This work investigates the capability of Fourier-Transform near infrared (FT-NIR) spectroscopy to monitor
and assess process parameters in beer fermentation at different operative conditions. For this purpose,
the fermentation of wort with two different yeast strains and at different temperatures was monitored
for nine days by FT-NIR. To correlate the collected spectra with Brix, pH and biomass, different multivariate
data methodologies were applied. Principal component analysis (PCA), partial least squares (PLS) and
locally weighted regression (LWR) were used to assess the relationship between FT-NIR spectra and the
abovementioned process parameters that define the beer fermentation. The accuracy and robustness of
the obtained results clearly show the suitability of FT-NIR spectroscopy, combined with multivariate data
analysis, to be used as a quality control tool in the beer fermentation process. FT-NIR spectroscopy, when
combined with LWR, demonstrates to be a perfectly suitable quantitative method to be implemented in
the production of beer.