Harvest & Curing Drying in the cold

[Badgersbunk]

I wasn’t thinking of where I’d be drying over the winter when I decided on a perpetual grow. I usually dry in a dry box I made in my garage because I can’t have smells in my house. With winter here I’m wondering how bad it is to dry in the cold. Temps are 35-50’F currently and dropping . I’m sure it’ll take longer to dry but am I asking for trouble.

 

[JSH1973]

I would imagine that you would up the airflow a bit to avoid mould and it would take a good bit longer, Interesting question for sure.

 

[Badgersbunk]

I would imagine that you would up the airflow a bit to avoid mould and it would take a good bit longer, Interesting question for sure.

That’s kind of what I was thinking, As long as It stays above freezing till I’m done.

 

[Eyes on Fire]

I dry when its cold and dry out.But usually not below 45-50F at lowest I have done.It works fine but lower...Uncertain how that'll go.usually around 55-60F and low RH ad its doe in 3-5 days depending on a few things but its awesome.ad a small breeze is barely all you need just to push a small bit of air aroud.lol

 

[Badgersbunk]

I’m doing a test today to see how well the box retains the heat from me working out there. The box is osb with an vari-speed fan on top sucking out the box and the intake holes are on bottom with furnace filters over em. It works real nice in summer keeping temps low. I’m out there most the day with a propane heater so I’ll just need to see how far it drops according to night temp.

 

[Olderfart]

I’m doing a test today to see how well the box retains the heat from me working out there. The box is osb with an vari-speed fan on top sucking out the box and the intake holes are on bottom with furnace filters over em. It works real nice in summer keeping temps low. I’m out there most the day with a propane heater so I’ll just need to see how far it drops according to night temp.

I haven't dried at those temps, but I think you will need to keep an eye on relative humidity. Your propane heater sounds potentially risky to me. Unless the heater exhausts the combustion gas outside the garage, it will be adding a lot of water to the air in there, potentially elevating your RH lots. The change to lower temperature overnight could also raise RH significantly compared to daytime levels. Do you have a thermohygrometer that can measure your RH? Some of them can show min max levels as well, which could be instructive re. your overnight RH.

 

[Mañ'O'Green]

Your crop may actually dry faster in those conditions. what is most important is you do not hit or get too close to the dew point. This is where condensation can form in the buds - a very bad thing.

Here is a helpful calculator:

Dew Point Calculator

Dew Point Calculator is a web resource created by the Image Permanence Institute to help express and visualize the relationship between temperature, relative humidity and dew point.

www.dpcalc.org

It is designed for artwork but shows the relationship between temperature, RH and Dew Point:

 

[Badgersbunk]

Dew point is something I didn’t think about, and after thinking harder the change in temp outside the box could probably cause some condensation inside.

 

[Mañ'O'Green]

Dew point is something I didn’t think about, and after thinking harder the change in temp outside the box could probably cause some condensation inside.

Just like in a green house it is ok for condensation to form on the inside wall as long as the temperature inside is warmer than outside. It is actually drying the air inside. If it goes the other way colder inside than out you will have troubles.

 

[Badgersbunk]

I’ll be monitoring the temp and rh inside the box over the next few days to see how it behaves with temp outside. Thinking maybe an incandescent bulb under the box for heat but all light is blocked from entering box. That’s what I use in dead of winter to keep my ice fishing minnow tank from freezing. I’ve still got 2 weeks before harvest so I’ll be experimenting.