|Fobbing is the foaming of beer during processing or dispense. Depending on when it occurs, fobbing can have
either negative or positive consequences. Fobbing during wort production can contribute to oxidation that will
negatively impact long-term product stability. When used in reference to beer dispense, the term “fobbing”
generally refers to excess foaming while pouring draught beer.
Multiple factors contribute to excessive draft fobbing. These include incorrect line sizing, incorrect line pressure,
uptake of carbon dioxide at the point of origin (i.e., the keg or serving vessel) during or prior to dispense, unclean
beer lines, improperly cleaned and rinsed glassware, incorrect beer temperature at the point of dispense (i.e.,
warm beer), or defects in the beer line.
Fobbing during packaging, particularly bottling, is important in forcing oxygen from the bottle prior to capping. As
the bottle exits the filler, foam rises to the top of the bottle, due to the drop in pressure, displacing the oxygen in
the bottle’s headspace. This is known as “capping on foam.”
Bottling lines will often employ liquid nitrogen or sterile water “jetters” that disrupt the surface of the beer in the
bottle, causing fobbing and ensuring the beer is properly capped on foam. A similar effect can also be achieved by
tapping or “knocking” the bottle on its way to the capper or by use of an ultrasonic burst that causes the beer to
foam as needed.
Another use of the term “fobbing” refers to cask-conditioned beer which has undergone a secondary fermentation
in the cask. Before the beer is ready to serve, the proper level of carbonation must be achieved. When the cask is
first vented, it may be quite active, causing fobbing to occur through the hole in the shive. Some cellarmen will
wipe away the foam and then use the frequency of its reappearance to decide when it is time to reseal the cask.
Ergot is a disease that affects cereal grains used in brewing—most notably rye, but also wheat and barley.
It is caused by the fungus Claviceps purpurea which produces toxic alkaloids in the affected grain that, when
consumed, are poisonous to humans and other animals. Effects of ergot poisoning include convulsions and
seizures, vomiting, gastrointestinal distress, gangrene, hallucinations, and often death.
Ergot poisoning epidemics have been identified as occurring throughout history, especially in Europe in the Middle
Ages, and have been seen in modern times in developing nations suffering from lax oversight of the food supply.
However, improved grain cleaning and milling processes have largely eliminated large-scale ergot contamination
today. The last recorded epidemic-size outbreak of ergot poisoning occurred in Ethiopia in the late 1970s.
Grain crops are most susceptible to infection in years marked by cold springs and damp, rainy summers; the
telltale sign of infection is the presence of dark purplish-black fungal fruiting structures called sclerotia replacing
kernels in the grain head just prior to harvest. Reduced yields and significantly reduced grain quality are hallmarks
of ergot infection, which, along with the development of poisonous alkaloids, can render the crop a total loss.
Rye is the most susceptible cereal grain to ergot infection, although wheat and barley are also affected to an
economically significant extent.
Ergot-resistant varieties of rye, wheat, and barley are not available; however, growing other nonsusceptible
crops for several years in fields known to have ergot sclerotia in the soil can greatly reduce future infections.
Deep plowing can also aid in controlling infection because ergot sclerotia will not germinate when buried under
several inches of soil.
Hope you found this month's column of interest. If you have any questions about beer or brewing
or just want to submit a word for me to discuss here just e-mail it to me.
Thanks and Cheers!
|Fobbing // Ergot
|A new column by
|Jack O'Reilly attended the
famous Siebel Institute/ World
Brewing Academy in Chicago.
|I'm very excited to be part of the BeerNexus team. I think my many years in the
beer business both as a brewer and manger will enable me to explain and
investigate many topics of interest for those who really love craft beer.
Hope you join me every month.
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|Techniques and insights
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