Advice & Hygiene
The importance of sterilisation is key. There is more spoilage as a result of poor attention to hygiene than anything else. Then we wonder what is the point of all of the effort, let alone the disappointment arising from throwing away 40 pints or 30 bottles of wine.
Fermenting beverages attract a number of moulds, bacteria & fungi. If allowed, bacteria will settle in crevices & confined areas of equipment, especially if left damp in dark areas & go on to affect production adversely producing unpleasant odours & tastes. This can be easily controlled by either scalding everything that comes into contact with the ferment with boiling water or by the use of sulphites or chlorine based sterilants & then subsequently rinsing.
During fermentation it is important to keep air at bay to prevent oxidisation, through the use of airlocks or large surfaced containers allowing the CO2 to blanket the brew. Adequate levels of alcohol & CO2 act as a bacteride, so low alcohol brews need to be carefully protected.
During maturation vessels need to be airtight unless air is sought for the contribution of a particular taste such as in port & sherry. So unless you are well practised in the art of brewing & fermenting play it safe & sterilise all equipment & ingredients where recommended, always keep musts & worts covered, sulphite wines after racking & at the minimum your efforts will be clean & palatable.