Lauter tuns typically have slotted bottoms to assist in the filtration process. The term derives from the taxation paid on "tuns" or casks of wine. Cooled liquor flows down to the first floor and the fermenting tuns. Three Tuns was licensed in 1642, 56 years earlier than Shepherd Neame. Among their cargoes were over 80,000 tuns of wine. Ketton Ox, Lord Nelson, Red Lion, Three Tuns, Tom Brown, and Union. The town has two micro-breweries, including the Three Tuns, the UK's oldest brewery. There is one public house, the Three Tuns. That vessel returned to London in April 1801 with 450 tuns of sea elephant oil. Local legend is that they stayed at The Three Tuns in Long Street. It is blended from "Old 5X", which is aged for two years in oak tuns. Both the imperial and US tuns were subdivided into smaller units as follows. No ship more than 20 tuns was permitted to leave port. Standard tuns of wine came to serve as a measure of a ship's weight capacity.