The major cold shock protein of E. coli, CspA, has been an excellent model for studying ß-sheet properties because it is a monomeric protein composed only of ß-sheets. When temperatures cool, bacterial cells produce this protective protein to bind to nucleic acids for fundamental life support. Six aromatic amino acid residues, including a tryptophan, are partially solvent exposed and used for binding to nucleic acids. The following analysis of the stability and folding of CspA has been performed to understand the functional effects of replacing aromatic residues with aliphatic ones at specific locations. Cassette mutagenesis was used to replace aromatic residues 18 and 31 with leucine, a hydrophobic residue. The mutant protein was then purified via affinity chromatography. Electrophoresis and a circular dichroism (CD) spectroscopy were then used to verify purity of the protein. Concentration was determined by the optical density at 350 nm. Wild type CspA and mutant's stability and folding properties were examined by urea denaturation and ssRNA binding through fluorescence spectrometry. Using the CD, thermal stability of the protein was determined. These results detail the effects of replacing aromatics with hydrophobic residues in the folding and stability of CspA.