Low ABV day 4 of fermentation. Is this normal?

Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum

Help Support Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.


New Member
Jul 6, 2022
Reaction score
Needless to say I am new to brewing. I have done maybe 5 or 6 wine fermentation before with varying degrees of success/failure. But I am not even at the level of amateur so let it be known that I am quite ignorant in regards to many aspects of brewing, please forgive me in advance.

With that said me and a friend have started this project to create a banana rum. So we found a recipe and created a wash. Now we are four days into primary fermentation and have an ABV of 2.6% which I think is too low for that many days fermenting. My potential alcohol reading was around 15% (SG 1.102) which is no where near my current actual. (1.082) Am I just being impatient or is this an indication of an issue. And if the later how would you resolve it if even possible. I will put the specs below to give you an idea of what we did. Any help is greatly appreciated thank you!

The specs:
3.6 gal water
2 kg of brown sugar
1 gal of unsulfured blackstrap molasses
6lb of ripe Bananas (blended)
2 packets of Ec -1118 yeast rehydrated as instructed on packet at 35c for 20min
Contained in a 6 gal pale with airlock

Average temperature 23c
range 21- 26c

All above was combined and set to ferment. To this day there is no activity on the airlock.

But when I open the lid to push down the must it is fizzing aggressively, decent amount of bubbles as well.

(This is done once a day)
You don't have much in there for the yeasties to thrive on. Dump in some yeast energizer or yeast nutrient and it should take off.
naw, the sugar fermented and the molasses is only ~60% fermentable....

my best guess, is give it some time, and you should end up with about 8-9% ABV at the end....(i honestly don't know how much sugar the bannanas would contribute. but should be plenty of nutes for the yeast already.)

when i was doing stuff like that, i worried about ph, all kinds of stuff. just ended up adding a bunch i didn't need too.

just thought i'd chime and toss out an idea or two, food for thought so to speak....

edit: but i swear, all the stuff i was trying, i had a lot of fun doing it! so if you go down that hole, remember to enjoy it for your trouble!
Like others have said it seems like your water and sugar blend may be a bit lacking in nutrients - I think adding a yeast nutrient could be a big benefit since the yeast need this to "reproduce". Additionally, if you did not heavily oxygenate (stir vigorously or somehow get oxygen in the solution) your sugar solution it is possible that the yeast were not able to really get into their reproduction/proliferation lifecycle phase due to lack of oxygen present. Finally I might comment that you have a relatively high original gravity - what can happen is the yeast have trouble acclimating and starting their fermentation with this high of sugar content - you did right to rehydrate them for sure but you could also consider some kind of mini low-gravity yeast starter solution to help get them going (not sure about how good this would be for your situation).

Really it all boils down to yeast health - if they aren't working as expected they probably are all mostly dead or too stressed. Consider doing one or all of the above and just re-pitching a new batch of yeast. Hope that helps!