I found this:
Crude rapeseed and sunflower oils were heated to 80 °C and water solution of citric acid (30 %) was then added in amount of 2 % (by volume of the oil). The mixture was stirred for 20 minutes. The oil/acid mixture was kept at 80 °C up to 15 min, cooled down to 25 °C, mixed with water (1 %) and transferred to a holding vessel. After settling for 60 min the mixture was centrifuged for 20 min to separate acid degummed oil from its by-products."
I assume Buchner filtering instead of centrifuging is adequate, and the acidic water solution is removed with a separatory funnel.