[PDX Dopesmoker]

Originally Posted by Easy7

Anyone recall what processed food is like? Ya all get creative with processed ganja. That is a side effect of legalization, marketing, and boredom.

I enjoyed seeing your post closely followed by Patmando22's cold trap suggestion, but I got to tell you that some processed food is really good. Freeze-dried strawberries for instance have a fantastic flavor and a much higher density of that flavor than the original highly perishable fruit product. If you take freeze-dried strawberries and crush them while deeply frozen to dust in a food processor and then sift out the strawberry seeds the flavor density is even higher and you can use the pretty pink powder as very nice flavor additive for whatever you're cooking.
I grok your vibe and am down with it entirely, but sometimes the bored playboys come up with something genuinely worthwhile. The Wright brothers invented the airplane just fucking around looking for a new way to get high after all.

[ChaosCatalunya]

Originally Posted by WaterFarmFan

Thanks for the info. When you say "go quite strong", are you referring to a deep vacuum level? I am curious about vacuum level from my own vacuum oven terpene extraction experiments. Under deep vacuum, there is very little convection heating happening, because there are no gas molecules to bounce around and heat material. Thus, under vacuum there is only radiation and some conduction.

So, I wonder if they are doing deep vacuum during freeze process, which induces sublimation, and then a minimal vacuum level during heating process to encourage convection, which encourages evaporation? Is what I described the default state of the basic harvestright, or would it require programming?

Yes, I believe so, I will try to get some more info from my friend

[Lazyman]

Yeah the machine has an external vacuum pump attached. You can set how long to freeze and to vacuum.

It first freezes to -50*F for a few hours, which pushes the water out of the material as solid water ice. To get it to evaporate as a gas (sublimation) it applies a deep vacuum, then heats the trays up 10zF to -40*F, then freezes again and repeats for a day or two, or until no more water remains.

From what I've read about curing, chlorophyll only breaks down in conditions over 55% RH, and if it drops below that mark (too dry) the cure is "broken" and can't be restarted.

I'm still messing with my original jar, some of the smell is coming back a month later, but as I was looking at it as a possible commercial service endeavour, there's no hope yet.

Freeze drying leaves 0% moisture in the flowers, you could easily turn a handful of nugs into a fine dust with your bare hand.

You can add a cold trap, yes. I've seen videos of it being done, even homebrew in fashion, but it's probably far more economical to add the tiny amount of terpenes back by buying them. $600 for a cold trap would buy a shitload of terpenes.

[WaterFarmFan]

Thanks for that description. What happens to the water during the cycle?

[Patmando22]

It terns from a solid ice to a gas and gets vacuumed out without ever becoming a liquid

[bloyd]

Originally Posted by WaterFarmFan

Thanks for that description. What happens to the water during the cycle?

Most of the water vapor condenses and freezes to the inner metal drum which stays frozen at -50 f. You can defrost and drain this and your left with a hydrosol, I have tried to separate unsuccessfully with sep funnel. The water vapor that doesn't condenser on the drum goes to the pump oil. It is recommended to filter or change the oil after every dry session. You could put a cold trap in- line but the pump and dryer uses threaded 1 inch fittings so you need to custom make it I've never seen a commercial unit compatible.

The trays on my standard unit have silicone heat mats that are adjustable from 5°F to 150°F, I have tried various temperatures always below 125°F as low as 10°F in the end result is similar, so I think the intense vacuum is the main factor. You can also adjust drying time. I I believe the only difference with the scientific model is it gets a bit colder and can lead link to a computer.

In my mind I figured that it would preserve Terps very well being that the chamber stays at -50°F, but never thought about the fact that the activation energy required to sublimate water is greater than for terpenoids so obviously many of those will go before and with the water.

I could see its usefulness if you're drying pounds of bubble for a commercial market but currently I'm only using it to dry lady boys for pollen.

[WaterFarmFan]

Thanks Pat. This is where I am confused. I understand that sublimation happens at cold temperatures under vacuum, but the water vapor still behaves as a gas once it leaves plant material, which makes me believe that it will condense back to liquid/frozen ice on the coldest parts of the freeze drier. If this is happening, then terpenes are also condensing on the chiller element of the freeze drier. If not, then large amounts of water with some terpenes would be constantly contaminating vacuum pump oil?

EDIT - Thanks Bloyd. Answered a lot of my questions.

[Patmando22]

You are right, there is a part in the freezer that gets iced up i think. That would be were most of the lost terps would be. I think it would be hard to recover them from the ice.

[Patmando22]

Im sure you loose terps in a traditional dry of water hash. The difference between the amount of terps lost from the different drying methods is what im most interested in.

[WaterFarmFan]

Does the chilling element ever turn off during the heating cycle? Does the vacuum pump stay on during the entire cycle?