Recipe ratio concern

The whole reason for bakers percentage is so a recipe  can either be scaled up or down easily. I think some authors don't think people can't do this without making a mistake and messing up rhe bread. Go ahead and make whatever quantity you want just keep the ratio of ingredients.

Assuming you are baking bread, you need to understand the Baker's Percentage, as mentioned by STUinlouisa. Once you understand how each ingredient impacts the overall formula you will scale any bread recipe effectively. 

I agree with all the comments above. Having said that, I've been working on figuring out a swiss raisin muesli bread (no recipe), and in attempt to figure out the recipe I had been making the smallest loaf I could (400 - 500gram final result) - that way if it didn't work, I wouldn't be wasting too much flour, seeds, etc. But it kept flopping on me. One day I decided to double the size and see if that helped so that while the proportions of everything was the same, the actual mass of flour dough was bigger - maybe that would help was my thought. Turns out that there wasn't enough critical mass and once I doubled the flour (and everything else in proportion), the dough came together much better. Previously I couldn't get enough gluten formed as (I think) the ground seeds were overwhelming (or cutting too much maybe) the gluten strands regardless of how many slap and folds I did. Doubling the mass dramatically changed the results. I'm still working on the other issues (it's a must-get-back-to project). But this is an example where size does matter. :)

Caveat : It could be about the mass size, or this could instead be from my lack of experience or knowledge in how this stuff all works.

I wonder about that very thing frequently.  %'s address scaling but not dough activity.  

By the way I have been wondering about your progress with the muesli bread. I did try one using a muesli blend from Daybreak Mills that I toasted and used like a porridge.  While the bread was excellent, it wasn't what I wanted.  I added a small percentage of honey but I did not include any fruit bits.  I would add more honey next time. 

But im waiting to see yours when you perfect it --

It is usually seasonings, eggs and leavening that sometimes cannot be halved. Seasonings may just have a range of volume that produces a certain flavor strength-either it disappears completely when halved or is too strong and needs to be less. Eggs can be tricky and leavening depends on the product outcome desired. Halving the volume may not produce the lift and doubling may influence the taste while being too much.

Bakers percentage makes it easier but, again, this is where the experience of the baker comes in.

The volume of the dough in relation to the machine being used for mixing or panning does affect the outcome, also. You can't properly mix 1 kg of dough in a 5 qt stand mixer OR the same holds true the other direction. You cant mix a 500g dough in a 20 qt Hobart. All things need to be considered.

My .02

Very few of the bread recipes I use are used in their original proportions. I have put the original measurements in a spreadsheet then calculated baker's percentage, and then put together a table for each recipe showing all ingredients (measured in grams) for one, two, four, six or eight loaves of 750 grams each (usually). I've never had a problem scaling up or down. I often bake four, six or eight of a kind of bread but occasionally bake only one or two, and the only thing I change is that I use the big mixer for four or more, and will do one or two in either the small mixer or by hand. I think the technique of mixing and developing the dough probably has more effect on the outcome.

One of the most useful descriptions of baker's percentage and how to use it can be found here at King Arthur Flour.

it could make scaling up or down a tricky proposition. That may be why the warning was given. 

Paul