Rum Fermentation Failing

[Rancastar]

Guys i desperately in need of HELP. We started fermenting the Sugar Cane Juice to make Rum and the SG was 1.072 ( thus about 17 brix). It took off nicely then all of a sudden died after two and half days. I checked the SG and it had dropped to 1.048 (thus about 13brix), we used Calcium Carbonate to up the pH as it kept dropping and kept temperature inbetween 28 - 35 degrees celsius. We also added Nutrivin to boost the yeast and did everything according to the letter. 

I have been reading through and I came across something you call a buffer solution used in fermentation, can someone please explain to me what it is and what quantity I must use in a 1000 litres Sugar Cane Juice fermentation ? Secondly what pH is ideal for yeast fermentation ( SafSpirit C-70 or Distillax RM) and what could I be doing wrong.

[stillwagon]

Calcium carbonate doesn't raise pH much. I use it as a buffer to prevent a pH crash.

Calcium hydroxide will effectively raise pH, but do it slowly as it is very reactive and you can overshoot quickly. I keep my pH above 4 to keep it active,

fermentation is usually done in 5 -6 days at 80f.

I would avoid the buffer solution. They usually don't work very well in my experience.

[bluefish_dist]

You can create your own buffer by adding equal amounts of calcium carbonate and citric acid.  Calcium doesn’t dissolve very well in water and adding acid will dissolve more.   I found that I like having the water buffered enough that the ph would fall from 5.2 to 4.0 in 24 to 48 hours.  Then hold at 4.0 by adding cc or other ph boosters.  Because I used molasses and sugar the mix between the two would change how much I buffered.  Molasses had calcium in it, so more molasses, less buffering was needed.  

Straight sugar tends to need a lot of nutrients.   As I never ran cane juice I can’t say how it compares, but using evaporated cane juice (aka raw sugar), it needed more a lot compared to grain, 2-4x as much.  

A few more things to consider, do you do step additions of nutrient?   Say 60% at pitch, 40% at 24 hrs?  Also pitch ph can make a big difference.  Make sure it’s 5.2-5.4.  

[Silk City Distillers]

Fresh cane juice is pretty unstable from a microbiological perspective.

Whats your yeast pitch amount and how fast are you pitching post-pressing?

 

[Rancastar]

Hey guys, thanks so much for the awesome response.

We pitch half of the yeast and add a quarter after 24hrs, and then another quarter the second day. We also did the same for the nutrients, thus half at first pitch and then half after 24hrs, and then the last quarter the following day.

@ Silk City Distillers - sorry can you elaborate for me, what you mean by fresh cane juice is not stable and how could this have affected my fermentation, and what will be the best medium to use for Rum Fermentation ?

Can someone take me step by step of how you guys ferment to make Rum, and what is the best medium to use ?

[Silk City Distillers]

While you can stage your nutrient additions, you can not stage your yeast additions.  Pitch all your yeast at once.  For 1000 liters of cane juice, pitch a brick of yeast (500g).  In cane juice this needs to be done as quickly as possible post-press.

Cane juice is full of wild yeast and bacteria, it will begin fermentation immediately upon pressing.  If wild yeast outcompete your pitched yeast, alcohol levels may retard the growth of your yeast in comparison to wild yeast, leading to a stalled fermentation.  If bacteria outcompete yeast, pH will plummet quickly and retard yeast growth.  By adding nutrient and not all the yeast up front, you are providing an advantage to the wild yeast and bacteria.

[Black Creek]

Excellent thread. I have not used fresh press but do intend to in the future. Right now I am using panella and no nutrient. I have used distillivite with distillimaxrm previously and between the two I do not see any difference in ferment times. I am in Florida so the warehouse is nice and warm. Ferment stays about 84 degrees give or take. Right now my ferment takes over two weeks after which I clean sediment from wash and run. I keep daily checks on brix, sg, temp, ph. ph stays over 4. How are the rest of you getting 5-6 day ferments?

[Skaalvenn]

2 hours ago, Black Creek said:

Excellent thread. I have not used fresh press but do intend to in the future. Right now I am using panella and no nutrient. I have used distillivite with distillimaxrm previously and between the two I do not see any difference in ferment times. I am in Florida so the warehouse is nice and warm. Ferment stays about 84 degrees give or take. Right now my ferment takes over two weeks after which I clean sediment from wash and run. I keep daily checks on brix, sg, temp, ph. ph stays over 4. How are the rest of you getting 5-6 day ferments?

What starting gravity are you at?  How much yeast into how much wash?

We go from 1.080 to dry (1.015 to 1.025 depending on molasses amount) in about 30 hours.  2 weeks is way too long.

 

[Black Creek]

Starting gravity 1.07, 17 brix, 200 grams yeast into 130 gallons water which fills fermenter to 150 gallon mark after adding panella at just over 2lbs per gallon

[Skaalvenn]

5 hours ago, Black Creek said:

Starting gravity 1.07, 17 brix, 200 grams yeast into 130 gallons water which fills fermenter to 150 gallon mark after adding panella at just over 2lbs per gallon

That SG should be spot on. Your yeast is a bit light, but you shouldn't have as bad of a problem.  I haven't used RM in a couple years, but I think 84 might be a little too low? Try it in the low 90s and see what happens.  Do you add your yeast to warm or cold water?  We pitch our yeast at around 95.

Does it take off? You should have good action within a few hours of pitch.

[Black Creek]

I pitch as close to 100 as I can get. I start yeast in a bucket until cake forms then pitch. Within a day it is rolling. Active all the way thru fermentation. It is about to be in the high 90's to 100's here on the daily in summer so if the next ferment shortens that should tell me what's up. Might have to coil some copper and make an immersion heater to see if it helps. Was planning on doing that this winter any way, lol. Perhaps another yeast? Slow ferment has been giving good results in spirit but I have distributors knocking on my door now so I need to increase my productivity in order for wholesale to make fiscal sense. Next step is adding a stripping still to match my fermenters. That should double my efficiency as far as time goes. Thanks.

[Skaalvenn]

8 hours ago, Black Creek said:

I pitch as close to 100 as I can get. I start yeast in a bucket until cake forms then pitch. Within a day it is rolling. Active all the way thru fermentation. It is about to be in the high 90's to 100's here on the daily in summer so if the next ferment shortens that should tell me what's up. Might have to coil some copper and make an immersion heater to see if it helps. Was planning on doing that this winter any way, lol. Perhaps another yeast? Slow ferment has been giving good results in spirit but I have distributors knocking on my door now so I need to increase my productivity in order for wholesale to make fiscal sense. Next step is adding a stripping still to match my fermenters. That should double my efficiency as far as time goes. Thanks.

Hmm.

Are you oxygenating the wash?  You don't need to pump in oxygen, but vigorous action to dissolve oxygen into the tank might help (yeast need oxygen at the beginning in order to make more yeast).  I've talked to some distillers that try to boil off chlorine, which also reduces dissolved oxygen and that can result in slow ferment.  I don't have the greatest understanding of yeast, but everything I've heard says they need oxygen to divide, and once oxygen is depleted then they start creating alcohol.

I would imagine panela has plenty of nutrients, but you could try adding some.  If you're already adding, you could try using less or none at all (I'd try either option in a much smaller batch first).

Also, what gravity readings are you seeing throughout the ferment?

[Black Creek]

Couple of my first ferments I used distillavite, dap, baking soda, etc. and then ran clean. Just water, yeast and panela. Same times for both. My water is artesian and according to meter very clean, ph around 8 at tap with tds of 184. It gets some serious oxygen when I melt the panella in with a drill and paddle I bet. My lallemand rep tells me 84 degrees during ferment is right in there and I may want to pitch less than 95 degrees. Gravity starts around 170 and falls steady with ferment. At three weeks or there about I am at 1 brix or less and then rack n run.

[Crooked Creek]

Where do you source the panela. I'm making a sugar wash moonshine now, but want to make a rum. What are good sources for the panela, and molases?

[bluestar]

16 hours ago, Crooked Creek said:

Where do you source the panela. I'm making a sugar wash moonshine now, but want to make a rum. What are good sources for the panela, and molases?

There are molasses producers and wholesalers throughout the country. Check with any supplier of sweeteners for the baking industry in your area, for example.

[Sugar Daddy]

We make Panela.

Located in Florida for pickup or also ship.

[Black Creek]

Sugar Daddy is where I get my panela. Jason is great to work with.

[Black Creek]

So the heat has come home to Florida. Ferment hit 90 degrees and finished out like a race horse. That answers that question. Come fall I guess I'll be needing to build an immersion heater or two.

[bluestar]

On 6/6/2019 at 7:36 AM, Rancastar said:

Secondly what pH is ideal for yeast fermentation ( SafSpirit C-70 or Distillax RM) and what could I be doing wrong.

According to Lallemand, RM should be good for 3.3-5.3. But we found that if you get much below 4, you are at risk of shutting down fermentation.

[Gundog48]

On 6/6/2019 at 3:57 PM, bluefish_dist said:

You can create your own buffer by adding equal amounts of calcium carbonate and citric acid.  Calcium doesn’t dissolve very well in water and adding acid will dissolve more.   I found that I like having the water buffered enough that the ph would fall from 5.2 to 4.0 in 24 to 48 hours.  Then hold at 4.0 by adding cc or other ph boosters.  Because I used molasses and sugar the mix between the two would change how much I buffered.  Molasses had calcium in it, so more molasses, less buffering was needed.  

Straight sugar tends to need a lot of nutrients.   As I never ran cane juice I can’t say how it compares, but using evaporated cane juice (aka raw sugar), it needed more a lot compared to grain, 2-4x as much.  

A few more things to consider, do you do step additions of nutrient?   Say 60% at pitch, 40% at 24 hrs?  Also pitch ph can make a big difference.  Make sure it’s 5.2-5.4.  

Would you be able to share some methodology here? I'm also looking to achieve the same thing, keeping the pH at about 4 after 48 hours. What quantity of calcium carbonate and citric acid are you using to create your buffer, and how much do you add to the fermentation? I know it depends on the total acid levels in the wash, but it would be good to get a starting point.