Here is a brief description of how I make dip... along with some explanations a long the way.
1. Pack a mason jar with shredded tobacco to which I have added a salt/water mixture to get it nice and moist (not sopping wet)
2. Cook for 8 hours at 185F. I'm not sure why you would want to do a double cook but for dip it would be a waste of time.
3. Pour hot tobacco into large metal bowl and add glycerine/sweetener.
4. Let cool/age for about a week. ( I keep the bowl on a counter top with a lid partially covering the bowl. I fluff up the dip once per day.
5. After about a week or two I will separate the dip into smaller batches and add my various flavorings.
So.. I like Yellow Twist Bud for my dip. It is fairly light in nicotine. I do not use any type of pH altering stuff such as sodium carbonate. Originally dip (snus etc) was made with up to 50% ground up stems. Stems have essentially no nicotine so I believe manufacturers started adjusting the pH in their mix to increase the nicotine absorption due to the stems. You do not need Sodium Carbonate for dip. I think this whole pH adjusting chemical thing began hundreds of years ago. Tobacco manufacturers had tons of stems left over from stripping the leaves for chew and pipe tobacco. So, what do you do with tons of stems? Use them as filler for dip. But that would make a weak product due to the low nicotine so add some Sodium Carbonate to increase the uptake of nicotine. This is a good example of a manufacturer turning his potential waste material into a profit instead of a loss.
For a sweetener I use Xylitol and pure Sucralose. Since I am going to have dip in my mouth I do not want to use sugar. Xylitol has excellent anti-tooth cavity properties as well as anti-microbial properties (the two being related).
The Glycerine is two fold. It has good anti-microbial properties and it adds "mouth feel" to the tobacco. This means that when you put dip in your mouth, all the flavor will not be sucked out in 30 seconds.
The reason I add my flavoring last is because I like a lot of variation in my dip. Sometimes I desire wintergreen, other times black licorice or even orange flavored. I usually make a big batch and after aging, break it up into smaller batches and store in the freezer. This is completely finished dip with the exception of the flavoring. If I am dipping wintergreen but have the urge for some apple cinnamon I just thaw a baggie of unflavored dip and add my flavoring.
Dip is easy.. don't over complicate things. As a matter of fact, you don't even need to cook your dip at all. That's just done to kill off any enzymes/bacteria that cause a rise in TSNAs.
If interested, let me know and I'll post my recipe (with quantities).