What effect does the amount of stirring have on the quality of a muffin?

Answer 1

Answer

All you need to do is mix the ingredients so the flour and other ingredients are well blended. Scrape the sides of the bowl with a spatula to get any flour that may have stuck to the side of the bowl. Other than that you can stir until the cows come home and you'll have flattened muffins.

Answer

Something called "tunneling" will result if the batter is over mixed. This is when you get holes and hollow spaces in your muffins while baking, hence, the flat muffin syndrome.

That is exactly what I would have done

Answer:

The primary leavening in muffins is baking powder/ soda. (Dependent on the style of muffins) The technical term for mixing any dough is "machining". This term is used by many bakers and is used in professional cook books as something not to do when preparing muffins, biscuits and the like.

The reason is simple; the leavening is metered according to the amount of water used. The method of incorporating the moisture to the dry ingredients is "folding" to the point that the moisture is absorbed. The truth is that the water is never completely absorbed until the cooking phase. The leavening needs to absorb the water slowly to allow a "timed release" of the power of the leavening in conjunction to the heat of the oven. If the dough is over "machined", the leavening is forced to absorb the liquid faster preventing it to rise in the oven. The "holes" mentioned above is due to the leavening acting too fast causing pockets of air. (you will probably notice that the end resulting muffin is very dry too)

A good tip: mix the dry ingredients thoroughly first with a wire whisk before the introduction of any fluid.

Answer:

Another effect of stirring is the development of the gluten in the flour. Tough, chewy muffins (and pancakes) are (usually) the result of over mixing. Hence the admonition to "fold" the wet into the dry, to a "just mixed" consistency. In practice, stop mixing just before the batter is "completely mixed" and the last few bits of manipulation to get the batter into the cups and scraped off the side of the bowl will provide the last three or four strokes needed to complete the mixing. If you pay attention you will note a slightly different consistency to the last muffin filled from the first muffin filled. A typical stopping point is when a few small, pea sized clumps of unmixed flour remain in the batter. A smooth, lump free batter is too far gone for a light muffin. Light touch, light touch, light touch; that is the muffin mantra.

Answer:
Proper mixing is needed in muffins to achieve a pebble crust. Some batter require less mixing but in muffins takes not more than 25 stroke to have a good quality.