Seaweed (Eucheuma spinosum) is a potential export commodity to be developed. Besides the high market demand, Indonesia has large resources enough to either natural and cultured. Eucheuma spinosum seaweed can be processed into carrageenan which has a high economic value. Carrageenan is a hydrocolloid compound which is a long chain polysaccharide compounds extracted from seaweed species karaginofit. Carrageenan is widely used in food industry, medicine, cosmetics, textiles, paint, toothpaste and other industries. Carrageenan has a very important role as a stabilizer (stabilizer), thickener (thickening), gel formers, emulsifiers.

The purpose of this study was to determine whether there is interaction between immersion medium and method of separation of physico-chemical properties of carrageenan, to determine the effect of immersion media, and to determine the effect of different separation methods of physico-chemical properties of carrageenan.

This research use randomized block design (RAK) is arranged with 2 factors and each repeated 3 times. The first factor is the type of immersion medium (fresh water immersion, immersion with Na-bisulfite) and the second factor is the method of separation (90% isopropanol with lime, isopropanol 90% without lime, freezing 24 hours with lime, coagulation 24 hours without lime).

The results showed that there is interaction between the media type of immersion and separation methods of physico-chemical properties of carrageenan, such as gel strength, water content, brightness, sulphate content, viscosity, residue CaCO3. The best treatment is obtained from fresh-water immersion treatment 90% isopropanol with lime (N0E1), with a yield of 9.86%, 8.79% CaCO3 residue, the brightness of 73.20, 16.09% sulphate content, ash content 19.79 %, water content 6.63%, viscosity 58.3 CPAs, and the gel strength of 20.51 mm / g / sec.