The shipment for considerable distances of cream to be made into butter, either from receiving stations or from individual farmers, is a common practice in many sections. Much of this cream is sent without refrigeration and undergoes extensive changes as a result of the activity of the organisms contained. 'l'he type of fermentation that occurs is influenced to a considerable extent by the types of organisms present, but other factors, the most important of which is apparently the temperature, cause a significant effect. One of the important fermentations occurring in cream during the warm months is the "yeasty" or' "foamy" fermentation.
Hammer, B. W. and Cordes, W. A.
"A study of lactose-fermenting yeasts present in "yeasty" cream,"
Research Bulletin (Iowa Agriculture and Home Economics Experiment Station): Vol. 5
, Article 1.
Available at: https://lib.dr.iastate.edu/researchbulletin/vol5/iss61/1