Mold in glass bottles

We have had mold issues when using specialty glass (maple leaf and basquaise bottles) also before we started preheating the glass. Now a must to preheat all glass before bottling.

I always preheat the bottles in a water bath and lay the bottles on their side to heat sterilize but also just to make sure they seal. I also bottle glass closer to 190* because the glass cools soooo fast.

I usualy warm my bottles on top of the canner or steam hood, and bottle about 190 deg, haven't realy had any big mold issues and the only ones that I did have at one time were on 8 oz glass, after closer examination I believe it was because of how the caps fit on the glass threads. seems some of the glass would have a sealing surface that wasn't perfectly flat and would seem sealed but realy wernt, if the bottles were left on the side they would weap syrup on a few over time.

Forgive me if some of my questions are out there, this is all new to me. Does this also happen plastic bottles ?An should the plastic bottles be warm up ?

the plastic doesn't absorb and dissipate the heat the same as the glass does. I put my plastic on top of the canner but that's about it. since its so thin it heats very fast. It more important to fill the smaller bottles both glass and plastic quickly and get the lids on quickly to seal as they both cool very fast.

I have had the same problem in the past with mold in the smaller 8oz. glass bottles also,only 1 or 2 out of about 18 has this happened to and not all the time.I preheat the bottles in a water bath and the syrup to 185 then bottle it.Being only a hobby setup I don't have a lot at one time to bottle but was wondering if after I bottle if I put them back in the water bath for awhile to heat back up if this would help and has anyone ever done this with any better success.I wonder if as someone said the bottle top is not even and I'm not geeting:confused: a good seal.

I use a water-bath canner to can small bottles from larger containers. Just full the bottles with cold syrup and put them in the canner. Keep syrup down in the neck to allow for expansion. Fill canner with water to neck of bottles. Insert thermometer into neck of one bottle. Turn on heat. When therm reads 185, remove bottles one at a time and cap them. Lay on their sides a minute or so. I use a rubber glove on one hand. Real small bottles I fill with a plastic squeeze bottle. I also use this to top off any size bottles just before 185 degrees. You can squeeze out just a few drops, if needed. I think there is less chance of mold if the bottles are filled to the very top. They will recede when they cool.