Re-using unburnt fuel

[AlanL]

I tried my 3rd smoke on my 47 WSM last weekend and although the first two went pretty well I struggled with maintaining a high enough temp this time round. The first cooks I used plenty of fresh Briquettes (Weber long burn - white bag) as better to have more fuel than not enough. After each of those cooks I closed down the vents and next day saved any unburnt fuel. So this weekend I had a fair amount of saved briquettes that thought I'd use. I put 1/2 chimney of fresh fuel on grate slightly more than about 2/3 chimney of used fuel on top and then 1/2 chimney of lit fuel on top of that. In total similar volumes to previous cooks. Even with all vents open I couldn't get temp above 105 according to the lid gauge an for first two hours was typically closer to 95-100. Previous smokes I had no problem staying within the 115 to 125 range and would have to tweak vents (usually set @ 1/2). In order to try and get temps up I lit a 1/2 chimney and got them well lit and carefully added. Briefly (under and hour) I got the temps up to 115 but after that fell back to 100. I then just let it cook at that temp and waited until meat was cooked. Tested with thermometer to confirm all was OK. I should say that the water pan was pretty full and same level I started previous cooks with. Thinking back maybe I should have siphoned some water out.

As the day was not particularly cold or windy, similar in fact to the other days, so the only real difference was the use of the reused fuel.

Do others reuse unburnt fuel? If so do they make any allowances doing so? Would it have been better if I'd used this as the starter fuel in the chimney at the offset?

It might be something to do with the Weber fuel so plan to try Heat Beads next time.

If it's not going to be a good idea to reuse fuel then I need to be more precise on my initial set up to save waste. A 10KG has done 3 smokes of around the 7 hour time so does that sound like I'm using too much fuel in the first place?

[ConorD]

What fuel were you using (brand) as I use heat beads and always start my new cook with whatever was left from a previous go. Sometimes there is only enough for the starter chimney but often it is a 50/50 mix in the basket of new and old. I have not done an entire basket of old but have never had a problem with the mix.

[LetItSmoke]

well, a 15 degree sacrafice when using old fuel is actually oretty good. It goes without saying that, as the fuel is partially burnt, the fuel's optimum temperature can't be reached. You could, however, acheive a higher temperature by leaving the vents open during the cook, and using twice as much fuel, as a thicker layer brings higher temperatures. Also, if you have an adjustable grate/grill, posistion it as close as possible to the fuel, so as much heat as possible reaches the cooking food.

[Clayfish]

I use lumpwood charcoal and always reuse the unburnt stuff. I usually use it in the starter chimney so by the time its alight it makes no difference, also it means the charcoal I dump it on is usually fresh.

[LetItSmoke]

Oh, and you are right. Heat Beads will definitely give much greater performance than Weber.