Transcript
Diagnosis of fermentation problems Problem Fermentation has not started at 2 days since yeast was added.
Diagnosis 1. Lag time. 2. Fermentation may be occurring without evident signs (eg bubbles)
Cause Solution/ Prevention. 1. Natural period where the yeast 1. Reduce lag time by using a good strain of builds its cell count in initial yeast, ensure it is not pitched at a low stages of fermentation. temperature. Rehydrate the yeast in 2. Incomplete seals on fermentation tepid water prior to use to reduce lag vessel or natural lack of kraeusen. time. Take liquid yeast out of the fridge to room temperature before usage. Give the yeast time to catch. This is not a problem but part of the natural process which can be helped or reduced. 2. Check seals on fermentation vessel; use a hydrometer to see if the sugar concentration has dropped from its OG. If it has then it is fermenting. This is not a problem so long as the sanitary environment of the fermentation vessel is not compromised by a leak or crack. 3. Bear in mind different conditions provide varying patterns in the natural process of fermentation. Exercise patience. 4. Try making up a yeast starter in future to increase the number of yeast cells prior to pitching, simply sterilise a jar and introduce the yeast to a small measure of dissolved malt extract a few days in advance, continue adding sugar over time until you are ready to pitch the yeast. 5. Ensure the wort is sufficiently aerated before pitching your yeast, yeast requires oxygen for the initial stages of fermentation.
Fermentation has not started and it has been over 3 days.
1. Fermentation may be occurring without evident signs (eg bubbles) 2. Bad Yeast. Yeast may not have worked or may be damaged and really struggling. 3. Wort got too cold 4. Wort was too hot
1. Incomplete seals on fermentation vessel or natural lack of kraeusen. 2. If the yeast came with an old kit it may have gone out of date. Some yeast sachets are not fully viable. 3. Yeast goes into hibernation when it is too cold, check the fermentation temperature. 4. Yeast damaged by being pitched into wort before cooled to beneath 30 degrees Celsius.
1. Use a hydrometer to see if the sugar concentration has dropped from its OG. If it has then it is fermenting. 2. Purchase new yeast; ensure it is for the right style. Have spares just in case. 3. Ensure wort is between 17-29 Degrees Celsius before pitching yeast.
Beer appeared to be fermenting but then stopped before schedule.
1. Stuck Fermentation 2. Completed Fermentation
1. Too cold- If temperature dropped overnight the yeast may have gone into hibernation. 2. Inappropriate choice or preparation of yeast for beer. 3. Environment became too warmLikely to have completed the fermentation extremely quickly. Not likely to have killed the yeast 4. Yeast was particularly strong and completed fermentation quickly
1. Stir the beer and get put in a warmer room. Ensure the beer sits in condition between 16-26 degrees Celsius. 2. Ensure the appropriate choice and preparation of yeast. For high gravity beers pitch more than a sachet or make a yeast starter. Aerate the wort appropriately. Rehydrate yeast prior to use. 3. Quick fermentation or fermentation at high temperatures can produce esters and off flavours so check by looking and sniffing, leave in secondary fermentation for a short period before bottling. Check everything with the hydrometer for the most accurate information on the progress of the fermentation. Bear in mind different conditions provide varying patterns in the natural process of
fermentation. Exercise patience. Wort darker than expected
Scorching of extract or beer on element. Wort more concentrated than anticipated.
Heavy extract poured into water and not fully homogenising, hitting and burning on the element.
Bring water to boil and stir thoroughly before adding extract.
Incomplete seals on fermentation vessel.
Check for cracks, or that the lid is firmly fitted. This is not a problem so long as the beer is not exposed. Check for signs of fermentation, if there are none, new yeast may need to be added. 1. If brewing all grain use Irish moss for the last 15 minutes of the boil. 2. Always try to keep the sparging water temperature hot but just below 80 degrees Celsius. 1. Include wheat or Carapils in your all grain recipe to improve head retention. Remember the balance of adjuncts as well. 2. A dirty glass could be the key, rinse in very hot water and see if any improvement is made. 3. If the beer is under-carbonated, add a little more sugar when bottling. 1. Some sources say such infections can be skimmed off the top but chances are the batch will need to be poured away. 2. Chance storage conditions; ensure the beer is fermenting in preferably in dry shaded conditions. 3. Thoroughly sanitise all equipment after an infection so the problem does not
The airlock doesn’t appear to be bubbling.
Loose seals. Stuck fermentation.
Haze when refrigerated
Chill Haze
1. If All grain brewing then the boil was not sufficient enough, either too short or not vigorous enough. 2. Sparge water was too hot
Poor Head retention, foam.
1. Not enough Proteins in brew. 2. Dirty glassware 3. Flat beer
1. Good head retention is created by proteins in the brew. Not enough protein in the brew may be a result of using too many adjuncts such as oats. 2. If the beer is flat it is undercarbonated.
Mold, floating green or white spots, hairs.
Mold, Bacterial infection.
1. Poor storage or fermentation environment. Musty or damp areas are more likely to lead to such infections. 2. Poor sanitisation regime.
resurge. Final Gravity (FG) seems too high
1. Stuck fermentation 2. Low attenuating yeast or extract 3. Mashing too highly
Original Gravity (OG) seems too low when measured on the hydrometer.
1. Kit not thoroughly dissolved or homogenised 2. Poor sparging efficiency
Beer is Hazy.
Protein Haze Hop haze Yeast Haze
1. Too cold- If temperature dropped overnight the yeast may have gone into hibernation. Inappropriate choice or preparation of yeast for beer. Environment became too warmLikely to have completed the fermentation extremely quickly. Not likely to have killed the yeast. Yeast was particularly strong and completed fermentation quickly. 2. Yeast has fermented as much as it can or wort is high in unfermentable sugars as a result of an extract rich in dextrin sugar or a higher mash temperature. 1. Beer kit and extract syrups require thorough stirring in hot water to fully homogenise with the water added to reach the OG. 2. Inefficient sparging using water which is not hot enough or sparging too quickly. 1. Protein haze caused by an ineffective boil in extract or all grain brewing, leaving polyphenols. Removed largely during the hot and cold breaks during brewing. Or sparging at too high heat above 80 degrees
1. Use a hydrometer to see if the sugar concentration has dropped from its OG. If it has then it is fermenting. Purchase new yeast; ensure it is for the right style. Have spares just in case. Ensure wort is between 17-29 Degrees Celsius before pitching yeast. 2. Not too much of a problem for some beer styles like strong bodied ales. Only a problem is the sweetness or body is intrusive, add highly attenuating yeast. If this fails, use a different type of extract when brewing the next batch or mash at a lower temperature.
1. Use a couple of kettles of boiled water and vigorous stirring to fully homogenise the kit before topping up with cold water. 2. Sparge with water just under 80 degrees Celsius, drain slowly while adding sparge water slowly when fly sparging. Do not add too much water. Improve sparging technique. 1. For protein hazes, adjuncts in the boil such as Irish moss and protofloc copper finings can assist the protein break. Ensure there is a healthy looking hot and cold break if brewing all grain or extract. Bear in mind that clarity of beer is now becoming less sought after and
2. High levels of alpha acids from hops can cause a degree of haziness. 3. Yeast hazes are caused unsettled yeast in the bottle. Overabundance of yeast in the bottle. Yeast not fully flocculated or settled. Yeast disturbed in the fermentation vessel during siphoning.
Beer appears thick like engine oil.
Lactic or Pediococcis Infection
Poor sanitisation or exposure of beer. Yeast/ Bacterial strains used in some Belgian beers. Beer goes sick for several months, appearing viscous. Causes ropiness where thick strands appear.
Thick foam has formed on top of the beer.
Natural result of fermentation. (Kraeusen)
Thick foam (kraeusen) has not formed on top of the
Natural lack of kraeusen. Failed fermentation.
The kraeusen is a consequence of yeast rehydrating. The co2 the yeast produces carries yeast to the surface forming this layer. It can be somewhat protective, stopping microbes from falling directly into the beer. The kraeusen is a consequence of yeast re-hydrating. Sometimes the kraeusen
cloudiness is now largely considered to assist the flavour in many beers. However it can be a result of a problem in your brewing technique 2. For yeast hazes- Leave bottle to rest in the fridge before drinking. Pour carefully and steadily. Have patience after the fermentation if the beer looks cloudy, wait for the yeast to sediment out then siphon carefully. Alternatively add finings to speed up the flocculation. Siphon carefully between fermentation vessels and into bottles. Suspend the end of the siphon, preferably attached to a u-bend, above the yeast bed (trub) to lessen yeast transfer. Develop clean siphoning technique. Add finings to the fermentation vessel, Kwik clear or isinglass force flocculation. Improve sanitising regime. Check seals on fermentation vessel and reduce air contact or exposure time. Thoroughly sterilise kit after pouring infected batch away. This infection can lodge itself into plastic, if the infection reoccurs, new equipment may be needed. This is not a problem but provides a reason for racking your beer after primary fermentation to a secondary fermentation vessel, to ensure reduced yeast while bottling.
Check surface of beer for any sign of small bubbles. Shine a torch through the fermentation
beer.
naturally doesn’t form, but the beer will still be fermenting, so it is not a problem.
The thick foam is coming through the airlock and causing a mess. The Airlock is clogged.
Blowout.
A peculiar surface has formed on the surface in secondary fermentation. It is definitely not a krausen.
Infection. Oily residue
The tap on the fermenter is leaking
Too tight or loose. Perished seals.
Thin whitish growth on surface of wine, growing over time.
Flowers of wine (Fleur)
1. Vigorous fermentation. 2. Fermentation vessel too small.
Poor sanitisation or exposure of beer. Infections take many forms. Closer identification of the infection may be yielded by smell. Hop oils or residue can form a slight film. This is of no concern. If the tap has been tightened too much the rubber washer can be put out of place.
Infection by wild yeast.
vessel to reveal if bubbles are forming within the beer. Check the beer is fermenting using a hydrometer. If it is not fermenting then it may be that the fermentation never began or has become stuck. 1. Fit a blow off pipe, tubing instead of an airlock which runs into a jug of water. Some beer is lost in this process. 2. If using a 25 litre fermentation vessel for a 23 litre batch of beer, think about purchasing a larger vessel. Improve sanitising regime. Check seals on fermentation vessel and reduce air contact or exposure time. Thoroughly sterilise equipment after pouring infected batch away. If the problem persists you may need to buy new fermentation bins. We recommend that you only attach a tap to a bottling vessel, having a tap on a primary fermentation vessel causes more problems than it solves in our experience. Check the washers and o-rings for wear. Check tightness of tap. Seals can be completed by the application of petroleum jelly.
