\begin{tabular}{@{}lclll@{}}
\toprule
                     &                         & &\multicolumn{2}{c}{\textbf{Activity}}\\
                                                                         \cmidrule(ll){4-5}
\textbf{Starter type} & \textbf{Hydration (\%)} & \textbf{Flour type}  & \textbf{Yeast} & \textbf{Bacterial} \\ \midrule
Regular              & 100                     & Strong wheat       & Balanced      & Balanced          \\ 
Liquid               & 500                     & Very strong wheat  & Minimal       & High              \\ 
Stiff                & 50--60                  & All wheat          & High          & Low               \\
\bottomrule
\end{tabular}
