Following an apprenticeship as a pastry cook, Wiltrud Baier (born in 1967) enrolled at the Filmakademie Baden-Württemberg. There she met Sigrun Köhler, with whom she founded the production company "Böller und Brot" after graduating in 2000. While mainly focussing on documentaries, they also make shorts, video installations and thumb cinema. Most of their works follow a certain theme, for instance "Time", "Money" or "Faith".

The short "How Time Flies – Wie Zeit fliegt" (2000) portrays Sigrun Köhler's grandfather at the age of 100 years and won awards at several international festivals. An extended, feature-length cut of the film won the Documentary Award at the Sehsüchte Festival in Berlin/Potsdam.

"Schotter wie Heu" (2002), a documentary about a bank in rural Germany which still operates without computers, got rave reviews and also did well at the box-office. Also set in the countryside, their next film "Der große Navigator" (2007) follows a Swabian missionary who is ordered to East-Germany after working 22 years in Papua New Guinea. Their made-for-TV documentary "Alarm am Hauptbahnhof" chronicles the public protests against the multi-billion railway project "Stuttgart 21" and received the 2012 Grimme Award.

The following year saw the release of "Where's the Beer and when do we get paid?", a documentary on Jimmy Carl Black, legendary drummer of Frank Zappa's band, who lived in rural Bavaria in the years before his death.

Baier and Köhler presented their next film at the Zurich Film Festival in October 2015: "Wer hat Angst vor Sibylle Berg?" ("Who's Afraid of Sibylle Berg?"), a portrait of the titular writer and playwright. The following year, the two began work on "Narren," a documentary about the preparations for and the people behind the famous Rottweiler Fasnacht carnival parade. The premiere took place in the fall of 2019 at the Hof Film Festival. Due to the Corona pandemic, the film's theatrical release had to be postponed several times until November 2021.