Is a smoker water bath really essential?… No, it’s not, but in most circumstances it really does help control temperature and keep food moist so if in doubt I would always include it.
What Is A Water Bath?
Some smokers will come with a water bath already provided but it's nothing complicated, simply a roasting tray that you put under the grate upon which you are going to smoke the meat. A disposable foil tray works just as well.
When hot smoking food, other than the passing of smoke through the food chamber, there are three other things to consider:
Whilst the humidity doesn't need to be "controlled" it is a factor in keeping food moist and therefore needs to be maintained thoughout the cookout.
To be fair, there's little evidence to suggest that the humidity has a significant impact on moisture retention I still think that it helps preserve the outside of your meat from turning too dry.
More importantly it should help meat reach its desired "done" temperature because the humidity will stop the meat sweating moisture. It's this sweating process that can cause the meat temperature to plateau for a few hours before finally hitting the desired temperature - you'll notice this particularly when smoking a pork butt.
In effect the water bath acts like a sauna or steam room where the high humidity reduces your body's ability to evaporate moisture from the surface of the skin. Your body can't cool down and therefore your body core temperature rises. Cooking in a humid environment will have the same effect on the meat.
In addition the water bath acts as a thermal store absorbing any sudden changes in the strength of your fire and so making temperature fluctuations in your food chamber less dramatic. This can be important when tending your fire and adding new coals.
This point is best demonstrated by adding cold water to a water bath, note how it drains your smoker of temperature and how you need to adjust the air vents temporarily to bring the food chamber back up to the desired temperature. To avoid this, fill your smoker water bath with warm water.
To some BBQ enthusiasts this point about the smoke ring might be the one single thing that necessitates a water bath from now and evermore.
When you cut into a piece of smoked meat, whether that be ribs, brisket or whatever look carefully at the cross section of the meat and you'll probably see a pink ring about 5mm thick around the perimeter. This is what's referred to as the smoke ring.
It is revered among competition barbecue teams and judges and it forms when nitrogen oxide comes into contact with raw meat.
Nitrogen oxide is one of the gases released when wood or charcoal is burned at high temperature. The nitrogen oxide reacts with raw meat to give the pink colour.
Your water bath comes into play because the moisture deposited on the meat from the evaporation of the water bath provides the ideal environment for the nitrogen oxide to dissolve into the water and so penetrate the raw meat.
In other words, the humidity from the smoker water bath can be shown to increase the thickness of the smoke ring on a piece of meat. The sign of a great pit master!
If you use your smoker water bath as a drip tray too, any juices that come off the meat will add flavour to the water bath and those flavours get more concentrated as the moisture evaporates. Many a time I’ve used the juices of the meat to make the gravy.
Make a roux using a spoonful (or 2) of oil and a spoonful of flour. Use the juices to ease the roux to the consistency you need and if you need more liquid you can always add some stock or white wine.
When I last smoked a piece of brisket I used a rub and a sauce. The drips landed in the water bath / drip tray and the reduced liquid at the end of the cookout was poured into a plastic container and put straight into the freezer. Perfect marinade for the next steak cookout.
I guess it just boils down to not wasting a thing.