Bourbon Stall

[AnotherDrum]

I'm frustrated. I made a bourbon mash almost 2 weeks ago. Gelatinized the crushed corn, used winter red wheat and 2 row at 152, and a starting gravity of 1.060. I co-pitched S-04 for a few days, then added DADY with yeast nutrients, keeping pH at about 5.2 - I've been fermenting at 79 (the warmest I can get it for now), and gravity has only dropped down to 1.045. The house smells like parmeaean cheese and it has been showing signs of fermentation, but what the heck?! Is it just the fermentation being too cool?

[ckdistills]

Couple thoughts. Those temps should be fine for DADY but it's high for S-04. Did you do an iodine test to check conversion? How old is your yeast - might it be bad? Do you happen to be measuring gravity with a refractometer? Those only give an accurate reading before fermentation, personal experience there with a ferment I thought had stalled but just needed to be using a hydrometer instead.

[still_stirrin]

Parmeasean Cheese? Mashed 2 weeks ago? That doesn’t sound right.

Usually, the ferments smell like bread rising: a little sweet, yet inviting. I wonder if your winter wheat brought some lacto bacteria along with it.

Have you looked at the top of the fermenter yet? Do you see a pellicle on top?

And I too question whether or not you had much/if any conversion of the corn (or wheat, if it was raw).
ss

[AnotherDrum]

Thanks you two for responding. I did a starch/iodine test, looked good to go. I did use S-04 at the beginning but am pushing the limits on that purposely and co-pitched dady to follow behind. Trying to get some esters. I mashed two weeks ago. (Maybe closer to 1.5 weeks) My last mash had the same smell - no 'infection' or pellicle. I use a refractometer for SG but use hydrometer for any readings thereafter. My pH did have a pretty sharp drop and got down to 3.2, but made adjustments to get back to 5.2 fairly quickly. I'm racking my brain. I'm a brewer by trade, but this is puzzling me.

[AnotherDrum]

It was bubbling some before pitching the yeast..... hmmmm....

[Garouda]

Do you happen to be measuring gravity with a refractometer? Those only give an accurate reading before fermentation, personal experience there with a ferment I thought had stalled but just needed to be using a hydrometer instead.

I confirm, a refractometer will give funny results once the fermentation has started, use a triple scale hydrometer instead.
Stalled fermentation, how to restart it?
Take a pack of yeast like EC1118, 100g of sugar, 1.5g of DAP, collect 500 ml of your wort, mix with 500ml water, place everything in a suitable 5-litre container like a jerrycan.
Pitch your yeast, aerate as much as you can by agitating your jerry can vigorously, leave it for one day or less if it starts quickly, then add it to your wort…
You may add some citric acid, check your pH.

[bilgriss]

I had the refractometer thought as well, but the question has already been asked.

Here's some info: https://www.northernbrewer.com/pages/re ... calculator

[Demy]

The smell of cheese appears to be a contamination by lactic acid bacteria. The refractometer in the presence of alcohol does not give reliable results but if I read correctly you used the hydrometer during germination. Adding more rehydrated yeast may work if there is no contamination.

[Garouda]

I had the refractometer thought as well, but the question has already been asked.

Here's some info: https://www.northernbrewer.com/pages/re ... calculator

Then why not giving the answer right away, don't use a refractometer once the fermentation has started...
A useful tool: FermCalc Winemaking Calculator: https://fermcalc.com/
I use the java app on my desktop...

[bilgriss]

I've used a refractometer for years before and during fermentation for making beer. The calculated results are really close as long as you keep good notes about starting values. The thing to remember would be cases where it doesn't work - for instance, if you ferment on the grain and have residual enzyme activity, don't have starting gravities recorded, etc.

[Garouda]

I've used a refractometer for years before and during fermentation for making beer. The calculated results are really close as long as you keep good notes about starting values. The thing to remember would be cases where it doesn't work - for instance, if you ferment on the grain and have residual enzyme activity, don't have starting gravities recorded, etc.

I prefer my Stevenson and Reeves S1011 Triple Scale Hydrometer than my ATC refractometer...
Indeed, a calculator can be used to get an approximate specific gravity reading of your wort after fermentation has begun or completed.
I stopped following my SG day by day, with experience you know when your fermentation is completed. When I think it’s done, I place my Stevenson and Reeves S1011 Triple Scale Hydrometer directly in my fermenter: reading 0.990 OK, good to go. In the beginning, I used to follow my Brix day by day with my refractometer. This formula adjusts the SG after fermentation has begun, but it’s an approximation.
=1.001843 - 0.002318474*(InBrix/Corr) - 0.000007775*(InBrix/Corr)^2 - 0.000000034*(InBrix/Corr)^3 + 0.00574*(ActBrix/Corr) + 0.00003344*(ActBrix/Corr)^2 + 0.000000086*(ActBrix/Corr)^3
Where InBrix is initial Brix (OG), Corr: correction factor (1.040); ActBrix: actual (current, final) Brix
One example: readings = 16 (OG), 10 , 8 , 6.2, 5 adjusted SG: 1.065 (OG), 1.023, 1.010, 1.000, 0.993
Last value with my hydrometer 0.990, the approximation is not too bad.
The reason why I do not trust this approach is a succession of unchanged Brix values, in the above example I got 16, 10, 8, 8, 6.2, 5, 5, 5, 5. I got eight two consecutive days while the wort was still fizzling, not normal to have an unchanged SG two consecutive days if your yeasts are still active... Five would have indicated 0.993 or end of fermentation while my “beer” was still fizzling…
By the way, I have got the same ATC refractometer as the one advertised on the website you referred to.

[greggn]

I prefer my Stevenson and Reeves S1011 Triple Scale Hydrometer than my ATC refractometer...
Indeed, a calculator can be used to get an approximate specific gravity reading of your wort after fermentation has begun or completed.

I prefer my refractometer because I am not recording measurements for retail sales, where three decimal point accuracy is required, but simply checking that my process is in control.

FWIW, I have a high-precision, short range, final gravity hydrometer and haven't used it in years.

[Broken Jug]

It was bubbling some before pitching the yeast..... hmmmm....

How long did you have to wait before pitching your yeast?

I had to dump over 70 gallons of a bourbon mash/ferment that developed an infection overnight while I was waiting for the temp to come down to pitching temp. It too was bubbling the next morning before pitching my yeast.

I tried saving it by over pitching yeast, but it was a waste of time and money, there was nothing I could do to salvage it. After over a month trying differnt things to save it, I finally gave up and dumped it. It too smelled horrible. Made me sick having to dump it, never had to do that before.

Since then, I have been using ice or ice cold water to bring my temp down fast, so that I can pitch my yeast within minutes of mashing-in. Should have done it sooner.

If you haven't already, cut your loses and dump it and start over, it's how we all learn.

Good luck.

[shadylane]

I'm frustrated. I made a bourbon mash almost 2 weeks ago. Gelatinized the crushed corn, used winter red wheat and 2 row at 152, and a starting gravity of 1.060. I co-pitched S-04 for a few days, then added DADY with yeast nutrients, keeping pH at about 5.2 - I've been fermenting at 79 (the warmest I can get it for now), and gravity has only dropped down to 1.045. The house smells like parmeaean cheese and it has been showing signs of fermentation, but what the heck?! Is it just the fermentation being too cool?

Just guessing.
1.060 to 1.045 in two weeks at 79'f
Something went wrong during the mashing.

[bilgriss]

Or the crushed corn was treated with something that keeps yeast from working.

[still_stirrin]

... I'm racking my brain. I'm a brewer by trade, but this is puzzling me.

A swing and a miss, “Steeeee—-rrrriiiike”.

What does your boss think happened?

It sounds like the conditions for the yeast are off. Did you make a starter before pitching? If using dry yeast, did you properly rehydrate it before pitching? Did you aerate the wort before pitching? A long lag most often is due to some or all of these conditions. And activity before pitching is indication of wild yeast, or bacteria, getting started before you pitched.

But, as a “brewer by trade” you would certainly know how to manage yeast, right?
ss

[Garouda]

The house smells like Parmesan cheese, and it has been showing signs of fermentation, but what the heck?! Is it just the fermentation being too cool?

When I make a Bourbon-like stuff, it smells like beer not cheese, there's definitely something like a lactobacillus contamination in your wort plus oxygen that produces Butyric acid hence the smell, how was your pH? Low pH tends to hinder unwanted bacteria in your wort.
People having experience with sour mash could add to this, I've no experience with lactic fermentations.
I agree with still_stirrin, there is possibly a problem with your yeast.
When the fermentation starts, CO2 is produced, and CO2 is heavier than air so it protects your wort from oxygen, and you don't have that Butyric acid smell...
When we make beer, hopping is obtained by boiling the brew, sometimes for 90 minutes. For Bourbon, at the end of brewing I boil for 5–10 minutes, after removing the spent grain. This kills all nasty bacteria and removes oxygen. I know that some distilleries leave the grain during fermentation, but I don't, because I boil the wort after mashing, if you leave the grain to boil, tannins are released which can alter the taste.

[Stonecutter]

Do you mind elaborating on your recipe? Quantities of grist. How long did you cook the corn and at what temp? Was the corn crushed, flaked, milled to a flour? Additional Mashing time and temps for the added grist?
The more info you can give the better we all will be at helping out.

As for the Parmesan-o smell. I’m gonna have to agree that you’ve got an infection.
Who knows it may blossom into something nice though.

[Garouda]

it has been showing signs of fermentation

What do you mean by signs of fermentation? When that kind of wort is fermenting, you will notice Kräusen on your fermenter plus foam and the sound of fizzling CO2. Some people call Kräusen the whole foam of fermenting beer. The main difference with beer is that there's no hopping, for the rest, the process is very similar. Sorry for the poor quality of this picture, it's a screenshot of a WhatsApp video I sent to a friend of mine.

Krausen is typical for a grain wort or beer

The brownish sticky layer on the fermenter

I would like to add this to my previous comment about yeast. Lactobacillus develops much faster than yeast, you definitely have to avoid contamination. The way I do so is boiling the wort after mashing out. All my vessels are made of SS. For a sugar wash (TFFV), I pour my sugar into two large pots and add water, bring to boil, pour the boiling mixture into the fermenter and close the lid until the next morning. Then when the T° is close to 30-35°C I add water to the wanted level which lowers the T° < 35°C and I immediately add my yeast starter. You said 79°F that's 26°C, no problem at all !