Murphy & Son Limited – FAQs - Fermentation Problems

Murphy & Son Limited
Alpine Street
Old Basford
Nottingham, NG6 0HQ

Tel: 0115 978 5494
Fax: 0115 924 4654
email: info@murphyandson.co.uk

Fermentation Problems

The exact cause of fermentation problems is not always readily identifiable.

As a general rule, the following actions may help to overcome the problem:
Pitch more yeast
Rouse, or increase the amount of rousing
Add a well balanced Yeast Food, eg Murphy Yeast Aid
Increase the temperature of the fermentation

Investigations can then be made as to the specific cause of the original problem, allowing actions to be taken to prevent recurrence.

Nature of the Problem: Fermentation is slow, or slow to start
	Possible Cause	Possible Remedy
FAULTS IN PROCESS	Insufficient aeration	Rouse or increase the vigour of rousing.
	Premature attemperation	Pitch more yeast. Agitate. Run hot liquor through the attemperator.
	Ambient temperature too low	Run hot liquor through the attemperator. Increase ambient temperature if possible (Heating, insulation, draught exclusion).
FAULTS IN THE WORT	Temperature of wort too low at pitching	Pitch more yeast, adjust pitching temperature in future brews.
	Oxygen content low	Rouse. Measure and adjust oxygen content/aeration in future brews.
	Zinc Content too low	Add Zinc or a Yeast Food containing Zinc (eg Murphy Yeast Aid).
	Free Amino Nitrogen (FAN) content too low	Measure FAN. Adjust mashing conditions and/or malt nitrogen specification. Check Grist compostion.
	Wort clarity - the presence of too much or too little particulate matter	Check copper breaks and adjust rate of copper finings. Check wort separation system.
	pH & buffering capacity incorrect	Check wort pH. Adjust liquor treatment. Check mashing conditions. Check soluble nitrogen. Check Grist compostion.
FAULTS WITH YEAST	Low viability	Pitch more yeast. Check yeast viability. Improve yeast handling & storage procedures. Replace culture if necessary.
	Excessive presence of contaminating organisms (bacteria, wild yeast, amorphour matter)	Acid wash the yeast. Replace with fresh culture.
	Pitching rate too low	Pitch more yeast. Increase pitching rate.
	Imbalance of strains when using mixed strains	Readjust proportions by skimming earlier or later. Top up one strain. Replace with fresh culture.

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Nature of the Problem: Sticking, or failing to reach attenuation target
	Possible Cause	Possible Remedy
FAULTS IN PROCESS	Skimming too early	Adjust
FAULTS IN PROCESS	Insufficient yeast in suspension	Increase time and/or extent of rousing.
FAULTS IN THE WORT	Wort fermentability	Check attenuation limit. Adjust mashing conditions and/or malt specification. Check quantity and type of copper sugars.
FAULTS WITH YEAST	Strain deterioration	Replace culture.

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Nature of the Problem: Premature sedimentation/Head formation of yeast
	Possible Cause	Possible Remedy
FAULTS IN PROCESS	Over attemperation	Adjust rate of cooling.
FAULTS IN THE WORT	Presence of focculation inducers eg Proteins or divalent metal ions	Rouse to re-suspend the yeast. Adjust composition of mashing liquor. Check mashing procedure and/or malt specification.
FAULTS WITH YEAST	Adsorption of material on to cell surface	Rouse to re-suspend the yeast. Wash pitching yeast or replace culture.
FAULTS WITH YEAST	Deterioration of yeast leading to increased flocculence	Rouse to re-suspend the yeast. Replace the culture.

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Nature of the Problem: Failure of sedimentation/Head formation
	Possible Cause	Possible Remedy
FAULTS IN PROCESS	Use of slack malts	Check malt specification.
FAULTS IN PROCESS	Incorrect rousing	Adjust rousing procedure.
FAULTS IN THE WORT	Lack of flocculation inducers (Protein, divalent metal ions, suspended solids)	Cool to sediment yeast or dress fermentation with kieselguhr or pumice. Adjust composition of mashing liquor. Check mashing conditions and/or malt specifications.
	Presence of flocculation antagonists, eg sodium or potassium ions	Adjust composition of mashing liquor.
	Wort clarity - presence of too much or too little particulate matter	Check copper breaks. Adjust copper finings rates. Check wort separation system.
	Low level of hop substances	Check bitterness level and increase hop rate if necessary.
FAULTS WITH YEAST	Strain deterioration leading to loss of flocculation	Cool to sediment yeast or dress fermentation with kieselguhr or pumice. Replace culture. Check yeast handling and storage procedures.

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Nature of the Problem: Overattenuation
	Possible Cause	Possible Remedy
FAULTS IN PROCESS	Inefficient skimming	Adjust skimming procedure.
FAULTS IN PROCESS	Attemperation too late	Attemperate earlier.
FAULTS IN THE WORT	Wort fermentability too high	Adjust mashing temperature and quantity and type of copper sugars.
FAULTS WITH YEAST	Failure of yeast to separate	Cool to sediment yeast or dress fermentation with kieselguhr or pumice. Replace culture. Adjust composition of mashing liquor. Check yeast handling and storage procedures.

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