Stalled Oak Fermentation?

PowerHobo

Chalcosoma
So, I've got (most of) a 20lb back of Traegar oak pellets split into 3 5gal buckets. The total weight was about 34lbs including just barely enough moisture to be comptactable. About 7lbs of all-purpose unbleached flour went in, and a small packet of yeast per bucket.

The buckets are kept in a room at 80f. After a couple days the buckets definitely got warm, but not hot, and the buckets smell strongly sour/sweet like wine.

That all lasted for about two weeks. I've been mixing the buckets daily, but the buckets are back to about room temp, which leads me to believe that fermentation has stalled. The buckets still smell like wine, though not as strongly.

Is there any way to get this project back on track, or is this batch destined for the garbage? I searched the forum and found a similar thread, but no real solution, and ultimately the user's batch was thrown out. This is quite a bit of money worth of substrate (if it ever works), so I'm definitely interested in getting it going again if possible.

I gotta get this figured out, or substrate costs are going to break this hobby for me, and I want so badly for that to not happen.

 
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Same thing happened to mine, and I made a big batch too... I'm starting to worry that Traeger is treating their Oak pellets with some chemicals that retard the fermentation process...

I'd like to note though, that after several months of just letting it sit, fungus gnats turned it all to frass. So maybe it was edible, IDK... Didn't look or smell rotten though.

 
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Same thing happened to mine, and I made a big batch too... I'm starting to worry that Traeger is treating their Oak pellets with some chemicals that retard the fermentation process...
I was totally trolling on your post for an answer, but saw you didn't get it started again (or was it that yours never really got started to begin with?).

I actually just got off the phone with Traeger
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they were beyond helpful in looking up info for me. The rep said that the only ingredients in their oak pellets is oak wood and soybean oil (as a binding agent), and that the formula has been the same since they started producing. A quick search shows that soybean oil is used in certain types of fermentation, so I don't think it's inhibiting.

Last night I gave it all a thorough mix, poked some holes in the top, and left the lids sitting on top but not snapped down onto the bucket. I doubt anything is going to happen, but I have to hope.

Still open to any suggestions or advice.

 
I'm not an expert, that's for sure. There are many here that have many years of experience fermenting wood pellets. I only started about a year ago and I have done about 10 batches.

I can only share what I have experienced in these batches. Except for the first batch, all the other batches worked out and I have used them for my larvae so I assume it has worked.

The first batch I left outside and it was too cold at the time so it fizzled out. However, I refermented it and I was able to use it.

On the other batches, it was similar to what you are experiencing. The first 2 weeks, it had a pretty strong wine smell and gets warm, then it seems to do nothing but I believe it is still fermenting. You will notice that it gets darker.

After 4 weeks, I then repeat the fermenting process. The same thing occurs, first two weeks it gets warm and smells like wine, then it seems to do nothing. However, it will get even darker, almost black.

I then wait about 8 weeks and then test it on some larvae. I put half of the new substrate in a container with half old substrate. If the larvae start feeding on the new substrate, you are probably good to go.

I personally think the key is patience. Even though you don't continue to smell a strong wine smell or get a lot of heat, it's probably still working if the substrate is kept at 70 degrees and frequently mixed.

There are 3 things that you will notice when the substrate is ready. It's very dark, almost black or black. It has no strong smell, smells like a nice soil. When you pinch it, it's very soft with no sharp edges. It's almost like wet newspaper.

Some things that I find that helps the process is using wheat bran instead of flour and adding larvae frass. I know some guys who use frass instead of yeast.

So I think your substrate is doing just fine. Wait 2 more weeks and repeat the process. In 8 weeks after that, you will most likely have black gold.

Definitely don't throw it away just because it stalls! Even if it did completely stall (got too cold, etc), you can always repeat the process.

Good luck!

 
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I only started about a year ago and I have done about 10 batches.
10 batches is a lot of substrate, especially if you're counting a full 20lb bag of pellets as a single batch!

Mine is about a month in right now (2+ weeks since the heat died off), and if it has darkened it's barely enough to notice, though it may be hard to tell since I see it every day. I should've taken a before pic for reference.

It's very good to hear that you can repeat the fermentation process, though! I wasn't looking forward to throwing out 34lbs of potential substrate. I'm going to feed in some wheat bran and yeast this weekend. I actually saw a video about using frass last night, and I'm partially livid at the timing
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I just changed substrate for 4 of my L2s a few days ago, and there was so much frass that just got tossed out. Oh well; I know for next time.

Thank you for the info! One last question: I see conflicting info about using opened or closed containers (buckets in my case). How do you store yours, opened or closed? I've had mine closed until a couple nights ago and I've already got gnats appearing.

 
I do mine with vented lids. It's easier if you put them in containers that are flat rather than buckets. Churning buckets daily is exhausting. This happened to me before. However, I waited it out for 5 months and the substrate turned brown and smelled good enough to use. I produced minor-medium sized Dynastes hercules hercules and Dynastes tityus from it.

 
10 batches is a lot of substrate, especially if you're counting a full 20lb bag of pellets as a single batch!

Mine is about a month in right now (2+ weeks since the heat died off), and if it has darkened it's barely enough to notice, though it may be hard to tell since I see it every day. I should've taken a before pic for reference.

It's very good to hear that you can repeat the fermentation process, though! I wasn't looking forward to throwing out 34lbs of potential substrate. I'm going to feed in some wheat bran and yeast this weekend. I actually saw a video about using frass last night, and I'm partially livid at the timing
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I just changed substrate for 4 of my L2s a few days ago, and there was so much frass that just got tossed out. Oh well; I know for next time.

Thank you for the info! One last question: I see conflicting info about using opened or closed containers (buckets in my case). How do you store yours, opened or closed? I've had mine closed until a couple nights ago and I've already got gnats appearing.
The 10 batches were not full bags. Usually just half bags, sometimes just a third. Whenever I had some time, I make a partial batch. I just started using a composter and its much easier than mixing it by hand and you can do a lot more at one time.

As far as containers, I put the sub in clear bags that I have at work. They are about the size of a trash can bag. I cut holes in the bags for air and then tape weed cloth over the holes to prevent fungus gnats and the substrate from coming out. For me, it works great and its much easier to mix. You just toss the bag around a little, like making shake and bake chicken. No need to put on the gloves and dig through that darn bucket. I always thought mixing sub in a bucket was a total pain in the butt.

 
I do mine with vented lids. It's easier if you put them in containers that are flat rather than buckets. Churning buckets daily is exhausting.
I actually have an extra egg-laying tote I was thinking of using since this entire batch would fit in it. It's not so bad with just 3 buckets. I've only got them about 2/3 full each, so I can mix them without spilling or anything.

I just started using a composter and its much easier than mixing it by hand and you can do a lot more at one time.
When you say composter do you mean a tumbler, or like one of those rad electric kitchen composters that are readily available in Japan but totally aren't in the US unless you want to pay a high dollar-amount for a small capacity? I'm a bit salty about that if you can't tell
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I've been looking at tumblers a lot lately since I've read they cut down the composting time quite a bit, but it's still going to be way too cold outside to use one for a few months yet.

Thank you both for the feedback! I've noticed the fermentation smells are getting stronger in the room since I've been leaving the lids on but not snapped down so it can breathe, so I'm feeling better about the whole thing, and with your experiences with breathable/vented containers I think that's definitely the way to go.

EDIT/UPDATE: Bran and new yeast has been added. Not really noticing any heat being generated after 24hrs, but holy crap the stink is ungodly and strong. Like someone ran a 5k in leather boots with no socks on, then decided to try to kill the athlete's foot with crappy boxed wine.

 
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So the stink has subsided again, but there's a lingering warmth in all 3 buckets when I mix them.

The color of the substrate is definitely getting darker, although interestingly enough the bottom always seems to be very yellow compared to the top, which is a deeper brown each day. I also notice more of the sweet/sour scent when I pull the substrate up from the bottom to mix, whereas the buckets initially have that atrocious old shore/sock smell (albeit much lighter than before) when I first remove the lids.

I've continued leaving the lids on top, but not snapped down, due to a small gnat problem in my office/beetle room. This definitely seems to be doing better than fully snapping them down, though my wife is less than please about the smell in the room.

I've noticed that for about the last 4 or 5 days the entire top layer of the substrate sticks together like it's compacted (I make sure to leave it loose), and it's very spongy. If I were careful I'm sure I could remove the top inch or 2 in one piece like a substrate cake. This spongy/compacted texture also continues down along the sides of the bucket for a couple more inches. I'm not sure if this due to some sort of fungal growth. I haven't noticed any fruiting bodies or fuzz, but since I'm turning the substrate daily it may simply not have time to get to that point. If this is any cause for concern, I'd appreciate it if someone would let me know, but for now I'm just kind of noting it as an observation.

 
Just an update. I've moved all of the sub to a single 18 gallon plastic tote from Lowe's. There is consistent slight warmth in the middle of the sub when mixing, and the color is continuing to darken slowly, though the very bottom of the container is still always lighter than the top half (pics attached of before and after mixing). Hopefully in another month or two the substrate will be usable.

sub12918beforemix.jpg

sub12918aftermix.jpg

 
Still moving along (I think). This picture is after mixing. I no longer get the lighter color on the bottom of the container, and what little smell remains is earthy. I admittedly haven't been very diligent at mixing it the past week. There's not really any noticeable warmth anymore, and it's definitely not as dark as the oak flake I've gotten elsewhere, so I'm not sure if I need to re-ferment it or just leave it for a while longer. I'm definitely going to give it at least another month or so if the latter.

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How long has it been since the first fermentation and the 2nd one? As time goes on, you will see less and less heat, smell, etc. The changes start to become very slow. Also note that each type of wood and the company that makes the pellets will differ slightly in coloring. If you want to test some. Put some in a container and put half of your new stuff on one side and the old sub on the other side. See how your larvae react to the new stuff. Give them a few days. If they start hanging around in the new stuff, it's probably good to go! If they stay with the old stuff, it may need a little more time. From the picture, it looks really good.

 
I started the whole project on 11/18. Unfortunately, I didn't take not of when I added in the new bran and yeast, or if I did I've misplaced the note. I'm going to end up doing as you suggest and trying with a couple larvae before long, but I'm going to give it a couple more weeks first. The color difference between mine and the oak flake I've purchased is still very noticeable.

 
Heres some things I observed with the last batch of substrate I made. I noticed with the bucket method it takes way longer than it would with breathable bags. It also helps speed up the process if the water used to mix the pellets was an inoculate of previous substrate or organic garden soil. If I'm able to make a profit on selling the rest of my imports, I'm going to be buying a composter.

 
Well, it's been almost exactly 6 months, and I'm happy to say that the sub appears very close to being done. Once the temperatures started getting warmer I moved my sub container into my garage, and since it hadn't appeared to progress at all since my last picture post I mixed in a couple cups of wheat bran and another packet of yeast back in mid-march. It is definitely nice and dark now, almost the same color as BiC oak flake sub. I admittedly hadn't mixed it in over a week until yesterday, and there is a bit of a fecal odor at the bottom. It is definitely darker, though, so I'm going mix daily for a couple weeks and then try it on a larvae and see if they take to it. I had tried a small amount of it on a larvae back in February, and I found some frass at the top of the container where the new sub was, but not a lot, so I think that was just from the larvae exploring rather than consuming it.

And now that it's warming up some more I'm definitely wanting to do some outdoor batches in breathable bags (found suggested in other posts here), but I have some questions.

  1. What is the maximum ambient temperature for fermenting before you just kill off the microbes doing the work? I know if it's too cold fermentation doesn't work well, but what about too hot? My back patio regularly reads 115-120f during the summer.
  2. How do you control moisture when using those breathable bags? Do you just periodically spray them with a garden hose? It is extremely dry here (5% humidity today), and even kept in the shade I expect that the outside inch or more of the bags will absolutely dry out on a regular/quick basis.
  3. Is it best to start them off for the first month or two in plastic bins with daily mixes as I've been doing until the wine smell pretty much goes away and then transfer to the bags to let the sub mature?
I had really wanted to buy a compost tumbler, but with the new baby money has been even tighter than usual.

 
Great to hear!! Just a little patience was all that was needed. You were doing everything right
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I have to admit the first time I did the fermenting the thought of 6 months seem like eternity and that it shouldn't take that long. But when you see how dark it is and soft after 6 months, you realize that it was working and it does take that long. Of course, I still hate that it takes sooooo long!

 
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