Ayran is a yoghurt drink produced in Turkey. Ayran is manufactured traditionally by adding water and salt into yoghurt or industrially by fermentation of diluted milk with water and further dilution with salt containing water after fermentation. Optimum consistency and no serum separation are desired characteristics for ayran. Use of stabilizers in traditionally manufactured ayran to prevent serum separation during storage was studied. High methoxyl pectin, guar gum, locust bean gum and gelatine at different concentrations were added to traditionally manufactured ayran and the samples were evaluated for rheological and sensory properties and serum separation during storage for 15 days at 4 degreesC. Guar gum provided the highest apparent viscosity and consistency index and prevented serum separation in ayran. However, guar gum provided an oily mouthfeel that was not suitable for ayran. High methoxyl pectin and gelatine did not prevent serum separation in ayran at a level of 0.25% but were effective at an increased concentration of 0.50%. Both high methoxyl pectin and gelatine affected the taste and the odor of ayran and the ayrans containing these stabilizers were found unacceptable in the sensory analysis. Locust bean gum at a level of 0.10% prevented serum separation and increased apparent viscosity without affecting the taste and the odor in ayran. (C) 2003 Elsevier Ltd. All rights reserved.