Hi Sedona-are you from that awesome beautiful place. I love it there! I have made Colby without problem on several occasions but not using the recipe here on the forum. A couple of observations though- I usually add cacl at the rate of ~ 1/4 tsp per gallon. Adding 1 tsp /gal as you have indicated may well be the problem because at that high a rate of application it will actually inhibit coagulation. Another question I would have is the addition of nacl with the rennet. I have not done mine at that point, I always add mine at the time of milling. All additives be it rennet, cacl,lipase, or coloring should be diluted in 1/4 cup of cool sterile water prior to adding. Some like the lipase need to stand 20-30 minutes prior to being added. I have not read through the colby recipe here on the forum, maybe there are other members here that have used it that can add some comments. Don't get down on yourself. Making cheese is part art, part science-all done with a home chemistry kit!