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Equipment · Strainers, moulds and hoops
kuurna · sahti kuurna · wooden mash tub
A Finnish sahti kuurna is a long trough for straining mash into wort. It is distinct from the wooden mash tub; historic wooden forms include a hollowed log.
Finnish farmhouse brewing uses two distinct wooden vessels in the traditional arrangement: a tub for mashing malt and a separate long vessel called a kuurna for lautering, or straining the mash to collect wort. The mash tub holds the grain and hot brewing water while mashing takes place. The kuurna receives the mash afterward; wort drains from it into a separate receiving vessel. Neither is automatically the fermentation vessel.
The kuurna’s job is physical separation. Grain solids remain in the trough while the sweet liquid runs through the filter and out through an opening. This clarifies why the vessel’s bottom arrangement and drainage matter more than a lid or an airtight seal: it is an open draining tool, not a closed fermenter.
A Finnish National Museum record describes a specific kuurna hollowed thin from one piece of wood. Board ends fit into grooves; curved braces, crosspieces and wooden pins with a wedge hold the end structure together. The catalog measures this object at 148 by 51 by 41 centimetres, with maximum dimensions of 152 by 66 centimetres. These measurements belong to that one artifact, not to a standard design or capacity.
In the museum’s recorded brewing method, crosspieces lie across the base to hold a filter bed above the bottom. Rye straw and, for example, juniper branches cover the supports; mash is poured over them and filtered wort drains through a hole at one end into a tub. A juniper bed can contribute its woody, needle-like aroma as well as hold back grain, but its use is not universal. One documented brewer instead used a wire screen in a steel kuurna and preferred the resulting beer without the sharper juniper note.
The long trough is distinctive because it follows the work of farmhouse brewing rather than the shape of modern brewery tanks. Hollowed-log kuurna are documented as a traditional form; a later field report describes a modern steel example preserving that low, elongated outline. The modern example is evidence of adaptation, not a reason to replace the documented wooden vessel in an image of the traditional form.
The wooden mash tub remains separate in the record: its role is to hold the grain-and-water mash before lautering. Sources confirm wooden tubs but do not establish a single size, species or joinery pattern. This page pairs the two tools for their shared brewing sequence without suggesting that they are one object.
Finnish museum records locate a used kuurna at Korvenkylä, Säkylä (Antintalo). A photograph catalogued as sahti-making at Noitala, Hollola, is dated 1900–1909 and shows the long wooden trough in a working scene. These records anchor particular use associations; they do not establish a single birthplace for the kuurna or a date when the design began.
The sources do not give a standard capacity, exact dimensions for the accompanying mash tub, present-day maker, purchase route or care routine. They also do not establish that all brewers use juniper, that all kuurna are made from one tree species, or that a kuurna carries out fermentation. The vessel is best understood through the documented sequence and the individual examples, not by treating one specimen as a universal pattern.
Finnish museum records and a photograph dated 1900–1909 document kuurna in beer and sahti production. The sources do not establish when the vessel was invented or first used.
The kuurna is a mash-straining vessel in the described sequence, not necessarily the vessel in which sahti ferments; documented brewers collect wort separately before fermentation.
Source →The sources document Finnish sahti practice; they do not establish the kuurna's origin or exclusive use in Finland.
The Finnish National Museum record names this use location for one kuurna; it is not a claim that the item was manufactured there.
The source photograph records sahti-making and a kuurna at this named locality; photographer is unknown.
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Finnish National Museum, Seurasaari Open-Air Museum collections, via FinnaForm · Materials · Dimensions · Use · Geography
sahtikuurna; kaukaloThe catalog describes a thinly hollowed one-piece wooden kuurna with fitted board ends, end braces, crossbars, wooden pins and a wedge.
It gives the measurements 148 × 51 × 41 cm, with maximum 152 × 66 cm.
It records use in beer and sahti production at Korvenkylä, Säkylä, and describes a filter bed of crosspieces, rye straw and optional juniper, draining through an end hole into a receiving tub.
Cited in: Two vessels, two stages; A carved trough and its filter bed; Places, dates and what remains unknown
Mika Laitinen, Brewing NordicProcess · Materials · Geography · Variation · History
Sahti and Related Ancient Farmhouse AlesLaitinen describes the traditional farmhouse setup as a wooden mashing tub and a separate tub or trough-like kuurna for lautering.
He documents sahti in Finland and explains that juniper flavor traditionally comes from branches in the filter bed or an infusion.
He says the date when Nordic and Baltic farmhouse-ale traditions took shape is uncertain.
Cited in: Two vessels, two stages; A carved trough and its filter bed; Household craft and changing materials; Places, dates and what remains unknown
Lars Marius Garshol, LarsblogField observation · Variation · Function
Brewing with Olavi the championGarshol documents an Olavi Viheroja sahti brew in 2018 and describes the steel kuurna as retaining the traditional trough shape.
In this brewer's practice, a wire mesh replaces juniper; juniper is not universal.
The kuurna drains mash and wort separately from fermentation; the case documents variation, not a standard material.
Cited in: A carved trough and its filter bed; Household craft and changing materials; Places, dates and what remains unknown
EXARC JournalWooden mash tub · Process
Book Review: Viking Age Brew, by Mika LaitinenThe review describes sahti being mashed in a wooden tub and lautered through a separate wooden trough called a kuurna.
It distinguishes the mashing vessel from the filtration trough and notes that vessel traditions vary with modern equipment.
Cited in: Two vessels, two stages; Household craft and changing materials
Wikimedia Commons; source photograph attributed to Lahti Museums via FinnaHistorical attestation · Form · Geography · Image rights
File:Sahtikuurna.jpgThe file is an extract from a photograph titled as sahti being made at Hollolan Noitalan Hottola in the early 1900s; the record dates it 1900–1909.
The Commons file states CC BY 4.0; uploader Hunsvotti cropped the image from a larger photograph, and the original photographer is unknown.
Cited in: Places, dates and what remains unknown