| Beer Diseases | | | | Sterilising with chlorine, iodine or sulfur based sterilizing |
| Look this up on the search engines and you will not | | | | agents will sort out the first. Rapid fermentation and |
| find out very much. Look for beer diseases in | | | | prompt bottling will sort out the other two, so make |
| brewing books and you will find silence (except to | | | | sure that your yeast is good before you start; don't |
| say that you must guard against them). Look for | | | | kill it by adding it to wort that is too warm; don't let |
| beer diseases in published literature and you will | | | | the fermentation hang for lack of warmth. Lastly |
| discover references to Louis Pasteur's work of 1876 | | | | bottle your home brew as soon as its clear. You may |
| which pretty much covered the subject. | | | | want to use isinglass or egg whites to clear the |
| | | | home brew more rapidly. I have had numerous film |
| Film yeast is insidious. Symptoms of film yeast in your | | | | yeast infections mostly due to late bottling. |
| home brew are:- | | | | As lager is slower fermenting you need to take an |
| - A dusty looking scum on top of your beer. | | | | extra precaution: use a closed fermentation bin with |
| - If sampled the affected beer will taste weak and | | | | an airlock. Top fermentation beers can be fermented |
| vaguely unpleasant . | | | | in an open bin, simply covered with a cloth. |
| Film yeast is an aerobic yeast which destroys the | | | | Vinegar infections are much less common. The |
| alcohol by converting it into carbon dioxide and water. | | | | bacterium converts alcohol (its food) to vinegar. The |
| Alcohol is its food. It does not immediately make the | | | | brew is immediately unpleasant and sour to drink. I |
| beer sour, but it quickly makes your home brew | | | | can remember only one vinegar infection in 20 years |
| undrinkable. | | | | of brewing. |
| There are three causes. Firstly the fermentation | | | | Beer is protected to an extent by the hops which |
| bucket was not cleaned properly after a previous | | | | are a preservative, and both diseases attack weaker |
| infection. Secondly the beer was exposed too long to | | | | brews more easily than strong ones. |
| the air, which carries film yeast around. Thirdly the | | | | Incidentally, wine is subject to the same diseases: |
| fermentation was too slow (actually this cause is | | | | though stronger it has no protection from hops and |
| connected to the previous one). | | | | so most wines are dosed with sulfur instead. |
