Sometimes, the supply of fresh foods for black soldier fly larvae may not be as steady as we want. Maybe the food spoils before the BSF have a chance to munch on them. A way to solve this is to make longer-lasting food that is both odor-free & nutritional for the baby larvae. Let's have some fun checking out the fermenting method and let's see right below:
Fermenting the Foods
Fermenting the foods for the larvae extends the storage time for up to 3-6 months. This means we can store the foods for a long period of time without worrying about mold/houseflies or foul smell.
Perhaps in a year, we only need to prepare the foods twice. When fermented, it will give off a slight acidic smell that's totally bearable & doesn't stink. This method is suitable for farms or someone who raise BSF indoors near residential areas.
The recipe we'll use today is:
- 40 gram EM/ lactic acid bacteria /bread yeast
- 1 kg wheat bran/rice bran
- 80 kg yam/potato/soybean waste/cassava tuber
- 200 gram sugar/molasses
- 40 liters of water
If you'd like to see how to make your own EM or lactic acid bacteria easily at home, check out this post later:
>> Blog post: How to make EM1 effective microorganism (3 secret recipes)
Why Add Yeast?
To ferment 80 kg food waste, we'll have the yeast/fermentor or EM. You can use pre-made packages or make your own. These are the little microbes that get the work done fore us. Those that work best for this are Lactobacillus, Bacillus, Streptomyces, Saccharomyces.
Basically, these are our little mighty warriors. Once they are released into the food waste, they'll do much of the heavy-lifting for us–chewing the food, breaking it down into smaller pieces & reducing the smelly smell for us. Thus, also making the foods last longer in the acidic environment that they've created.
What Is the Wheat Bran For?
Wheat bran, rice bran or rice water really helps in activating these guys. Anything with a good amount of starch will do. The sugar or molasses will be the food for the microbes & helps keep the fermentation process going. If you can't find molasses around your area, sugar cane juice or other types of sugar is also fine.
Mixing the Foods
In a 120-liter bucket (or 55 gallon drum), mix in these components. You can use a heavy-duty electric mixer to save time & effort. Once the mixing is done, place the bucket in a cool, shaded area with a lid on top.
In the first week, remember to open the lid slightly to let off some CO2 gas, a by-product of this fermentation. Then, you can let it sit there & take out some food for the BSF larvae anytime you see fit.
Using the Foods
Some people use the foods when it's about 10 days old. You can let it soak for longer. You may see some white film or fuzz at the top surface & this is completely normal. It won't harm the food source. In simple words, this is like pickles. When you like it, you can take it out for consumption. The foods won't spoil if kept in these conditions.
Making BSF Food Last Longer
The benefit of making the fermented food for BSF larvae is the acidic environment it creates. This acidity makes it nearly impossible for other life forms to survive, except for the very hardy good microbes. The foul smell will also be reduced.
Houseflies, the main cause of your loved ones saying 'Oh it stinks, get it out of the house please', won't be buzzing around anymore. Best of all, the foods will retain most of their nutritional value, they can be kept for longer & will be easier to digest for the larvae.
Have fun exploring & share with us some tips you have. Enjoy! But one last note, don't turn them drunk by alcoholic fermentation. :) But it's your call after all.
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Hi,
That’s very informative, Can I use other organic waste cabbage and other vegetables except for potato or yem?
@Anonymous , Hi, thanks for the kind words. I believe you could substitute the potato or yem with other veggies. The purpose of it is to provide some starch for energy for the larvae. You could put this into consideration when mixing the food for a more balanced nutritional profile (fruits / veggies / starch) for the larvae. I hope this helps!
Hello, i am about to start bsfl on a massive scale therefore i need your assistance to make sure i don’t mess up the fermentation process. Please get back to me whenever you get time.
Thankyou,
Regards
@Qasim , Hi Qasim, thank you for your message. It’s Hien. We’ve contacted you via email.
If I can get waste from beer making from a micro brewery this should already be fermented. How long will this last? Can have 1000 pounds of this if I need it, but I don’t know how long it would keep? Does it have to be refrigerated ? Or just let it keep fermenting. Do you think it could last 6 months in buckets or drums? I want to scale up to provide more for the chickens and others animals and fish on the farm. Right now I have a 55 gallon drum and Its loaded with BSF larvae. Have enough for 30 chickens for snacks 3 times a day and feeding a rescued possum with them now. I live in a humid and hot climate and they are naturally here. Need advice of the micro brewery mash please…
@Dede , Hi, thanks for your questions. If you decide to get the brewery waste as feed, make sure to get fresh one to begin with as old ones could gather contamination on them. Once you receive it, you can let the waste sit to cool down but not usually more than 2-3 days as it could develop a foul smell. Then you can dump the waste in drums for storage.
From an experienced grower that I asked (Martin Tenywa from Ento Organic Farm), usually, in an air-tight condition and free from fly-egg oviposition, brewery mash in drums can last for up to 3 months. People add about 2-3% molasses and 0.5% salt by weight to make it keep longer.
Since you’re in a hot climate, you could find a shaded corner in the farm to place the drums. This is so the fermentation doesn’t happen too fast (to keep the feed in sync with how much/how fast the chickens consume it on a day). Some recommend pressing the waste down to squeeze out more air. And remember also to put the lid on tight. Some people also get fermentation powder (yeast, bacteria that’s going to digest the food) and mix in with the mash. From their epxerience, with the powder mixed in, the waste can be good for 2 weeks to a month. When you open the lid to scoop some out, you may find that the feed still has a nice bearable smell.
Additionally for feeding, you could mix in some concentrated vitamin powder. But only within 24hrs before feeding and not mixing the vitamin powder together while fermenting in drums, as the microbes could eat up all the good vits. For milk cows, you don’t want to feed it more than 33lbs of beer waste/per cow/per day. Because it will decrease the digestion rate of fiber and other nitrogen-containing substance, thus decreasing the quality of the milk.
Alternatively, you could check out silage (also known as pickled pasture). Brewery waste is a great component for making silage. You can keep it for 6 months or more to feed the black soldier flies
I hope this helps!
@Hien , @Hien Will that hurt the larvae?
@Mil , I believe they’ll be fine. If I recall correctly, some fermented cabbage and carrot (slightly sour) that I threw in disappeared the next day.
Great article!
What are your thoughts on using fruit (ie apples) instead of potatoes and omitting the sugar?
Would this lead to it turning into alcohol? Is there any way to prevent that from happening?
The reason I ask is that there’s a large apple tree in my SO’s backyard and they have more apples than they know what to do with.
Hi Di, thanks for your comment! In response to your questions:
Fruit is a great choice to begin with if you can find plenty for cheap & don’t want to deal with foul smell from meat or bones. I’ve seen people use seasonal fruits like unsold watermelon (on a large scale) and dragon fruits for feeding. Just a note on citrus & avocado though if you happen to find some. They do eat the flesh of citrus fruits, not the rinds because of the terpene stuff. Avocado pits and rinds, not so much, but the flesh is good.
Depending on how sugary/tart the apples are, you may add more or less sugar or none at all. The point of the sugar or some salt minerals is to give some food for the little microbes, which will do the work for us to make the food last longer. So if there’s already some natural sugar in the apples, I think it’ll be fine.
To make it not turn too alcoholic, use less sugar and keep your mix in a cool dark place. I’d say below 80-89F (27-32C) is good. For example for 1 apple - you can put 1 tsp or 4 grams of sugar (this is also similar to the apple cider vinegar recipe). Even if the mix is slightly acidic or vinegar, the BSF can handle it. They got some pH buffering going on in their guts.
Go for it! Would be interesting to know the results.
I hope this helps!