Production of cold filtered beers requires a higher microbiological than pasteurized beers. Microbiological process control has as major disadvantage: the time gap between sampling and offering the results. A process orientated decision is not possible. New control strategies and analysis methods offer possibilities in increasing microbiological product quality. Microbiological results are statistical results. The higher the number of samples the higher is the probability that this result is "right". The major limitations in correctness of the results are the quality of sampling, the number of microorganisms in a sample, "quenching" effects due to overloads with known bacteria or yeasts, the grow limitations of the used broth, the "viability" of sampled germs. Classical microbiological methods detect only "viable" microorganisms which will grow during analysis time, for example slow growing yeasts won't be detected at all. Production of low level (zero) contaminated beer (zero-fault production) has to follow a different control strategy. The first major difference to routine production is the aim to produce beer without any microorganisms in it. There is no difference between live or dead microorganisms. All cleaning and disinfectant steps are optimized to a certain reduction of germs. The aim of a cleaning step has to be a complete removal of any microorganisms. If there are changes in contamination rate the possibility increases that live microorganisms might come into the next production step. Cleaning procedures have to be optimized to remove all organic dirt during caustic cleaning. The following rinse step has to be done in a way that no microorganisms will have the chance to be transferred into the acid - cleaning step. Even no dead germs are allowed to be transferred. This is one of the major requirements for zero contaminated beer production. The cleaning process can be as sure as possible due to the optimized process. Cold filtered beer without any heat treatment prior to or after filling has to have no microorganisms in it. Optimizing process steps - for example during filtration - offers the opportunity to reach this aim without any risks. Beside the requirement of stable and sure processes a fast estimation of the microbiological beer quality has to be made. The second major difference is sited in the detection speed of germs. Classical methods with analysis times of more than 3 days are not able to help to optimize cleaning processes. Novel fluorescence based detection methods overcome this time limitations. It is possible to detect live and dead bacteria and live and dead yeast cells in filtrable samples within <30 minutes after sampling.