72 replies to this topic

[coop]

After 3 years of operation something strange has happened. In the last month my yield of alcohol decreased by 50%. Using same formula, same yeast, same grain sources. I received a new supply of corn at the same time my yield dropped. Brix reading is the same after each mash run and after fermentation checked again brix reading is the same as usual but alcohol volume is down. Could their be something wrong with the new grain? Coop

[Whiskey&Revelry]

Easiest first thing typically is to add a Nitrogen nutrient and see if it corrects

[coop]

Whiskey&Revelry, on 24 June 2011 - 11:21 AM, said:

Easiest first thing typically is to add a Nitrogen nutrient and see if it corrects

Would "Fermaid-K from White Labs be what you are talking about?

[Hpious]

coop, on 24 June 2011 - 10:53 AM, said:

After 3 years of operation something strange has happened. In the last month my yield of alcohol decreased by 50%. Using same formula, same yeast, same grain sources. I received a new supply of corn at the same time my yield dropped. Brix reading is the same after each mash run and after fermentation checked again brix reading is the same as usual but alcohol volume is down. Could their be something wrong with the new grain? Coop

Personally, the first thing I would do is clean my equipment. A bacterial infection can at times affect your yield and before you mess with recipes or buy anything, just give your equipment a solid and THOROUGH cleaning, especially joints. then go with N supplementation.

good luck

[Whiskey&Revelry]

Hpious, on 24 June 2011 - 11:28 AM, said:

Personally, the first thing I would do is clean my equipment. A bacterial infection can at times affect your yield and before you mess with recipes or buy anything, just give your equipment a solid and THOROUGH cleaning, especially joints. then go with N supplementation.

good luck

Haha yes, good advice. Thought that was kind of a given  

[coop]

Whiskey&Revelry, on 24 June 2011 - 11:45 AM, said:

Haha yes, good advice. Thought that was kind of a given  

Yes it is a given, we run a bleach/water mix through everything once a month. But that does not mean something is on the grain. Maybe a preservative that is effecting it? Coop

[Chip Tate]

coop, on 24 June 2011 - 11:59 AM, said:

Yes it is a given, we run a bleach/water mix through everything once a month. But that does not mean something is on the grain. Maybe a preservative that is effecting it? Coop

Check all your gaskets, seals and joints on your stills and condensers for leaks.  That would be my first guess.   Chip

[will]

how's your liquifaction and sacchrification?

did you test the yeast?  is it kickin'?

[coop]

will, on 24 June 2011 - 12:44 PM, said:

how's your liquifaction and sacchrification?

did you test the yeast?  is it kickin'?

Hello Will, fresh yeast and it takes off within 2 to 3 hours, tank gets a little warmer from the reaction and by first thing in the morning I will have a 2 to 3 inch head on top. Fermentation works just like all the earlier ones. Fermentation takes about 4 to 6 days, brix goes from 15 down to 5. Coop

[Jason Parker]

coop, on 24 June 2011 - 01:06 PM, said:

Hello Will, fresh yeast and it takes off within 2 to 3 hours, tank gets a little warmer from the reaction and by first thing in the morning I will have a 2 to 3 inch head on top. Fermentation works just like all the earlier ones. Fermentation takes about 4 to 6 days, brix goes from 15 down to 5. Coop

Hi Coop,

If your starting and ending gravities are the same, (AND you know that your measurement equipment is still in calibration), then I wouldn't look at fermentation as the culprit. I'd look for a loss of alcohol during distillation.  (AGAIN, this assumes your measurement equipment is still in calibration).

Listen for hissing, smell for alcohol, and look for drips everywhere along the distillation path.

Best of luck. Please let us know what you finally discover is the cause.

Jason

[JohninWV]

Seems to me that if you are getting the same starting brix and ending brix that a huge difference of 50% would be from something in the still as Chip suggests. I would think bacterial infection would create a much smaller change than 50%.

[will]

reading from the original post, you were not getting complete attenuation prior, right?  were you satisfied with 5 brix?  (for those playing along at home, that should be about 1060 to 1020 - not good attenuation in my world).  that would suggest something else is wrong.  your short chains are not breaking-down or something else.

are you controlling fermentation temp?  is it possible that the little bugs are committing seppuku?

bacteria can be a big problem - are you making acid?

...and yes, make sure you're still is not spillin'

[coop]

will, on 24 June 2011 - 01:46 PM, said:

reading from the original post, you were not getting complete attenuation prior, right?  were you satisfied with 5 brix?  (for those playing along at home, that should be about 1060 to 1020 - not good attenuation in my world).  that would suggest something else is wrong.  your short chains are not breaking-down or something else.

are you controlling fermentation temp?  is it possible that the little bugs are committing seppuku?

bacteria can be a big problem - are you making acid?

...and yes, make sure you're still is not spillin'

Will, we have never been able to get brix down to 0, starts at 15 then gets down to 5, head drops and tank cools down and settles out overnight. Fermentation room is separate from the rest of the distillery. Temperature controlled. Separate heating system. Right now it is at 84.5 degrees F. We use open fermenters at 734 gallons each although we only put 440 gallons of wash in them along with about 700# of grain. We check for acid content during mashing and at the end of fermentation. This checks out ok. May have some type of infection going on that was brought in with the grain. Coop

[Denver Distiller]

If you don't mind me adding, coop, don't ever use bleach.  Without getting into what it can do to various metals, residual bleach can be one issue that's sticking it to your yeast.  Iodophor will do the same thing, and it's safe to use with stainless.  It rinses free, can can be left to drip dry, depending on the manufacturer.

Will's right, finishing at 5 plato is not a good sign, and that's for your "usual" run.

1st and easiest thing to do is to check calibration of all instruments involved.  All of them.  2nd is to check the alcohol content of your stillage.

[JohninWV]

Sorry, I didn't read the other post, just his first.
Todd helped me find an error (or lack of one) regarding brix. I was originally checking brix on a refractometer, but it doesn't work for finishing brix since the solution contains alcohol. I thought I had a stuck fermentation, but once I switched to brix hydrometers, I found out I was getting to zero. So instrumentation can quickly lead you in the wrong direction. Just thought I would add my $.02.

[Made in Maine]

Folks,
A lot of great thinking and debate going on here. I have to agree on the mechanical loss possibility. its a consistent amount each batch. even a small vapor leak can drain your profits. I also would be looking at the ABV of the spent wash. just to see. It does seem a bit of a short Brix swing. that would only give you 5% ABV right? I have heard that the Brix should end down around 2-3. It will be hard to bubble test the system while its hot. boiling liquid will look like a leak.
Good luck Coop,
Jes

[coop]

JohninWV, on 24 June 2011 - 03:25 PM, said:

Sorry, I didn't read the other post, just his first.
Todd helped me find an error (or lack of one) regarding brix. I was originally checking brix on a refractometer, but it doesn't work for finishing brix since the solution contains alcohol. I thought I had a stuck fermentation, but once I switched to brix hydrometers, I found out I was getting to zero. So instrumentation can quickly lead you in the wrong direction. Just thought I would add my $.02.

All help we get and give here is greatly appreciated and Todd you can tell me anything you want to. Todd where can I get what you are using? Lodophor?

A refractometer is what I am using also. So with that, is why I never get to 0. I will check with my hydrometers to confirm complete conversions.

Todd by "Stillage" do you mean spent grains? Or platform hight? coop

[PeteB]

I would like to reinforce what JohninWV said about Brix and refractometers.

A Brix reading on a refractometer is measuring the amount of bending of light, caused by whatever is dissolved in the water. It is measuring what you see when you poke a stick in the water.

The "light bending" of a brix 15 is MAINLY caused by sugars, the final brix 5 is caused MAINLY by alcohol. During fermentation the refraction (bending) is caused by a mixture of sugar and alcohol.

Some time ago I made up a 10% ABV solution of distilled alcohol and water, and from memory it read around 5 Brix.

Coop's final Brix 5 could be measuring alcohol, but the 5 could also include sugars vinegar or other nasties caused by infections.

A hydrometer has exactly the same issues.

One definitive way to measure the wash alcohol is with a "Thorpe's still", a small glass one for bench top.

[Denver Distiller]

coop, on 24 June 2011 - 04:35 PM, said:

All help we get and give here is greatly appreciated and Todd you can tell me anything you want to. Todd where can I get what you are using? Lodophor?

A refractometer is what I am using also. So with that, is why I never get to 0. I will check with my hydrometers to confirm complete conversions.

Todd by "Stillage" do you mean spent grains? Or platform hight? coop

You can get iodophor from Five Star chemicals in Denver.

By stillage, I mean after you've, as far as you know, boiled off all the alcohol in your mash, I'd run it in your lab still to see how much, if any, alcohol is left.


But before you waste your time with that, I'd check all your instruments.  Temperature, plato, etc.   And your hydrometers are just a guide for terminal gravity since once alcohol is involved, you're no longer measuring sugar% in a water solution... the alcohol throws it off.  When people say it should dip below zero, they're suggesting a guide, not an absolute measurement.  If you're seeing 5 Plato, it's actually quite a bit higher because alcohol is in the liquid, thinning it out.

And yes, by all means check your still for leaks.  Losses are one issue, but safety is an entirely different concern.

Happy Distilling

[Classick]

great problem solving here guys. A true community! Thanks for the contributions.