria; oxidation of beer; poor starch conversion in mash.
Gelatinous precipitate: Excessive sparging; poorly degraded hemicellulose.
Lack of head: Excessive protein rest; overmodified malt; too high an adjunct ratio; lipids in ferment (excessive sparging; autolized yeast); overfoaming in fermentation; overboiling; insufficient or deteriorated hops; contact with oil.
Gushing: Excess of priming sugars; beer not fermented out before packaging; temperature fluctuation; mishandling; old malt; iron; wild-yeast contamination.
Problems encountered with bottled beer can be accentuated by holding a sample at 85 degrees F (30 degrees C) and visually monitoring it for several days, then evaluating the forcing sample. Precipitates or surface formations generally indicate microbial contamination. Culturing or flavor evaluation may pinpoint organism responsible.