Why go to all that trouble? Just put them into a zip-lock bag and freeze, they will hold up for months without any effort.

Because I don't want to have to defrost when I want to use my basil. It's far less trouble to sprinkle some dried in than to remember to get it out long before I'm ready to cook with it.

That is no problem it does not need to be defrosted just toss some into what ever you are cooking.

I chop it in the food processor with a little olive oil and freeze it in ice cube trays. Once frozen I just pop them out into a freezer bag. I can either toss in a cube to a recipe or thaw it in the microwave. I use it like this to make pesto, and all the wonderful flavor is maintained. More than anything else, I have always been disappointed with the flavor when I dry basil. It just doesn't work.

when freezing basil pile leaf ontop of leaf,place in small baggie . then roll to extract any air and water remaining. place each baggy in one large freezer bag. when in need take one bag out of freezer and crush . it's very brittle I just move bag continues back and forth with both hands.

you also have a fresher taste than dried . dry leaves should be removed before serving for safety issues. people have been known to choke on dried leaves when ingested.

but the answer to your question is it's not mold just the drying process. best of luck

The aromatic oils in basil are very volatile. They lose flavor very quickly when dried. I agree with the other posters - it's better to freeze them. I chop the leaves and roll into a cigar shape. Each 'cigar' is wrapped separately in plastic wrap and all of them are stored in a plastic freezer bag in the freezer. When I need some, I just unroll it, chop off what I need, recover the remainder and toss it back in the freezer.
This works well with fresh grated ginger and other herbes.

I don't use a dehydrator to dry herbs, i just place in serran wrap not tied closed in the sun...

basil is the one herb I wouldn't dehydrate. It's flavor disperses so quickly, I don't even like to cook it, just add it to the super hot food after removal from the fire and stir in to wilt a bit.

I have not tried to preserve my fresh basil, but would likely do the olive oil in ice cube trays....there are super mini ice cube trays available.

For those who have done this - is the olive oil solid? Or is it like a jello type thing? ie can you pop them out and store in a baggie, and later just grab out individual cubes?

Basil, like a few other herbs (cilantro, lemon balm, pineapple sage) do not dry well.

the traditional method of preserving basil is in crushed in oil (think pesto without the nuts) and I have found that this freezes well - I have a ice cube tray with 'bullion' sized cubes that I use for this.

the stalks left from stripping the leaves can also be crushed and used to infuse vinegar - this is particularly nice with rice vinegar.

chinacat...never thought of doing the stems that way but agree the flavor in the stems are wonderfully tasteful.
I usually save the stems and mince with a head of garlic for a spread with crackers and cheese.

I chop the basil and freeze it in regular sized ice cube trays with a little water. Once frozen, I pop them out and put into plastic freezer bag. I can just throw a cube into food while it's cooking, or thaw it in a strainer to get the water out.

Might have to try the cigar rolling method. Sounds interesting!

I put fresh basil, garlic and olive oil into food processor to make a paste, then freeze in ice trays. Store frozen cubes in ziploc container. This is terrific in sauces. I'm planning to add fresh parsley to the mix next season.