Eda-oke ・ oya-oke

“Branch” vat; “parent” vat

When a batch of moromi is not mashed in a single tank or vat alone, the main tank is called the “parent” (oya-oke), whilst the accompanying smaller tank or tanks are known as “branch” vats (eda-oke). Batches may be divided as moromi can cool too much if mashed in a vessel too large in relation to the quantity of the mash.

Compared to the main tank, eda-oke are much smaller, holding around 1260 litres (7 koku (石) in the traditional reckoning). From their position at the base of the main tank, they are also sometimes called shita-oke (from 下, down or beneath), or ko-oke (from 小, small). They are also sometimes called names such as sanjaku-oke (“three-shaku oke”), sanjaku or sanpachi-oke, all terms referring to their size (one shaku being about 30cm). In recent years, their use has become less common in the course of the trend for simplification in many breweries.