A recent addition to the Sheffield brewing scene, the brewery of Saint Mars of the Desert (SMOD) is perhaps unique as we believe it is the only Yorkshire brewery to possess a coolship. Based at 90 Stevenson Road, Attercliffe, SMOD commenced brewing in late 2018. The equipment was mostly supplied by Sheffield-based Moeschle (UK) Ltd.
Coolships (koelschips in Flemish) are vessels which are relatively shallow and have a large surface area: imagine a large, shallow bath. They allow the wort to cool quickly and enable spontaneous fermentation with lactobacilli, which provide sourness. It also becomes the home for Brettanomyces and other wild yeasts, which together add earthy notes. After a few hours, possibly overnight, the wort is moved to a fermentation vessel and, over time, brewer’s yeast (Saccharomyces cerevisiae) finishes the fermentation. The initial process can only happen during the cooler months of the year as this reduces unwanted moulds.
In Belgium, this method is used to produce lambic. The wort is often run into oak tuns, where it may remain for periods of up to three years. Lambics are then blended to produce gueuze (often called “oude gueuze”, which means it is unsweetened). Fruit may also be steeped in lambic. Boon Oude Kriek (6%) is a prime example: drinking Boon Kriek (4%) alongside Delirium Red (8%) recently was like comparing a complex fine wine to alcoholic fruit juice.
Since 2013, Elgood’s Brewery in Cambridgeshire have used a set of two (formerly redundant) open copper cooling trays situated at the top of their tower brewery in order to initiate spontaneous fermentation. This is followed by a long period in stainless steel tanks to produce ‘cambic’: Blonde Lambic Style Sour Ale (6%), Coolship Fruit and Coolship Mango (both 5%). Elgood’s won the ‘best sour beer lambic in Europe’ class at the 2015 World Beer Awards with their Coolship Fruit receiving a gold medal at the 2017 International Brewing Awards.
Also, in the UK, Burning Sky in Sussex installed a coolship in 2017 while The London Beer Company are building the UK’s first mobile coolship. Samuel Smith brew organic fruit beer at Melbourn Bros’ All Saints Brewery in Stamford, Lincolnshire. Here, a coolship is used to allow the wort to cool rapidly before yeast is added. Across the Atlantic, several breweries use coolships. For example, Allagash (Portland, Maine) produce a Cerise (6.7%).
We look forward to seeing the SMOD coolship in use and sampling ‘Attercliffe Sour’ as it joins Barnsley Brie and Henderson’s Relish as a niche South Yorkshire product.