It came out good. I have never drank much rum, but I heard this stuff was relatively easy to make, so I thought i'd give it a try.
In a 6.5 gallon food server bucket, combine:
5 gallons of 85-90 degree water.
- Use either a mix of R.O water and tap water, or i've read that clean, filtered rain water works better than this. The reason the rain water works so well is it's a little bit acidic and helps keep the molasses from screwing up the ferment. I didn't have any rain water saved up, because I live in AZ and it's a desert here.

I used 1/2 tap water and 1/2 R.O. water. It came out fine. It just took a little longer to finish the ferment.
4 multi vitamins. Doesn't matter what kind, just crush them up and toss them in the bucket.
12.5 lbs of brown sugar. You can use less, and it will finish faster if you do, but I bought a 25lb bag and because it's a PITA to store, I wanted to use it all in just 2 runs. Add the sugar into the water slowly. Brown sugar clumps pretty bad and it will spash if a big clump hits the water too quickly. Continue stirring the brown sugar for a good 5 minutes after it's all in there.
1/2 gallon of light sweet molasses.
IMPORTANT!!: Taste it! It should be mostly sweet and have very little bitterness to it. I got mine @ smart and final. Feed store molasses you're probably taking a chance on it being backstrap molasses, which doesn't have enough sugar left in it to make good rum.
If the jug is cold, warm it up however you have to. Once you get most of the molasses out of the jug, pour 1 cup of really hot water in there and shake the s*** out of it. Otherwise you'll be waiting half the day for all the molasses to drain out of the jug.
Add to your brown sugar/molasses/vitamin water 1/2 a satchel of turbo yeast (the kind you make vodka with). This probably isn't ideal, but it's what I used and it worked ok. They do have special yeast for making rum, but I didn't have any.
The ferment will probably take ALOT longer than you're used to. Something about the molasses makes it go slowly. Mine took 2 weeks to get from 1.110 SG down to .99. Expect anywhere from 10 days to 21 days, unless you use a PH reducer or rainwater for your mash.
Once it's done, it will smell like a really, really, really cheap wine.
Distilling:
The first run I did, I tossed the first cup of distillate and still got over a gallon of product. The stuff that I collected at the beginning of the run was 140 proof, and the stuff at the end was 120. This is a very conservative cut and you could probably get more if you know what you're doing. I have collected stuff to drink before all the way down to 110 before and i'm not dead yet.
I didn't get greedy because a gallon of 130 proof rum for ~$10 cost is plenty for me.
The rum I tasted from this came out right out of the still tasting surprisingly good. It tasted alot like vodka, but it has a definite sweet flavor to it. Once my second run is done, i'll probably toss about half of it in one of my charred barrels for some aging.
Good luck and let me know if you try this or have any questions.
Matt