Building an inexpensive incubation chamber

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Also see:  Wheat Straw Tek
Incubation Chamber Assembly


Directly after the freshly prepared jars of substrate have been inoculated, the jars are then stored in incubation during the initial colonization phase.

Correct incubation consists of keeping the jars at a constant substrate temperature value of 86' f. The average time required for this initial growth phase to be completed is about 10-20 days. (see chart below for a representation of how temperature value directly affects the growth rate during the vegetative growth cycle)

There are many ways to build an incubation chamber that is capable of accomodating the initial incubation phase, but the one offered below is one of the most easiest and effective for the price and works very well for the job.

One of the most important aspects to consider when setting up an incubation chamber is the way in which it heats the substrate. Dry heat sources (such as heating pads) obtain their increase in temperature by robbing the surrounding
area of its moisture. This is very dangerous to the colonizing jars of substrate because this form of heat can easily dry up the moisture that is available in the substrate jars before the mycelium has had the chance to fully colonize it.

Radiant heat sources will not rob heat from the jars of substrate and are therefore a superior means of providing heat to the incubation chamber.

Items needed:

Styrofoam cooler ($2-$6)
50w Aquarium heater ($10)
Thermometer gauge ($2-$15)
A large glass fruit jar


Simply fill the large glass jug with water:

A cap full of h202 can be added:

Add the heater to the jug:

Place the jug in the Styrofoam cooler:

Adjust the timer so that it maintains a temperature range of 84�f. The substrate temperature is usually a couple of degrees warmer than the surrounding air temperature. If you are using a thermometer that has a probe for outdoor temp reading, then you should place the probe between two jars of grain so you can get an idea of the substrate temperature as well as the inside air temp. (see pic below for reference)

Once the heater is set to the correct setting, it will trickle on occasionally, as needed, to maintain the proper temperature.

During the incubation phase, if you intend to case later, the jars should be kept in complete darkness. A very limited exposure to light is acceptable when checking on growth, but the jars should never be left out exposed to light for any considerable length of time, unless you plan to grow invitro or from uncased cakes.

That's it! Radiant heating doesn't come much easier than this.

Here is something worth mentioning for those of you who may be having trouble figuring out how to get the aquarium heater temperature above the stock setting:

*Note: The aquarium heaters are set to a default setting that will only allow the element to heat up to 75-6'F. In order to make one work, you have to read the instructions that came with the heater. It explains how you must lift the dial setting knob off of the unit and rotate the exposed rod or shaft thing around and then replace the plastic knob back on to the dial. This will allow you to raise the temp to the desired setting, although it may take a few adjustments to get it set at the ideal temp range.

By Roc (Rochester) on Saturday, January 05, 2002 - 08:39 am: The Nook

I found that if my jars are up off the bottom say 4-5" this setup works better. Heat rises in the styro container and you'll see 5-10 degree diff...
just my 2cents.

By nuecrew (Nue) on Monday, January 07, 2002 - 03:06 pm: The Nook

Nice! You are a friend of the DIY'er. Love your energy Quote.

By Dr. Cubesis III (Newbieshroomer) on Monday, January 07, 2002 - 05:40 pm: The Nook

In my buddies large ( freezer ) fruiting chamber, even with the
humidifier piped in and on, he maintains a temperature of 75 degrees without any heat source.
This is one of the reasons he wants to grow in-vitro, temp is already perfect :)

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