Converting from one kneading style to another isn't difficult. The two things that might change are the amount of time you knead, and the order you add ingredients.
When it comes to timing, it's best to judge by how the dough looks and feels, but it's useful to know when to stop and check the dough. If you’re converting a hand-kneaded recipe to the stand mixer, the kneading time is just a little bit shorter. If you’re converting from a food processor recipe, the kneading time will be considerably longer, but not much more work.
The good news is that since kneading progresses at a fairly slow pace, you can see the gluten developing and monitor its progress as it changes from a shaggy mass to a smooth, silky dough. And you can stop the mixer and reach in and feel the development as well, just as you would if you were hand kneading.
A good recipe will give you visual cues to look for that will indicate whether the dough has been kneaded enough. If not, you can still use the recipe's formula, but rely on your own cues to determine whether it has been kneaded enough. A dough that is fully kneaded (for a recipe that won’t have an overnight rest in the refrigerator) will be smooth and elastic. If you’re not sure, you can also use the windowpane test to determine whether the gluten has properly been developed.
Converting a recipe to the stand mixer might also require changing the order in which you add ingredients. It’s most similar to hand kneading. It might require a few more changes compared to using a food processor.
With a stand mixer, it’s common to start with the liquid and yeast in the bowl of the stand mixer, and add the dry ingredients to the liquid. Some recipes start with flour in the stand mixer bowl, proof the yeast in a separate container, then add the proofed yeast to the flour in the bowl. That doesn’t accomplish much except dirtying one more thing to wash later, so if you’re converting a recipe, do it the easy way. Proof the yeast in the stand mixer bowl.
Unlike food processor recipes, if the yeast needs to be proofed, it is generally done in all of the recipe's water. Any additional liquid ingredients are added at room temperature – not chilled, as with the food processor.
If you’re using instant yeast and don’t want to proof it (you don’t have to, but you can if you want to) the yeast can be mixed directly with the flour and sugar, if you’re using any. The water added to the dough is warm, rather than cold. If you’re not sure how warm, check out this post about water temperatures.
Some recipes written for the stand mixer call for doing the initial mixing with the paddle attachment, but I find that unnecessary, and I never do that when converting a recipe. If the dough hook isn't doing a good enough job mixing the wet and dry ingredients, it’s just as easy to mix the flour and liquids with a spoon before you begin kneading, much like you mix the wet and dry before you hand knead. Most of the time, though, the dough hook does a fine job mixing the ingredients at low speed.
There's some debate among bread authorities over the need to add salt and oil at the end of mixing. While the stand mixer has enough power to develop the gluten whether salt and oil are added earlier or later, I almost always add them at the end of kneading unless there's a reason they need to be added sooner. Adding them at the end is one more little step compared to the food processor method, but it’s not difficult.
The stand mixer is nowhere near as fast as a food processor, but the kneading is just as effortless, and it’s unlikely to overheat or overknead dough even if you leave it running longer than required. It's also gentler to the developing gluten than a fast-spinning blade.
With a stand mixer, it’s fairly easy to correct a dough’s hydration by adding more liquid or flour. It’s easier than a food processor, where you risk overheating or overkneading. While adding flour to a hand-kneaded dough is simple, adding water is trickier. With a stand mixer, the dough might slosh around a bit after you add water or slide around the bowl after you add flour, but if added in small doses flour or water will incorporate in a short time.
A stand mixer is efficient at kneading both wet and dry doughs, which is both good and bad. It can be difficult for a new baker to tell whether the dough is wet or dry while the mixer is running, so it’s important to follow a good formula rather adding more and more flour as many stand mixer recipes suggest. While it’s easy to adjust the hydration, it’s also easy to add too much flour and end up with a dry dough that the stand mixer has no trouble kneading.
The stand mixer is less abusive to add-ins than a food processor, but not as gentle as hand kneading. Delicate add-ins will break up at least a little bit, but sturdier items will emerge unscathed.