Cigar and tobacco care has been the subject of hundreds or even thousands of tortured, sometimes totally useless and sometimes actually harmful methods and theories.

Tobacco and cigar care is simple.
The cigars or tobacco need to be stored in a sealed container. This can be a $500.00 humidor, a humble Tupperware type container or the most simple plastic bag. There are many types of humidifiers available. All of them are very effective provided you buy one that is big enough to handle the volume of the container you are using. Most humidifiers simply need to be moistened with water regularly without any other chemical cocktail.

Propylene Glycol or PG can be used in most humidifiers with the exception of the clay elements that will be harmed by PG. Propylene Glycol is a surfactant. It acts to reduce the surface tension of water to allow it to evaporate more easily. It will stabilize the relative humidity in a humidor. Is it useful? Yes. Is it essential? No, but it sure helps with a foam humidifier!

PG can be purchased in pure form for occasional recharge of a humidifier or pre-mixed PG and water combinations can be had which takes the guesswork out of how often to add PG.
I know, the title of this piece is Cigar Humidor Myths Exposed. I'll get to that now.

Myth 1

You must use distilled water in your humidor or your cigars will become hopelessly tainted.

Myth 2

70% is the only ideal relative humidity to keep tobacco and cigars stored in.

Myth 3

A humidor must have a Spanish cedar lining or it is somehow counterfeit.

Myth 4

You must take the cigars out of their cellophane wrapper prior to stocking them in your humidor or they will not taste right.

My answer to these myths may be controversial to some, dead on to others, and dead wrong to another group. I am offering my opinion based on thirty years in the cigar and tobacco industry. I have maintained walk-in humidors, 40 foot-long cabinet wall humidors, barkeep humidors for 200 cigars and my 10 cigar humidor I keep at home. I have encountered every type of problem one can imagine, and my tobacco and I have survived. So, my qualifications have been established.
Answer 1

The myth about distilled water got started by the makers of the foam-type humidifiers. Problem: tap water has minerals and other impurities that tend to clog the vent holes of these humidifiers. Solution: clean the vents! That's it! *SEE ADDENDUM BELOW* Unless you are obsessive-compulsive, you are concerned with taking care of your cigars first, and the aesthetic beauty of your humidifier second. Most tap water is chlorinated. As much as the connoisseur protests the perceived tainting of the flavor of a cigar humidified with water containing chlorine, it is better to use chlorinated water because without its anti-fungal properties, you will run the risk of building a moldy science project in your cigar box.

There are other anti-fungal agents on the market and PG has some anti-fungal properties. These products do work. Unless you think your taste buds are so sensitive that they can tell the difference between identical cigars humidified with and without an anti-fungal agent, you will be much better off using one. At least, add a couple of drops of Clorox to a quart of water, distilled or otherwise and save it to use on your humidifiers. I am not suggesting that there are not some people with a Golden Palate, but I know of none, and I sure as heck don’t have one.

...read the full guide with pics here