Smoking time depends very much on what you are smoking and the size if it.
It is possible to smoke meat too much, it is important not to strangle the original flavor of what you are smoking.
Mussels for example, should only have a couple of minutes, since they have a very delicate flavor. Fillet of trout should have some 20 minutes, sausages a couple of hours depending on the stuffing and a whole ham even longer, maybe a day or two.
Smoke is not necessarily most effective at the beginning of the cooking process. Some meats may benefit from being cooked first, followed by smoking for flavor.
When I make spare ribs for a lot of people it can be cumbersome to do it on the barbecue. Instead I divide the process up.
- Boil the meat
- Smoke the meat (to give it the taste of barbecue)
- Marinate the meat
- Finish under the broiler
Start by estimating the accuracy of your temperature sensor and controller. You're going to need to do some comparisons with reliable thermometers for this step. I'm guessing you don't have any laboratory grade thermometers at home that have recently been professionally calibrated. (Who does, really?)
Start by finding two or three digital cooking thermometers (preferably different models) that seem trustworthy. Then calibrate your PID controller by measuring the temperature of a mixture of equal parts crushed ice and water. It should be 0 °C. While you're at it, use the ice slush to check the accuracy of the cooking thermometers you found. Recalibrate or replace them as needed. Finally, heat some water to around 60 °C (or whatever temperature your think you'll be using most often for cooking). Then measure the temperature with your PID controller and the cooking thermometers. That should give you a pretty good idea of how accurate your PID controller will be during cooking. (If you find that your PID controller is accurate at ice temperatures, but quite a bit off at higher temperatures, you likely need a new temperature sensor.)
Sous vide accuracy is frequently in the neighborhood of +/- 0.1 °C, but +/- 0.5 °C is often good enough. I'm not sure what "low accuracy" means, but let's say, for example, that you estimate your accuracy to be +/- 2.0 °C. In that case, simply raise the temperature setting by 2 °C to compensate for the margin of error. It might result in a different level of doneness than you want, but the food will probably be safe.
Take a look at Douglas Baldwin's A Practical Guide to Sous Vide Cooking. Not only does it have some excellent recipes for beginners, but it also has some great safety information. If the food is to be consumed by pregnant women, you don't just want it to be cooked. You want it pasteurized. The guide includes tables for looking up the pasteurization time for fish, poultry, and meat (beef, pork, and lamb). If the meat is starting frozen, add about 30 minutes to the cooking time. If a recipe's going to take too long, use the tables to adjust the meat thickness or temperature in order to reduce the cooking time to your preference. Keep in mind that your shouldn't start the timer until the food is in the water bath and the water is up to temperature. So, save time by heating the water first thing when you're ready to cook.
Best Answer
There are smoke extract products available, such as Liquid Smoke and others with the type of wood smoke flavor desired being specified. With only a few hours to work with, you may wish to inject the solutin to speed up penetration into the meat. Brine or marinade diluents may be options to explore depending on your desired outcome.
Even so, minimal " equipment " such as the injection syringe and a container with some means of covering for the leg would be helpfull, or at least a foil or other wrapping for the lamb to keep juice in and atmosphere out.