1. "Glycerin is not compatable with sun rendered fish oils." Bob Jameson
2. "Glycerin also will not mix with BTO. Nothing energetic like mixing fish oil and urine, but they will separate back out into layers almost immediately." bearcat2
3. "

Oils and waters never stay blended, an unfit union, never to become one. Different weight oils will also stratify when blended. Some very quickly, others in a short period of time.

BTO doesn’t play well with anything.

If you used an emulsifier to blend glycerin with fish oil, would the glycerin retain its antifreeze characteristic?

Some fish oils have a very low freezing point. So low the glycerine would not actually be needed. Some gel without freezing hard. In my opinion antifreeze is only needed so the contents don’t break the bottle and the product can still be applied.

Early in my luremaking career I thought I needed glycerine in everything. I’ve learned to use it only when needed.

I’ve also found it can drastically change the odor of a few bases and it can also mute odors if used in too high of quantity.

Trout oil will not freeze like water in below zero temps. Pure trout oil will begin to thicken and get very viscous as the temperature drops near the mid 50 degree range.

Even when extremely cold it still gives off the same odor, it will need to be applicated with a knife or stick and will hold fast. Once that paste is smeared upon an object it is hard to beat for a long term durable attractant. I have found it is not good to cut a high quality pure fish oil with uncompatable materials.

Keeping your application bottle in your pocket or on the dash of your truck will keep it flowable. I keep mine in a zip lock baggie with a paper towel inside to reduce leakage and spillage.

I found a workaround with the lure base I've been working on. The base is fermented eggs and trout oil. I added a bit of glycerin to help with freezing. Sunflower lecithin and guar gum. So far it's working and hasn't changed the scent profile.

my go-to sweet marten lure is 4:1 BTO/fish-oil based with emulsifier, guar gum and some glycerine to keep the polar (water-compatible) fraction of the lure from freezing/crystallizing.

It works and stays usable (neither runny nor too solid) in the working temperatures which are usually between 0 and -25C (~30 to -15 F). Too much glycerine seems to create a film in cold weather that seems to lower the vapor pressure of the mix.

But I'm no expert.

Tatiana,
Is that a smearable, paste type lure or is it more of a liquid/gel that is squeezeable?

I've made both versions, depending on how lazy I am. When I'm not, I add rotted down glands that I rub through a fine sifter. When I am, I just put them there with all the leftover hairs and chunks left after grinding. Same with ground castors vs castor tincture. I actually turned one big jar of sweet/musky lure into a "forever soup" kind of project, I kept refilling it with the base ingredints in the original proportions gradually, wile also adding some optional almost-solids such as glands, ground castors, raw mumiyo or old wild straberry jam, and noted the synergies and nuances I liked.

Unless you have compared the change on coyotes you dont really know if its changed the scent profile. Their sense of smell isnt anything like ours. We consider glycerin odorless but it can and will be detected by coyotes. Ive tested it over and over.

Another tip is eggs are a pretty good emulsifier themselves (one of the reasons they are used in cooking recipes) that ALSO add attraction to a predator formulation

Is there any reason to add lecithin to eggs if eggs already contain a ton lecithin? Also, bacteria decompose lecithin primarily into fatty acids and glycerin (among other things).