First and most important is to learn how to keep good note's of the entire process. Start by noting the product preparation prior to smoke/cooking. Then record the type, species and amount of wood. You also want to record type of smoke generator used, internal, external, etc. Record the color, density and length of time that smoke is applied along with the finished results such as color and taste. You may then learn to smoke to a desired color rather than time.
You will find that smoking times will vary depending on the color and density of your smoke. The advantage of using the mailbox type generator is that it produces what I refer to as a much cleaner or smoother smoke by removing much of the smoke residue prior to entering the smoke chamber containing the product. If you are using a smoke generator within your product chamber the smoking time should be drastically reduced to prevent what you experienced.
Personally, I disregard any mention as to how long to smoke a product if it doesn't include the type of wood, color, and density of the smoke. Now is the time to be patient.
You may find the following helpful, glean from it what you like.
There will be different opinions on how to smoke cheese. I do not intend to nitpick the issue, but I do want to help you obtain a good finished result. Understanding you have done your homework lets refresh some basics. Hard cheeses are best when kept under 80°, soft under 55°. The warmer they are smoked the better smoke penetration. Actually hard cheeses may be vac sealed or waxed as soon as any moisture if any has evaporated. I usually let mine set at room temperature overnight in a ventilated bag simply for convenience. To allow it set in open air for any longer will greatly promote mold and bacteria. Soft cheese should be vac sealed and kept at 55° or less.
Techniques will differ, but also will the results.
Tom
