It looks like I have resolved this question. After Albert Brunnert/Brummer died, his wife remarried, and had a son that died at young age. The burial notice of the son lists the second husband as 'Neslage genant Brummer'. This means that she had the inheritance of the Brummer farm, leading to her new husband taking the Brummer name, with the young son, who had just died.
This information tells us that Albert owned the Brummer farm, and had inherited it from his parents. This means that his parents must have been Arendt Korman and Petronella Brummer, the previous owners of the farm. It also makes it likely that Albert was their oldest son.