A foeder (pronounced FOOD-er) is the Dutch word for a large wooden barrel set on end used for either long term fermentation or primary fermentation and innoculations. In French it is spelled foudre, and sometimes spelled foedre by some American breweries (ref needed). A foeder can range in size from home brewer to commercial scale.
"As for the Foeders, you'll want to get the Foeder in place and swollen right away. Hot Liquor from your HLT will do the job. I really like to set up a CIP type loop. About 1 bbl of HLT liquor in the foeder then a loop with a spray ball up top in the foeder through the manway hole. Then we use a product called ACTO 140 sold by Berko chems [Birko Chemicals]. We loop that for about 30-60min. Then rinse with HLT liquor. Then if you can't purge with CO2 and fill with beer the next day we fill the Foeders up with potassium metabisulphite and citric acid. The rate is 2g of Kmeta and 1g of citric acid per litre of filtered water. Then keep this in the Foeder till you are ready to empty and fill with beer." - Chad Yakobson in an email to Brad Primozic; independently verified and approved for publication by Chad Yakobson in a private email with Dan Pixley .
- James Howat of Black Project Spontaneous Ales describes his process of rinsing and steaming a new 'Stella' foeder that is 11hL (~9.4bbl / 290gal), and made of Slovenian Oak.
- Tips and advice on reviving a 100 year old foeder.
- Swelling a foeder in one day with garden mister heads, by Mat Waddel and Jace Marti.
Egg shaped foeders sit horizontally and are reminscient of an egg shape. This has the benefit of taking advantage of vertical space, as well as limiting headspace moreso than traditional foeders .
The following businesses specialize in the crafting and/or selling of foeders.
- Foeder Crafters
- Premier Wine Cask.
- Rocky Mountain Barrel Company (May not be reflected on website; offers barrels converted to foeders)
- Wilhelm Eder 
- Keystone Fermentation Supply.
- Discussion on upright versus horizontal foeders.
- Discussion on picking up oak character/tannins from young and old foeders.
- Thread with tips on building foeders.
Additional Articles on MTF Wiki
- Conversation with Brad Primozic on the Milk The Funk Facebook group. 3/5/2015.
- Conversation with Mike Makris of The Rare Barrel and Brandon Jones of Yazoo Brewing Co regarding rinsing and flushing foeders. 12/22/2015.
- Shane Stewart and Ryan Buxton. Milk the Funk Facebook gropu post on egg shaped foeders. 02/16/2018.
- Conversation with Jeff Porn on MTF. 5/25/2015.