In the realm of baking, I suspect that many common rules of thumb were once the habits of a certain baker, and got passed down from generation to generation until they were simply accepted as a matter of fact. While some tips, like pausing to scrape down the bowl and beater, are worthy of a place in pastry canon, others are simply a waste of time or ingredients (or both).
Take, for example, the oft-repeated advice that baking soda should be replaced periodically to ensure your supply is always fresh. Total hogwash, because, even in relatively hot and humid conditions, an open container of baking soda has been scientifically proven to retain its potency for years (more on that here).
What really bugs me is the age-old advice that berries should be tossed in flour before they're folded into a batter. The logic is that flour allows blueberries to magically hover above the pan, thanks to...reasons. I'm not sure if the particles of flour are supposed to transform into tiny grappling hooks or what, but we've all seen enough bottom-heavy blueberry muffins to know that this "trick" is total bunk.
Here we have fresh blueberries tossed in flour, stirred into my favorite muffin batter, and baked.
Guess what? The blueberries still sank to the bottom of the pan, because that's how gravity works. I'm not going to invest extra effort in a trick that doesn't do what it purports to.
This isn't to say that I'm willing to accept blueberries at the bottom of every muffin—just that I need any countermeasure to be demonstrably effective. So I came up with this simple yet totally foolproof technique: Before adding the blueberries, drop a scoop of plain batter into the bottom of each muffin cup, then fold in your berries and portion out the rest.
Boom. Problem solved.
Insulating the berries from the pan ensures that each muffin is easy to remove, since no bubbling juices will glue them to it (a reality that can also wreak havoc on a paper liner, if you choose to go that route). Another bonus of keeping blueberries away from the pan? Nice, even browning that makes soggy-bottomed muffins a thing of the past. (More on the role of muffin pans in browning here.)
How does this hold up to other techniques? See for yourself in the photo below.
On the far left, we have muffins made with blueberries tossed in flour. On the far right, we have muffins made with plain blueberries stirred right in. In the middle, muffins made with a cushion of batter, but otherwise no treatment for the berries.
While the flour toss does seem to minimize bleeding in the muffins on the left, that's only a benefit if the berries are tossed with a portion of flour reserved from the recipe itself; otherwise, extra flour will only make blueberry muffins seem dry.
So quit wasting time and energy tossing your berries in flour, since it's a trick that doesn't work. Instead, use my method (whether you use my recipe or your own), and you'll be baking up flawless blueberry muffins in no time flat.