Molasses - stuck ferm?

[alpine]

I'm trying to make rum and I've never fermented anything other than malt, so I'm in uncharted territory here. I made a 1.083 wash with this blackstrap. A little over 4 days later it's only at 1.040. I've read that there can be a lot of variation with the final gravity depending on the molasses, but still, this seems a bit high, no?

I used 20g EDV-493 rehydrated with Go Ferm, DAP, about 2 minutes of O2, and 20g of citric acid to put the pH at 4.75. The majority of the fermentation was between 76 and 78 dF, but the last 24 hours was closer to 72 becuase I brought it down to the basement last night as the wife was sick of hearing the airlock.

So I figure I have 3 options:
1. Suck it up and strip it
2. Give it a couple more days
3. Add a few grams of Fermaid K and give it a couple more days. (the recommendation is to add it when fermentation is 1/3 complete, so this would be considered late)

Whatcha think?

[S-Cackalacky]

Check the PH again. That starting PH was a little low and it may have dropped even more during fermentation. You might also try wrapping it in a blanket/quilt to try to get the temps up a bit. Also keep in mind that rum ferments sometimes don't show accurate gravity readings - although, 1.04+ is still a little high.

[alpine]

White Labs suggests a starting pH of 4.5-4.8 - fermentation worksheet (pdf) - but I tend to agree that it seems a bit low. I put it in the garage tonight, so it'll be closer to 80 by tomorrow. Didn't know about the accuracy issue, so thanks! Looks like I have more reading to do.

[LWTCS]

Temp drop didn't help one bit.

[alpine]

Did you taste it? Sweet on your tongue? Or dry like dry wine/beer?

No, too busy being disappointed by the gravity reading. Should have at least done that and checked the pH. Lesson learned.

After some very quick reading about molasses and hydrometer readings, I may not be as far off as I initially thought.

[alpine]

Temp drop didn't help one bit.

Yeah, but this late in the show I wouldn't expect it to be too much of an issue. There was a good 72+ hours at 78.

[S-Cackalacky]

The gravity readings will usually be off because there are unfermentable sugars in the molasses. It's not unusual for a rum ferment to end in the 1.01 to 1.02 range. So, you may be closer to being finished than you might think. Work on the temp and check the PH. It won't hurt to let it sit for a little while.

[LWTCS]

The gravity readings will usually be off because there are unfermentable sugars in the molasses. It's not unusual for a rum ferment to end in the 1.01 to 1.02 range. So, you may be closer to being finished than you might think. Work on the temp and check the PH. It won't hurt to let it sit for a little while.

+1
Give a good stir. If you see the solids settle out rather quickly its prolly done.

[alpine]

I went ahead and stripped it last night. The hydro reading was about the same, maybe a bit lower. I didn't really spend too much time de-gassing the sample or anything since I was already committed. Tasted very dry, no sweetness whatsoever, so that was a good sign. pH was still higher than expected at 4.6, so I have some work to do figuring that out. Out of the 6 gallon wash, I pulled off a bit over 1 gallon of 45% low wines, which is consistent with my whiskey runs. I could have gotten more - it was still over 20% when I stopped - but it was getting late.

For the remaining washes I'm just going ferment a bit hotter, keeping it in the 80s, which shouldn't be much of a problem given the weather. I think for at least the next batch I'll plan on giving it a full week and maybe take more samples. I'm pretty anal about sanitation, though, and I hate opening the lid of my bucket fermentor unless it's time to transfer.

Anyways, I think I can label this as a success. Won't really know for a couple of months. Thanks for the help and advice!

[acfixer69]

Glad to hear a success. I almost ordered that blackstrap for my rum and am interested in what recipe you used. I have found the with blackstrap in 5 gal containers there is a great deal of separation and mixing was nesserary. I now use the whole 5 gals in a single wash because it was too messy to mix

AC

[alpine]

Recipe? Molasses, water and yeast.

I weighed out a pound of the blackstrap and added it to a gallon of water and ended up with a SG of 1.028. So it worked out pretty well to just use 1L per gallon. I didn't even think of stirring the bucket though, so now I'm going to have to recalibrate. I typically do 5 washes per spirit run, so for the next 4 I think I'm going to use 30-40% dunder.

And here I was thinking that rum would be so much simpler than whiskey since I wouldn't have to mash....

[acfixer69]

it is much easier the mashing just the first few making adjusting. I also found adding sugar to the blackstrap is better them straight molasses. I have brewer friend that sent me that way and I do like it better. I use buccaneer bob's recipe for a base and season from his essence. Try it worth the try since you are not locked in to a standard operation.

AC

[alpine]

Took your advice and stirred the bucket and boy what a difference that made. Ended up using only 3L in 5 gallons and it clocked in at 1.085. I don't think the purist in me will ever allow white or brown sugar in any of my washes. Hell, I hate using it in old ales and the likes and that's actually historically accurate!

[acfixer69]

Took your advice and stirred the bucket and boy what a difference that made. Ended up using only 3L in 5 gallons and it clocked in at 1.085. I don't think the purist in me will ever allow white or brown sugar in any of my washes. Hell, I hate using it in old ales and the likes and that's actually historically accurate!

Purist or not molasses is sugar. Blackstrap has too much after taste for me. I cut with panela and was good but did a sugar and couldn't justify wasting panela when sugar worked just as well in a sugar wash. To each there own.

AC