I've been growing gourds in zone 5 for 6 - 7 years. Freezing doesn't hurt them. I always loose a few to rot. They are usually the ones that weren't quite mature when the first frost hit. Mold on the outside is a normal part of the drying process and isn't harmful. That's what gives the dry gourd their wonderful shading. If the mold bothers you, you can keep wiping them down with bleach/water solution, but I've never been able to keep away all of the mold so I quit doing that. I leave my gourds outside all winter, right in the garden where they grew. By spring they are lighter to move, and the exposure to the weather has cleaned most of them. Gourd growing is addicting. Come join in the fun!

thank you. I then will wait until they are very dry - tomorrow morning and put them back into a shed on pallets- OR DO YOU THINK OUTSIDE WOULD BE BETTER? thanks again= Celia

Amen, country-blooms

Only immature gourds(of the lagenaria type) will rot.
Some controlled mold growth can give the gourd a nice patern.
Wiping with vinagar is also another way. Most of my Bhouse and bottle gourds are mostly dry and the seeds rattle.
But I have some large SWAN gourds that are still hanging green(splecled) and are heavy.

Thank you both. The gourds have been washed and dried. Some were thrown away. Some aare discolored- they look partly water damaged if that nmakes sense- large circles of darker green. These I still have inside and the rest are back on the pallets. It has already snowed here. They will freeze soon but not be covered by snow as they are sheltered. I take it then that they will either be mature enough to make it or rot because they did not have a long enough growing season. Correct. Thx, Celia

Water will never damage a mature gourd from outside.
Discoloration is normal. All BH gourds will turn light brown if no molds were there. Discolorarion done by molds will be anywhere from black to brown and many shades and patterns in between. No artist can duplicate what molds sometimes create.
If you don't like discoloration done by molds, you can wet them and scape the outer thin layer(w/back of plastic knife). The main shell MAY have some effects of the mold stain. Again, it will prettier that being uniform and bland, to me.

Last year I scraped the outside layer of my gourds off as I cut them off the vine, prior to drying them. Someone on this forum mentioned doing this-I don't remember the poster's name. Scraping them helped my gourds to dry quicker and I didn't have a mold problem. I do turn the gourds during the drying process in case moisture is trapped beneath them. I wouldn't bring them inside to dry.