Cold Smoking Troubleshooting Guide
Like all precision pieces of equipment, and the Pro Q Cold Smoke Generator (CSG) being no different requires cleaning to keep it performing effectively.
Cleaning the CSG with a toothbrush or fine wire brush will remove burnt dust particles and loose carbon deposits which have collected on the mesh during burning. However a more thorough clean of the CSG should be performed on a regular basis to remove the baked on carbon that is blocking up the fine wire mesh of the CSG, therefore preventing air (oxygen) which allows the dust to burn effectively.
I have found that by spraying the Cold Smoke Generator with oven cleaner every couple of uses helps to dissolve and remove the build up of carbon that can block the fine mesh on the walls of the CSG. This will allow better air flow through the fine mesh walls of the CSG and keep the CSG performing as new.
Occasionally we receive messages from customers, and also read articles on social media where someone is having problems either lighting their dust, or not managing to keep the dust alight for the full amount of time, and more often than not the dust is blamed for being too damp. Video's 1 & 2).
At Smokewood Shack during every batch of dust we make we take moisture readings to ensure the dust falls within our parameters, in addition we also complete a test burn to ensure that the dust burns correctly.
Throughout thousands of hours test burning since we have been manufacturing our own dust we have found that the following can make a difference:
1. If there is a build up of smoke, and therefore not enough air passing over the dust this can starve oxygen getting to the dust. To rectify this, either keep all your vents open , or ensure that the top and bottom vents are fully open to allow maximum air flow through the bottom vent, over the CSG and through the cooking chamber and finally allowing the smoke to exit.
2. Baking the dust in the oven will reduce the moisture level of the dust but there is no need as the moisture level of the dust is already dry enough to start with. By completely drying out the dust you are effectively destroying all the natural sugars and flavours so you will not fully benefit the great flavours that the wood naturally produces.
3. Drying dust in the microwave has an initial reverse effect on the dust. We have found through tests that by microwaving the dust this will produce excessive steam and create additional moisture within the dust, this will increase the moisture level of the dust by up to 90% until the dust fully cools down and the steam has fully evaporated. Our experiments have shown that by microwaving the dust and waiting for the dust to cool down you will only lower the moisture level by 1 or 2%.
4. Through experience I have found that if the dust burns for a while and then goes out after burning for a short period of time the small mesh holes of the cold smoke generator may be blocked with carbon therefore starving the dust of oxygen. (Video 3). If the dust was burning OK, and then went out, something has changed for it to go out. You have selected the dust randomly from a bag which has been added to the Cold Smoke Generator, so what has changed ? It can't be the dust as it was burning fine previously!
Going back to basic fire making, you need a fuel source (the dust), an ignition source (the candle), and an oxygen supply to the fuel source to maintain combustion, if you emit one of the above you will not be able to light your dust, or the dust will stop burning.
5. In most cases if the dust goes out straight away it is because the dust has not been lit in the first place. I have found that keeping the candle lit and in place for around 10-15 minutes , or until the lit dust has travelled about 2.5 - 3 cm's, therefore proving that the dust can remain lit and burn without the aid of the candle flame.
6. We have also discovered on a few rare occasions out of the many test burns that we conduct if the tea light candle has been used previously for prolonged periods of time the flame is not long enough to effectively produce enough heat to ignite the dust. Definately worth keeping an eye on to avoid frustration!
7. A couple of years ago we conducted a study of seven of the most popular dusts, Apple, Beech, Cherry, Hickory, Maple, Oak, and Whisky Oak. All the dusts had different moisture levels ranging from 7% (which is the moisture level of the average internal house door) up to 23 % which is a very high and excessive moisture content for dust. Each species of dust completed the burn cycle. The average moisture content of all our dust is approximately 10%.
7. We have repeated the experiment and have filmed the results:
Photo's 1 & 2 accompany the first video (parts 1 & 2). Unfortunately the battery ran out of power therefore we had to film the video in 2 parts. We used Oak dust as it is the most popular. The first photo is the actual moisture level of the dust (8.1%), the second photo is after we have sprayed the dust with water (26.1%), and the moisture level is a lot higher than you would normally find.
Photos 3 & 4 accompany the second video. We used Maple dust for the second experiment. The first photo is the actual moisture level of the dust (7%), the second photo is after we have sprayed the dust with water (27%), and the moisture level is slightly higher than the first video.
The third video we used Maple again, but in this video we created a build up of carbon at a specific area of the CSG, which effectively starved the dust of oxygen, therefore the dust would not maintain combustion.
I am sure there are other reasons why the dust might not burn correctly, for example high winds causing issues with air flow or a build up of gases etc therefore starving the dust of oxygen. but unfortunately I do not have the facilities or correct equipment to accurately measure these things. I have only measured the moisture content of the dust using a moisture meter and also interrupting the air flow getting to the dust, therefore concluding that a moisture level up to 27% will maintain combustion and the dust will burn effectively. However by creating a build up of residue on the Cold Smoke Generator this will restrict air flow getting to the dust and will effectively starve the dust of oxygen.