Usually when the mashing process is over and the liquid is transferred to the fermenter there's a head-space of air. Lately I've made smaller batches of approximately 5 liters (a huge inefficiency, i know) but my bucket has 20 liters of volume. So, does this enormous head-space places a greater chance of contamination? If so, how sensitive is this process (like does the amount of air increases exponentially the chances of contamination)? Tks!