Jump to content
Patio29Dadio

Weird Low Yield Problem

Recommended Posts

Running into a weird problem.  Our standard rum process started delivering very low yields and we cannot figure it out. 

The wash is 50% cane sugar and 50% premium dark molasses.  We dissolve in (filtered) hot water, and then add (filtered) cold water to get to pitching temp of 90 degrees F.   Starting brix is 19 and PH is 4.9 (after adjustment).   We add a yeast nutrient blend day one and another smaller dose day two.  Four day ferment with temp kept at 85 - 90 F.  Ending brix of less than 1 (.08 from hydrometer and Anton Parr DM35).  Ending PH is 4.2.  Strangely the refractometer is giving us a 7 brix reading.  Wash has no notable sweetness indicating good conversion confirming the brix differentiation readings (except for the refractometer); however, the stripping run yields are about 60-70% of normal. 

The only variable we can come up with is a colder fermentation... this time of the year we are running around 85 degrees instead the typical 90 we maintain during the warmer months.  However, this does not explain the low yield relative to the start and ending brix measures unless something is messing with the hydrometer and Anton Parr readings.

Any ideas?

Share this post


Link to post
Share on other sites

Does it have any different aromatic or flavor qualities? If so it might be an infection of something. Seems like you would notice it though as that would be heavy to lose that much ABV and the pH is still fairly high.

How long are you fermenting? Are you using a standard yeast or something funky or repitched?

Share this post


Link to post
Share on other sites

Here is the answer.  Never trust the hydrometer in the parrot. It was defective and causing the distiller to kill the stripping run too early.  Going forward the process will require hydrometer reading (after testing it to make sure it is accurate) AND head temperature reading.  

Share this post


Link to post
Share on other sites

I do raw sugar washes mostly. What jumps out at me is the PH of 4.2. It seems high to me (I normally finish around 3.5) and In conjunction with the ferment temps and relatively quick finish time (take me about 5-8 days to finish and keep temps at those levels) maybe you are not quite dry yet?

 

has activity stopped at that point?  What does your hydrometer tell you?

 

 

Share this post


Link to post
Share on other sites
14 hours ago, FijiSpirits said:

I do raw sugar washes mostly. What jumps out at me is the PH of 4.2. It seems high to me (I normally finish around 3.5) and In conjunction with the ferment temps and relatively quick finish time (take me about 5-8 days to finish and keep temps at those levels) maybe you are not quite dry yet?

 

has activity stopped at that point?  What does your hydrometer tell you?

 

 

We have a consistent 4 day ferment where we go from 19 brix to -2 brix.  About the best I think we can do with a 50% sugar / 50% molasses wash.  Turns out we were having standard results but just using a broken hydrometer and relying on it to tell us when to shut down the stripping run.  We usually stop the run when the parrot is at 15% abv as the energy cost to keep going are not worth the remaining yield.  We had a couple of runs were we mistakenly killed the stripping run where we probably were are 30-35% abv.  That accounted for the low yield for the runs. So the lesson learned is to test the hydrometer and also rely on another control point (column head temp) to decide when to kill the strip.

Share this post


Link to post
Share on other sites

Patio - I've gotta ask a follow up question.  Is the temperature of the distillate at the parrot changing?  At my old gig we'd have considerable changes in the coolant temp, which obviously makes changes in the hydrometer reading.  Just a thought. 

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×
×
  • Create New...