You don't want to 'spoil' it by adding guar gum but you'll use glycerine? I don't see the problem with using a plant extract like guar gum but if you're adamant there was a great feature on Serious Eats (too long to quote in entirety but worth reading in full) about making ice cream without an ice cream machine which goes into great detail on preventing excess ice formation:
So how could I reduce both crystal formation and overrun even further?
A thought struck me: I knew that when freezing meat or fish, the more rapidly the food is frozen, the less cell damage there is due to ice crystal formation. Would speeding up the rate at which the ice cream base froze help me minimize crystal formation as well?
The rate at which a given volume changes temperature is dependent on the temperature of its surrounding environment, as well as the amount of surface area exposed to it. There's no way for me to get my freezer to get any colder, but as it turns out, there's a simple device that is custom designed to freeze liquids in your freezer as fast as possible: an ice cube tray.
The only problem that remained was: who the hell wants to eat ice-cube shaped ice cream?
The solution was as simple as throwing the cubes into a food processor:
In fact, whirling it in the Cuisinart gave me another distinct advantage. I could save the unwhipped portion, freezing just a base of eggs, sugar, evaporated milk, and whipped cream. This cut back on the water content of the mix, further reducing crystal formation. I could then add the cream and the cubes of ice cream directly to the food processor. By doing this, ice crystal formation went down to virtually zero...
The actual recipe is here: