Stuck rye fermentation -- toss or ??

[Mr_Beer]

Stuck rye fermentation – This is the first time in 25+ years I have had a stuck fermentation.
Opinions are solicited on what I did wrong or the possibility of salvaging what I have.

Steps listed below…
15# Hazlet Rye ground to a fine meal – not powder but close to it
5.5 Gallon water ph = 6.5
Grain to water ratio is 2.7

Heat water to 158 ℉
Add hi-temp enzyme to water and stir -- 1.5 tsp (6.12 ml)

Stir in rye and mix with hand held drill mounted paint mixer as grain added
Let mash cool to 140℉. Ambient temp in the mid-70s in the work area.
Added 4 oz of 10% phosphoric acid to lower ph – result was a ph of about 4.5
Added lo-temp enzymes to water and stirred – -- 1.5 tsp (6.12 ml)
Let cool overnight to pitching temp of 79℉
Removed cover to see about an inch of foam on the top of the mash pot
Iodine check indicated conversion was complete – consistency was porridge like and grain had not settled. Very stinky.
Refractometer measurement indicated 15.5 BRIX – OG of 1.0633
Added Go-Ferm (1.5 tsp) and US-05 Ale yeast 21 package) and let hydrate at 93℉ for 15 minutes. Pitched and put cover on pail loosely to allow foaming to occur. Pail placed inside a laundry tub in case of foaming.
Day 2 sealed fermentation vessel and installed airlock since chance of foaming was past.
Fermentation was slooow occurring at the rate of about an airlock bubble per three or four minutes. Added two tsp of Fermaid K and a B vitamin.
Day 3 still no noticeable activity.
Day 4 opened fermentation pail. Still stinky but no obvious fermentation activity. Measured solution and it was BRIX of 15 – had not moved appreciably. Added 2 tsp of Red Star Distillers Active Dry Yeast under the theory that some more/different yeast might help.
Day 4 and day 5 still no noticeable activity.
Day 6 – opened fermentation pail and BRIX was still 15. Ignore the correction factors for the refractometer -- fermentation is obviously not happening.
Ambient temperature in work area is 78 ℉

I must have done something incorrect but I am puzzled...

[Bolverk]

I can't see anything noticeably wrong... is your yeast old? Can you put some in warm water with a little sugar/honey to see if it starts fermenting?

[Sporacle]

US-05 Ale yeast 21 package) and let hydrate at 93℉ for 15 minutes.

Isn't that way above the temp range for US 05,
I think you killed the yeast with the rehydration temperature

[NZChris]

Don't trust the Brix reading or the bubbler.

What is the SG?

What is the pH?

What does it taste like?

[Bryan1]

you need a hydrometer to check the stage the ferment is at NOT a refractometer as that only measures the sugar content and once the yeast is pitched put the refractometer away as it has done it's job.

chances are the ph has dropped to the high 3's and it will need a bump up so do the adjustments and remember oyster shells are the fermenters best friends

[still_stirrin]

US-05 Ale yeast 21 package) and let hydrate at 93℉ for 15 minutes.

Isn't that way above the temp range for US 05,
I think you killed the yeast with the rehydration temperature

Most yeasts will survive at temperatures near to our body’s temperature. But, if you rehydrated in a high gravity sugar solution, then the cells can explode from the osmotic pressure since the cell walls are brittle when the yeast is dry. That is why you rehydrate in water: to add water/moisture to the cell walls and to fill the cell with water so it isn’t crushed by a high gravity wort.

I’ve rehydrated dry (baker’s) yeast in water at 100-110*F before and it worked just fine when pitched into the wort.

I didn’t read if you aerated the wort when you pitched the yeast. The 1st phase to the yeast’s lifecycle is reproduction (budding). The reproduction phase is aerobic, meaning the yeast needs oxygen to reproduce to the cell count necessary to advance into latent fermentation, which is anaerobic (without oxygen).

I realize you stirred during the mashing, but that was at an elevated temperature and that limits the amount of oxygen dissolved into the mash. I usually add O2 when the wort has cooled to pitching temperature. The lack of O2 would create a long lagtime which could actually spur bacterial contamination before the yeast is healthy enough to start fermentation. Noticing several days without significant activity would be a concern that bacteria was starting to take a hold, especially if the mash smelled wrong, ie - not bready or beer-like.
ss

[Sporacle]

I’ve rehydrated dry (baker’s) yeast in water at 100-110*F before and it worked just fine when pitched into the wort.

Yeah I get what your saying SS, for me the temp that you rehydrated the Bakers at is within its tolerance range.
I just thought the temp that the OP rehydrated the US 05 at was a little on the warm side and could have killed the yeast

[OtisT]

Rye is a fickle mistress, easy to seduce, but even easier to loose.

It does seem like it never got started, but I would not give up on it. You have lots of good advice on restarting the ferment. +1 to airiating before you start the ferment. +1 to not using the refractometer and measuring by SG and/or going by taste.

You may also want to thin things out a bit if you have the chance. My experience with rye is that it contains a lot of carbs/sugar. My last batch of all rye was only 2 pounds per gallon and the ABV was well over 10% by the time my ferment ended. It also took forever to finish fermenting. (Multiple weeks). Not sure if that is a rye thing, but I typically don’t see that with my other AGs.

Good luck. An all rye is worth the effort.

[howie]

is the hazlet rye malted or unmalted?

[MooseMan]

Is it possible Mr_Beer, that there was sanitiser or some other equally yeast unfriendly chemical, in/on the vessel, or on any of the other kit you might have used?

I've done it myself.

[Bradster68]

I'm with Otis on this one. I think your ratio may be a little high. I'd do 1.5lb per gallon till you have a few under your belt.
Plus I hate to see good rye go to waste

[Mr_Beer]

Thank everyone who responded. I thought it best to elaborate a little…

General Approach
100% rye is thought to be difficult. Most experts will recommend a bottom up temperature approach coupled with several rests to get the most sugar from the grain. That requires a steam heating approach because of the (almost) absolute certainty of scorching the heating elements or boiler because of the viscosity of the mash being heated.

My approach is an attempt to do a top-down mash and get the most sugars I can without actually heating during the mash process.

So we start high and let the cooling and enzymes work as time progresses.

In this case I am using unmalted rye from the feed store with enzymes.

Refractometer Use versus Wort
A refractometer is specifically tuned to the stuff it is measuring. For the beer folks it is tuned to dissolved sugars in the wort. This is identical to a hydrometer which is also tuned to the stuff it is measuring. The results of the two and formulas to convert one to another are well known.

The viscosity of the rye based wort is very thick – think porridge (or what might be 190W oil).
There is no opportunity to get any liquid – you have portage. Hydrometers will not work. Refractometers will since you can get enough of the liquid on the lens to measure. And it works – at least it measures what it sees.

My experience is that over time the refractometer measurement (BRIX) will drop as fermentation progresses – it may not be entirely accurate but certainly will give a trend.

Yeast Hydration Temps
Fermentis recommends hydration temps at 84F max. My temp was higher based on what I have done the past 20+ years. I will lower it in the future but I am certain that all the yeast was not killed. That said, thanks for pushing my nose into the actual technical data from Fermentis.


Grain to Water Ratio
I may have exceeded the allowable/appropriate grain to water ratio. My next attempt will be 1.5 pounds per gallon as suggested by OtisT and Bradster68. This may effect the viscosity and associated measurements. Time will tell. Thanks to OtisT for his notions on elapsed time – good to know for impatient folks like myself.

As a side benefit, I can judge if the foam in the mash pot and fermenter is more or less based on grain ratios.

Final conclusion
The current wort will be dumped and I will start with a different batch. Grain is inexpensive so the cost will only be my bruised ego .

Stay tuned and an update will be published in a week or so.

[NZChris]

Your description makes me wonder if it wasn't fully converted, it should be liquid enough to be able to measure the SG with a hydrometer at this stage.

Is it sweet?

Was it ever sweet?

Have you done another starch test?

[Twisted Brick]

No judgement here, just some random thoughts...

I'm perplexed with the SG readings you got. Rye (home-malted) at a mere 17% of my bourbon grain bill was viscous enough to prohibit taking a gravity reading until I started conducting stovetop glucan rests.

There can be a difference between feed-grade and food-grade grains, feed grains are generally higher in proteins, lower in starch.

I have not worked with phosphoric acid, but some brief research revealed recommended additions of phosphoric acid were made in ml per gallon. You added 4 oz. to 5 gallons.

I would be inclined to conduct several test stovetop mashes of 2lbs of mealed rye in 1gal of water. Conduct the glucan rest, then bring to 170-175F (even though unmalted rye gels at like 135-158F). I wouldn't worry about flavor at this point - you're searching for the potential sugars available of this particular rye. Still use the enzymes, but forego any nutrients for yeast performance at this point. If you are able to take a hydrometer reading and get a worthwhile gravity, pitch some bakers and see what happens. Conduct a follow up test with minimum nutrients and pH control (let the grain do the lowering). If you get a lousy conversion, switch to the restaurant grade rye like we talked about. I've had great results with it.

[Mr_Beer]

Lots of great suggestions.

Here is an update. Try #2
Changed the grain to water ratio to 1.66 as suggested. Much lower
Followed the same basic protocol -- water to 158F, hi-temp enzyme, letting mash cool to 140F, add appropriate amounts of phosphoric acid to reach a ph of 4.5 followed by low-temp enzymes and waiting overnight for conversion.
This morning the conversion was completed according to the iodine test.
Stirred the converted mash for about five minutes with drill mounted paint stirrer backward in an attempt to add oxygen.
Mash was still thick -- about the equivalent of 90W oil; much too thick for a hydrometer. Smell was substantially less objectionable. Still about 2" of foam in the mash pot which I stirred into the mixture.
Since I am cheap, and this is an experiment, I used Red Star Distillers Active Dry yeast instead of SA-05. Hydrated yeast and added Go-Ferm and a B vitamin.
BRIX measured with a refractometer was 12.8 which is mathematically equivalent of an OG of 1.0518.

Fermentation started within an hour and as I write this is still ongoing.


Speculation and/or Observations
Water to grain ration is important. My first attempt went overboard on grain and may have had too much mash sugar for the SA-05. Pure speculation.

NZChris suggested that the mash should be thin enough for a hydrometer. This mixture is certainly not that thin. Since the grain was ground very fine, it is intermixed throughout the mash. Any notions of why it is so thick would be appreciated.

Lower water to grain ratio results in less objectionable smell and lower amounts of foam -- my guess is that at the ratio I used, the required headspace to avoid overflow of the foam is 12% to 15% of mash pot capacity. The amount is not important but the fact that you need headspace is very important so you do not need to clean up.

Rye grain and SA-05 may not work well together -- again speculation. TB could comment since he may have had some experience.

Using this 'top-down' approach avoids the issue of possible scorching as the mash is heated up. Obviously starches got converted with this approach but the conversion might not have been as complete as the different approach suggested by TB. Any comments on the conversion efficiency and how to measure same would be appreciated.


Ancillary Topics
Regarding phosphoric acid, I purchase full strength in the gallon quantity and then dilute to 10% level using a fairly complex spreadsheet. Unsaid in my brief process description, was that any acid additions are followed by mixing and measuring the resulting mash ph. The amount to add is often measured in ml but with my spreadsheet I have converted it to ounces for ease of measurement. My personal recommendation is to be VERY CAREFUL with full strength phosphoric acid -- gloves and safety glasses while handling. My opinion is that it is more dangerous than hydrochloric acid so again be cautious.

Rye grain is normally used for animal feed or planting. Only about 40% is used for human consumption. I am not convinced that restaurant grade is different with the exception that it may not be a single variety (NVS) and does not have the occasional ant crawling around in the bucket. Ground it up to very fine powder. The rye grain I used is actually seed grain and thus guaranteed to be 99.8% pure to the hybrid selected -- Hazlet variety.

[NZChris]

NZChris suggested that the mash should be thin enough for a hydrometer. This mixture is certainly not that thin. Since the grain was ground very fine, it is intermixed throughout the mash. Any notions of why it is so thick would be appreciated.

Did you taste it? If you have a decent amount of conversion, it should be quite sweet. It's an easy backup check for if the starch has been converted.

If the starch is mostly converted into sugar, the mash should not be so thick that you cant use an hydrometer to check the SG, especially after several days fermenting.

How is #2 going?

[NZChris]

Any notions of why it is so thick would be appreciated.

I've just remembered a rare one that has happened to me and to another distiller I know. A bacterial infection that causes a stringy slime that oozes off your finger like snot. I made the mistake of dumping mine, he ran his and had no trouble stripping it.

[30xs]

I haven’t worked with rye but my question would be. With it being seed grade rye, had it been treated with chemicals?

[The Baker]

Any notions of why it is so thick would be appreciated.

I've just remembered a rare one that has happened to me and to another distiller I know. A bacterial infection that causes a stringy slime that oozes off your finger like snot. I made the mistake of dumping mine, he ran his and had no trouble stripping it.

Sounds very like an infection of bakeries known as rope.
Difficult to get rid of.
I worked with a former navy baker.
When the ship's bakery became infected they headed out to sea and dumped all the equipment overboard.

Geoff

[Mr_Beer]

Thanks for the follow-up posts.. Possibly we will learn something here.

The current status is two 7 gallon fermentation episodes.

Batch 0 was discarded with no idea of why fermentation did not start.

Batch 1 has the foam and stinky (vomit) smell. It was fairly viscous -- my characterization is 195W oil. Tastes sweet but it is hard to get past the vomit smell. Fermentation took off without any issue. My tentative conclusion is that Batch 0 had too high a ratio of grain to water and overwhealed the yeast. That is my speculation.

Batch 2 was processed identically (ants and all) the same as Batch 1 but the enzymes added were about 250% more than normally used for corn.
Very little vomit smell
No foam in the mash pot
Iodine conversion indicated completion in about 14 hours -- much quicker than Batch 1.
Mixture is less viscous -- my characterization is about 90W oil.
Started to ferment within an hour with Red Star Distillers yeast and is currently bubbling away.

No way a hydrometer will work in these mashes -- too viscous. Refractometer measurements predict reasonable success -- 12.0 BRIX and 11.4 BRIX

Currently waiting for the fermentation to complete.

My notions are that the increased enzyme addition for Batch 2 resulted in earlier conversion and did something to eliminate the smell and foam. I have no idea why, just the fact of it.

Regarding rye grains in America
Grains destined for planting are specific varieties -- in my case I wanted Hazlet variety because of its properties for distilling. To my knowledge, this grain has not been adulterated in any way -- that would be a violation of America's labeling rules. That said it is possible but probably not provable or measurable. I used seed grain that farmers use every day. When you get grains that are not 'restaurant' certified from a farm supply store they are good for planting and feeding livestock. Along the way you get some debris and 'critters'. In my case there are some small ants -- they go away when the grain is ground and further processed at 160F.

Stay tuned for more information as the fermentation completes.

[Mr_Beer]

I mentioned that I would report back on the rye fermentation issues.

Batch 1 has the foam and stinky (vomit) smell. It was fairly viscous -- my characterization is 195W oil. Tastes sweet but it is hard to get past the vomit smell. Fermentation took off without any issue. My tentative conclusion is that Batch 0 had too high a ratio of grain to water and overwhealed the yeast. That is my speculation.

Batch 2 was processed identically (ants and all) the same as Batch 1 but the enzymes added were about 250% more than normally used for corn.
Very little vomit smell
No foam in the mash pot
Iodine conversion indicated completion in about 14 hours -- much quicker than Batch 1.
Mixture is less viscous -- my characterization is about 90W oil.
Started to ferment within an hour with Red Star Distillers yeast and is currently bubbling away.

No way a hydrometer will work in these mashes -- too viscous. Refractometer measurements predict reasonable success -- 12.0 BRIX and 11.4 BRIX

The results are in for both batches after the fermentation was complete and the result squeezed and is settling.

The OG was low but that probably had to do with my low g/w ratio. I can fiddle with that in the future.

The mashing process started with water at 158F and high temp enzyme then cooling to 138 and low temp enzyme and sitting in mash pot overnight to allow adequate time for conversion. This is essentially a 'top-down' approach since I do not have any steam heating to raise the temps during the mashing process. The goal was to see if I could get a rye mash that I could ferment with a traditional approach to mashing.

Neither batch had any particular vomit smell after fermentation.
Both batches fermented to 1.006 -- fairly good result in my view.

Batch 1 was more viscous and I was able to extract about 5.2 gallon from an input of 7 gallon. It was slimey which made squeezing more difficult.
Batch 2 was less viscous and I was able to extract about 5.3 gallons from an input of 7 gallon. It was less slimey than Batch 1. This batch had the 250% enzyme dosage which seemed to make it less viscous and the squeezing/extraction was a little easier.

Again thanks to everyone who provided input.

Next round I will be using some ViscoSEB L – Beta-Glucanase Enzyme. The results may be even better -- less slime.

[vernue]

I've learned a lot from this thread. Thanks for sharing experience and wisdom.

Looks like you've been traumatized from a rye scorch or two. Same here. After about two years of working on this, I figured out that my 50 l still bottom fit inside my 35 l cooking pot (the first is tall and skinny, the second more like me, short and rounder) with just enough room for some water in between. Double boiler method has been my go to for cooking rye, and with patience, for the stripping run as well.

I'm kinda undecided on how effective the glucon rest is, though. Or even visc-flo. It's better that nothing, but I've resigned myself to rye just being a nasty mess to make. I do think that the longer one holds for the glucon rest, the more effective it is. I shoot for 90 minutes minimum.

While it's true that the slimy viscous mess of a rye mash makes using a hydrometer difficult, I can usually get something for a reading by straining a cup or so through a mesh bag. While still thick, i tap the bottom of the cylinder til it stops moving. I also just got a tilt hydrometer, as a way to get two readings and compare. If using a tilt hydrometer, make sure the tilt in not just sitting in the foam, but actually floating in the wort underneath.

I'm just finishing up a 200 l mash of 70% rye 30% wheat, and have already ground the grains for a 60/20/10/10 corn/rye/wheat/barley 4 grain bourbon. I'll do the rye and wheat separate, adding in the malted barley at end, and the corn I'll convert with enzymes.

But I am realizing that the true art in whiskey making - aside from making cuts - is fermenting.

[vernue]

One of my rye/wheat mashes fermented out dry - .985. the other is stuck at 1.025. I've tried warming it, repitching, fiddling with the pH, repitching... it smells fine, seems thin and clear (as was the other: I take back my doubts about the beta glucon rest). It tastes sour, like it's ready to go.

I'm thinking to give it a little while longer, then squeeze and strip. Since it seems like it might be low in ABV, I was thinking of cranking up the % by adding some heads from a previous rye run. Is this a good idea?