November 16, 2010 - 1:32pm

## Adjusting ingredients to increase the size of Boulder's Best White Bread

Does anyone have any experience with increasing the amount of flour in Susan Purdy's Boulder's Best White Loaf? I want to make larger loaves. If I use 50% more flour, by how much do I adjust the amount of yeast etc. at 5,000 and 7,000ft?

Scale everything in the recipe the same (easier if you're using metric weights, but not imposible even with funky U.S. volume measurement).

If you halve the flour, then halve the water, halve the yeast, halve the salt, ...

If you add 50% more flour, then add 50% more water, 50% more yeast, 50% more salt, ...

If you need to "adjust" the recipe, for example for funky flour or for elevation, do that

beforeyou scale the recipe up or down. If the recipe already works, it's obvious you don't need any more adjustments at that size, and you won't need any adjustments at any other size either - just scale the recipe up or down.(Ease of scaling a recipe up or down is one [not the only:-] reason for both "baker's percentages" and "measurement in grams".)

Why is it more or less difficult to scale "funky US volume measurements"?

Twice one cup is.. two cups. Half of one cup is.. half a cup. As an added bonus, 1/3 of one cup is.. a third of a cup, which is probably there in your set of measuring cups.

As noted, volume measurements scale readily for "nice" amounts (half, double, etc.). The real issue shows up when you try to scale by arbitrary amounts (this isn't just "theoretical" - most recently I had to do this to get "just the right amount" to fill a disposable foil loaf pan).

Some specific examples of scaling that isn't so easy with "funky US volume measurements":

2/5 of a cup is?

11/7 of a cup is?

1/3 of a teaspoon is?

1/4 of a Tablespoon is?

Even many things that can be figured out in the abstract aren't so easy when both my hands are covered with flour and the mixer is about to "walk" off the edge of the counter. Fortunately I have no difficulties at all doing these kinds of things with recipes in "grams".

11/7 of 415 grams is? Quick now! Your hands are covered with flour! It's easy -- with a calculator.

It's helpful to know that the usual american measure has 16 tablespoons in a cup and 3 teaspoons in a tablespoon, so 48 teaspoons in a cup (which is quite nice, since you get halves, thirds, quarters, sixths and so on easily and exactly). After that, it's just arithmetic, same as grams.

And, actually, I can do 11/7 of a cup in my head fairly accurately. It's 1 cup plus 4/7 which is in turn 3.5 sevenths (1/2) plus 0.5 sevenths (1/14). So 1 and 1/2 cups plus a tablespoon (1/16) plus a trifle more. If the best I can do with 'a trifle more' is to get it somewhere between 0 and 1 teaspoon, my error is plus or minus 0.76 percent (and I'm pretty sure I can do better than that).

Similarly 2/5 cup: 2/5 is six fifteenths which is a bit more than six sixteenths which is six tablespoons. Leaving it at that gets you 6.25% low. In my head I'm a little worried about HOW low I am, though, so I also think 2/5 is 20/50 which is a little smaller than 20/48, which is 20tsp, or 6T + 2t. Better make it 6T plus 1t. Now I am 0.4% off (in my head, I don't really know how close I am, but I since I have it bracketed by 6T and 6T+2t I know I'm not far off).

Not everyone is all that comfortable juggling 48ths around in their head, but most people should be able to handle 16ths, and if they can't, well, there's always the calculator. You know, the thing you use for "11/7 of 415 grams."

Getting 1/3 tsp accurate is hard no matter what you're doing. I use a heaping 1/4 tsp. Since 1/3 tsp is in the range of 1 gram for most baking ingredients, you're going to need QUITE an accurate scale to be closer than I am with my nasty old teaspoons.

1/4 T is in the 3 gram range, which is going to be a little more tractable for most scales, but a scant teaspoon is probably going to work quite nicely. Your scale might be a little more precise.

Seriously, it's not all that hard, and since the numbers are actually pretty well chosen (16s, 12s, 3s and so on) you can get pretty darn close in your head, on the fly, when your hands are covered with flour. Metric drives me nuts, because being based on tens, and measuring everything in grams (et al) (or disguised grams: moving the decimal place around is just trickery).

Here's a better example (granted, my previous ones were a bit unrealistic:-)- I have a recipe that calls for 4-1/4 cups of flour. But the loaf is too big to eat by myself, so I want to scale it down a little to 2/3 recipe. I can eventually figure out that 2/3 of 4-1/4 cups is 2 cups + 1/2 cup + 1/4 cup + 1 Tablespoon + 1 teaspoon ...but I'd rather not. That's a personal preference, and all the math in the lengthy post above has just strengthened it.

Yeah, some people can scale any volume measurement easily. And yeah some people really dislike things based on tens.

But I'm not one of those people. I personally much prefer grams.

One of my points (which I probably failed to state clearly before:-) is that in practice I don't use fractions

at all. One (just one) quick division with the calculator before I start tells me I'm scaling every ingredient in the whole recipe by 157%. So using metric grams and what I find the easiest way to calculate, this would be:157% of 415 grams is?

You missed the real advantage of having to do the complex "funky" calculations in your head - it is an important mental exercise that is a crucial part of ensuring that we will still have have the ability to go on cooking into old age. Those who simply do one quick calculation with a calculator are exercising only their digit finger which will not help delay the onset of senility :-)

Hi Ifanpayne and welcome to TFL

The good thing about working in percentages is everything stays relative so if you were happy with the original formula and you want to increase or decrease it is a simple thing to do, In your case 50% more then all ingrediants will be 50% more.

Regards Yozza @ sealevel or not far above

Thanks for the clear and prompt replies. Purdy's recipes work every time for me both in Socorro at almost 5,000ft and at the weekends in Santa Fe at 7,000ft..

If you're increasing the size of loaves, you may need to change the baking time, too. It depends on shape, too. Increasing only one dimension doesn't change much, changing all three does.

Thanks, that's a good point.

A question please, it seems to me I read somewhere that increasing amounts in a bread recipe equally, does not apply to the yeast. Does this ring a bell with anyone and am I wrong about that. I have always wondered how you would judge the increase in the yeast if you were doubling or tripling the recipe. Or do you apply the same increase to the yeast always.

Thanks, Jean P. (VA)

This is a good question, especially as to how it relates to cooking at altitude where less yeast is required than at sea level.