Wet seed processing - small/medium scale
Posted: Wed May 03, 2023 2:24 pm
This is a description of our wet seed processing method that we have developed for Avoca Seed. It isn't perfect, or maybe even the best way, but it works very well for us, and I thought I would share it here. This is the first place I have shared the details of this method outside our farm. I will try to find some pictures and post them soon.
We use this processing method for a variety of wet seeded crops including peppers, eggplants, tomatillos. It works effectively for 0.5 lb to about 40 lb seedlots. We developed this method over many years with peppers initially. It consistently results in high germing, clean seed. It uses some specialty equipment, like the chipper, but everything is usable for many things in many ways. The whole equipment expense of this should be under about $400. With two people and two wheelbarrow setups, we can process up to about 15 lbs of seed in a day, including setup and cleanup. It takes a little finesse, a little setup and cleanup, it's very scaleable, and it's much cheaper than the wet pepper seed processing machines you can buy that only do one thing.
Supplies:
Rotohoe Chip-N-Shred chipper.
Works best with the chipper blades replaced for duller, flail-like grain threshers, as described in this article:
http://www.theruminant.ca/blog/2013/01/ ... n-thresher
Ours has an electric motor. It is an amazingly versatile tool for small-medium scale seed processing. We use it a lot for dry and wet seeds, we found ours used for about $125 and added a custom electric motor, total expense about $250. I see Rotohoes commonly for sale locally. I'm not sure if they are widely available in other areas, or if other types of chippers would also work. If you don't have a Rotohoe, you can use rubber boots and a large tote to stomp the fruits in.
Several totes about any size in the 14-18 gal range. Specifically, a 14-gal rubbermaid tote fits perfectly under the chipper. (I'm pretty sure Rubbermaid totes can be purchased at any Ace hardware store, sometimes we've have to special order them from our local hardware store that is under the Ace umbrella.)
Some small pieces of plywood cut to sizes to appropriately fill gaps in the chipper
A wheelbarrow, or two.
A scoop or small bucket of some kind, that holds about a gallon or two.
Hose with average water pressure
Ear protection
Eye protection, mask, and rubber gloves if you're doing hot peppers!
QTJH Collapsible Storage Bin
https://www.amazon.com/QTJH-Collapsible ... 8T4F6?th=1
(I found these for our farm in the 2022 season. They are amazing. The screen size is just right for a wide variety of seeds - for a coarse field screen to quickly get the chaff out. I don't like plastic, but these are very durable and hopefully will last a long time. They have very few nooks and crannies for seeds to hide in, making for easy cleanout.)
15.75" DEEP PROP FLAT
https://growers-inc.com/15-75-deep-prop-flat-20-cs/
This is from our local nursery supply place, but you can find them anywhere. Another very useful, durable, versatile screen. (These nursery people are using them for the wrong thing, and they don't even know! Ha.)
Setup:
Position the chipper near water and power (if using electric motor). Careful with motors and extension cords. Too long or light duty of a power cord can melt and be a fire hazard. I think we have a 1/4 hp motor and the most we can have is a 25', 12-gauge extension cord. There are calculations you can do about the amperage, wire gauge, and maximum distance of your specific motor and situation.
A 14-gal rubbermaid tote fits under the chipper, from the front to catch the seeds. You have to wedge it a bit. Cut a piece of plywood and wedge that in the back/underside to direct seeds into the tote. Put another piece of plywood on top of the chipper to partially cover the hopper. This prevents seeds from flying out the top. Cover the side chute of the chipper with something. I cut a bucket lid with my pocket knife and wedged it in.
Position a tarp for the wheelbarrows to sit on. This is not strictly necessary, but can reduce mud and can be a safety net in case of a seed spill.
Position the wheelbarrow a few feet away, with the QTJH bin in the wheelbarrow. Fill the wheelbarrow about 1/3 full of water. The top edge of the QTJH bin should be about 1-3" out of the water while sitting on the bottom of the wheelbarrow.
Position a tractor bucket, or whatever you are going to use to move the pepper flesh without the seed, to somewhere else, like the compost pile.
Process:
Pick the peppers color ripe, as you see fit. Bring them to the chipper.
Turn on the chipper, pour the peppers into the hopper slowly.
When the rubbermaid tote is mostly full, turn off the chipper. Remove the tote and scoop 1-2 gallons of "oosh" into the QTJH bin in the wheelbarrow. Agitate gently, moving the screen around partially submerged in the water. This is the tricky part. The good seed sinks and most of the pulp/flesh floats, and is contained by the QTJH bin. After a short agitation, remove the QTJH bin quickly up and out of the water. Any remaining seed will be pulled down with the water by this action. Dump the seedless oosh in the tractor bucket. Add some water to the wheelbarrow. Repeat 3-4 times, each time adding a little more water. Adding water helps the dilute the sugars in the water and keeps the specific gravity of the solution low enough so that the seed sinks. This is specific gravity as in the beer brewing sense. If the specific gravity gets too high because there is too much oosh and juice in the water, this will cause some seeds to not sink.
After 3-4 repeats, set the QTJH bin aside. It is time to pour off the water, and find the gold in the bottom of the wheelbarrow. For the first time, it might be a good idea to pour the wheelbarrow onto a 1/8" hardware cloth screen, just in case of any accidents. After you get the hang of it, you won't need this. Position yourself firmly and pour the water out of the wheelbarrow slowly. Breathe and trust. The seed is being "decanted". Some seed will always float away. The good seed sinks. Transfer the seed from the wheelbarrow to a tote and set aside. Repeat the whole process until you're through with all the peppers.
Return to the tote with the seed in it. Screen it one more time in a similar wheelbarrow process, using the Prop Flat. This has smaller holes that catch a little bit more pulp while allowing all the seed to go through.
Return the seed to the tote. It is time for the final decanting process. Carefully spray some water from a hose in a swirling motion, creating a vortex. The lighter seed and pulp will come to the top. Remove the hose and set aside. With the swirl still going, tip the bin slowly towards one corner. Breathe and trust. Pour out water and pulp and some floating seed until you see sinker seed about to come out. Stop! Refill the bin in the same way with the hose. Repeat several times until you think it's clean enough.
Spread out on a screen to dry. You're done!
Clean out the chipper thoroughly with the hose. Open the top, spray out from all sides, and underneath. We put a dry bin over the motor so it doesn't get wet.
This exact method works great with peppers, eggplant, and tomatillo. Tomatillos tend to clog a bit because of their husks. Eggplants are loud, but work just fine for us.
If you don't have a chipper, you can substitute stomping on the fruits with rubber boots in a rubbermaid style bin with a little water in it. Then proceed with the wheelbarrow. This works for peppers and tomatillos, but eggplants may be too firm to stomp. This stomping method is perhaps preferable for very hot peppers because it doesn't spray pepper juice everywhere like the chipper does.
Best of luck! If anyone has questions, I'll try to answer them.
Hank
We use this processing method for a variety of wet seeded crops including peppers, eggplants, tomatillos. It works effectively for 0.5 lb to about 40 lb seedlots. We developed this method over many years with peppers initially. It consistently results in high germing, clean seed. It uses some specialty equipment, like the chipper, but everything is usable for many things in many ways. The whole equipment expense of this should be under about $400. With two people and two wheelbarrow setups, we can process up to about 15 lbs of seed in a day, including setup and cleanup. It takes a little finesse, a little setup and cleanup, it's very scaleable, and it's much cheaper than the wet pepper seed processing machines you can buy that only do one thing.
Supplies:
Rotohoe Chip-N-Shred chipper.
Works best with the chipper blades replaced for duller, flail-like grain threshers, as described in this article:
http://www.theruminant.ca/blog/2013/01/ ... n-thresher
Ours has an electric motor. It is an amazingly versatile tool for small-medium scale seed processing. We use it a lot for dry and wet seeds, we found ours used for about $125 and added a custom electric motor, total expense about $250. I see Rotohoes commonly for sale locally. I'm not sure if they are widely available in other areas, or if other types of chippers would also work. If you don't have a Rotohoe, you can use rubber boots and a large tote to stomp the fruits in.
Several totes about any size in the 14-18 gal range. Specifically, a 14-gal rubbermaid tote fits perfectly under the chipper. (I'm pretty sure Rubbermaid totes can be purchased at any Ace hardware store, sometimes we've have to special order them from our local hardware store that is under the Ace umbrella.)
Some small pieces of plywood cut to sizes to appropriately fill gaps in the chipper
A wheelbarrow, or two.
A scoop or small bucket of some kind, that holds about a gallon or two.
Hose with average water pressure
Ear protection
Eye protection, mask, and rubber gloves if you're doing hot peppers!
QTJH Collapsible Storage Bin
https://www.amazon.com/QTJH-Collapsible ... 8T4F6?th=1
(I found these for our farm in the 2022 season. They are amazing. The screen size is just right for a wide variety of seeds - for a coarse field screen to quickly get the chaff out. I don't like plastic, but these are very durable and hopefully will last a long time. They have very few nooks and crannies for seeds to hide in, making for easy cleanout.)
15.75" DEEP PROP FLAT
https://growers-inc.com/15-75-deep-prop-flat-20-cs/
This is from our local nursery supply place, but you can find them anywhere. Another very useful, durable, versatile screen. (These nursery people are using them for the wrong thing, and they don't even know! Ha.)
Setup:
Position the chipper near water and power (if using electric motor). Careful with motors and extension cords. Too long or light duty of a power cord can melt and be a fire hazard. I think we have a 1/4 hp motor and the most we can have is a 25', 12-gauge extension cord. There are calculations you can do about the amperage, wire gauge, and maximum distance of your specific motor and situation.
A 14-gal rubbermaid tote fits under the chipper, from the front to catch the seeds. You have to wedge it a bit. Cut a piece of plywood and wedge that in the back/underside to direct seeds into the tote. Put another piece of plywood on top of the chipper to partially cover the hopper. This prevents seeds from flying out the top. Cover the side chute of the chipper with something. I cut a bucket lid with my pocket knife and wedged it in.
Position a tarp for the wheelbarrows to sit on. This is not strictly necessary, but can reduce mud and can be a safety net in case of a seed spill.
Position the wheelbarrow a few feet away, with the QTJH bin in the wheelbarrow. Fill the wheelbarrow about 1/3 full of water. The top edge of the QTJH bin should be about 1-3" out of the water while sitting on the bottom of the wheelbarrow.
Position a tractor bucket, or whatever you are going to use to move the pepper flesh without the seed, to somewhere else, like the compost pile.
Process:
Pick the peppers color ripe, as you see fit. Bring them to the chipper.
Turn on the chipper, pour the peppers into the hopper slowly.
When the rubbermaid tote is mostly full, turn off the chipper. Remove the tote and scoop 1-2 gallons of "oosh" into the QTJH bin in the wheelbarrow. Agitate gently, moving the screen around partially submerged in the water. This is the tricky part. The good seed sinks and most of the pulp/flesh floats, and is contained by the QTJH bin. After a short agitation, remove the QTJH bin quickly up and out of the water. Any remaining seed will be pulled down with the water by this action. Dump the seedless oosh in the tractor bucket. Add some water to the wheelbarrow. Repeat 3-4 times, each time adding a little more water. Adding water helps the dilute the sugars in the water and keeps the specific gravity of the solution low enough so that the seed sinks. This is specific gravity as in the beer brewing sense. If the specific gravity gets too high because there is too much oosh and juice in the water, this will cause some seeds to not sink.
After 3-4 repeats, set the QTJH bin aside. It is time to pour off the water, and find the gold in the bottom of the wheelbarrow. For the first time, it might be a good idea to pour the wheelbarrow onto a 1/8" hardware cloth screen, just in case of any accidents. After you get the hang of it, you won't need this. Position yourself firmly and pour the water out of the wheelbarrow slowly. Breathe and trust. The seed is being "decanted". Some seed will always float away. The good seed sinks. Transfer the seed from the wheelbarrow to a tote and set aside. Repeat the whole process until you're through with all the peppers.
Return to the tote with the seed in it. Screen it one more time in a similar wheelbarrow process, using the Prop Flat. This has smaller holes that catch a little bit more pulp while allowing all the seed to go through.
Return the seed to the tote. It is time for the final decanting process. Carefully spray some water from a hose in a swirling motion, creating a vortex. The lighter seed and pulp will come to the top. Remove the hose and set aside. With the swirl still going, tip the bin slowly towards one corner. Breathe and trust. Pour out water and pulp and some floating seed until you see sinker seed about to come out. Stop! Refill the bin in the same way with the hose. Repeat several times until you think it's clean enough.
Spread out on a screen to dry. You're done!
Clean out the chipper thoroughly with the hose. Open the top, spray out from all sides, and underneath. We put a dry bin over the motor so it doesn't get wet.
This exact method works great with peppers, eggplant, and tomatillo. Tomatillos tend to clog a bit because of their husks. Eggplants are loud, but work just fine for us.
If you don't have a chipper, you can substitute stomping on the fruits with rubber boots in a rubbermaid style bin with a little water in it. Then proceed with the wheelbarrow. This works for peppers and tomatillos, but eggplants may be too firm to stomp. This stomping method is perhaps preferable for very hot peppers because it doesn't spray pepper juice everywhere like the chipper does.
Best of luck! If anyone has questions, I'll try to answer them.
Hank