Yay! Baker's math FINAL clicked for me, like, last month. Now when I read these "lessons" I am so thrilled to connect the dots... Thank you for posting!

So with preferments or porridges how do you account for the amount of water which has evaporated? In the case of porridges like oatmeal, a significant amount of the water was boiled off in the cooking process.

Benjamin - Actually, as long as you are careful when making them, you don't really need to boil porridges to cook them. Which means you can pretty much account for nearly all the water you started with. (Starches gel well below the boiling point, so all you need to do is keep the temps at a very gentle simmer.) What little that does cook off should be insignificant.

This is more of a theoretical question than a practical one, but I am curious. Can typical home-cookbook recipes for a couple loaves of bread really be scaled up successfully to bakery proportions of dough? It just seems like, notwithstanding the correct use of percentages, yeast and salt (or other ingredients) might need further adjustment for really large quantities. I don’t plan on scaling up my go-to ATK Wheat with Rye and Wheat Germ recipe to 100 loaves, but wondered how the yeast, especially, would respond.

You often read that scaling recipes requires adjusting yeast amounts, but IMO that's not true. Ratios are ratios. 100 loaves worth of dough in one tub is identical to 100 individual loaves of dough in separate containers. The only reason I can think of that larger quantities would behave differently to larger ones is that the larger mass of dough would be slower to cool down or warm up and would thus ferment at a different rate than many smaller ones.

It looks like past me was correct. I used to count 50% of the levain as flour weight and 50% of it as water weight in my recipe when calculating hydration. Then I counted the levain as a separate entity because some bread bakers do it and for simplicity. Now I might change it once again.

Yea was gonna mention that 5% starter won't count as much as 20% starter and gluten content affect hydration more so it doesn't really matter that much. I'm not gonna change my recipe because I like the round even numbers of 500g flour, 100g starter, etc. and the extra hydration is probably good.

Chiming in long after the fact with a question: I'm confused about how the water and flour comprising the levain are factored into the total. If I'm using a levain of, say, 50g flour and 50g water, do I reduce the amounts of flour and water in my formula by 50g each to account for those ingredients in the levain?

Never too late to chime in here, Eric. And yes, that's right. In the "total formula" section of my recipes, the weight of the water and the flour in the preferment has been added to the water and flour in the dough. The levain % at the end of that section is not part of the baker's percentages but just a way of indicating how much levain is used.

A useful exercise is to look for a recipe that doesn't have baker's percentages (and does have a preferment like a levain) and figure the percentages out. After doing that a few times, it will make more sense.

I think it would be helpful (both here and in future editions of your pocket companion) to show an example of converting from percentages for a recipe containing a preferment. I just had to do it and was able to figure out our, but was initially frustrated that there was extra math I didn't know about! :)

Jason - Not sure what you mean by "converting from percentages for a recipe containing a preferment". Can you explain what is missing from what is already here?

Sure, no problem. So in the refinements for Lesson 1 above, you calculate an example for the total amount of flour for a yeasted dough. Then, in part two of the refinements, you calculate an example for the total amount of flour in a recipe that contains a preferment, adding the 25 g of flour from the levain to the total flour amount equaling 500 g.

In Lesson 2, "Converting from Baker's Percentages", show how to calculate the *formula conversion factor* to get from baker's percentages to an actual recipe for the size dough you want, but this is only done for a yeasted dough. In a dough with a preferment, you have to do an additional calculation for the levain. You need to know how much levain (grams) to make and also how much flour and water is contained therein to be subtracted from the amounts you add during mixing.

For example, I made your high-hydration focaccia the other day and wanted to figure out how make an 800g dough. My formula conversion factor came to 4.2, which meant the 90% bread flour in the recipe came to 378g _in total_ and the 85% water came to 357g _in total_. However, that recipe contains a 25% levain which multiplied by 4.2 comes to 105g. That levain, assuming 100% hydration, would contain 52.5 g of flour and 52.5g of water. So, the 378g of bread flour you would add during mixing becomes 325.5g (378 - 52.5) and the 357g of water you would add during mixing becomes 304.5g (357 - 52.5). If you don't do that extra math and just add 105g of levain to your 800g dough, well it probably wouldn't ruin your dough, but it wouldn't be accurate either.

I would think at least a note that mentions you will need to consider the flour and water in your preferment in your calculations would be helpful. An example would be even better. Thanks!

Jason - I see what you mean. The thing is, it's probably easier to just sort out the overall formula and then back calculate the preferment, rather than work with the conversion factor directly: sort out the preferment or prefermented flour percentage in the original recipe, convert the recipe to the new scale, and then just "pull" the correct amount of flour and water from the total to determine the final weights of both the pf and the final dough. Because the preferment is a mixture of components, it's confusing to express it as one of the "units". But I can definitely try to add this explanation somewhere.

Yay! Baker's math FINAL clicked for me, like, last month. Now when I read these "lessons" I am so thrilled to connect the dots... Thank you for posting!

You are a bread god!

ha! Hardly, just a dedicated acolyte.

Thanks for such a clear and concise explanation!

So with preferments or porridges how do you account for the amount of water which has evaporated? In the case of porridges like oatmeal, a significant amount of the water was boiled off in the cooking process.

Benjamin - Actually, as long as you are careful when making them, you don't really need to boil porridges to cook them. Which means you can pretty much account for nearly all the water you started with. (Starches gel well below the boiling point, so all you need to do is keep the temps at a very gentle simmer.) What little that does cook off should be insignificant.

I would be interesting to weight the porridge before and after to see how much is lost.

you certainly could!

This is more of a theoretical question than a practical one, but I am curious. Can typical home-cookbook recipes for a couple loaves of bread really be scaled up successfully to bakery proportions of dough? It just seems like, notwithstanding the correct use of percentages, yeast and salt (or other ingredients) might need further adjustment for really large quantities. I don’t plan on scaling up my go-to ATK Wheat with Rye and Wheat Germ recipe to 100 loaves, but wondered how the yeast, especially, would respond.

You often read that scaling recipes requires adjusting yeast amounts, but IMO that's not true. Ratios are ratios. 100 loaves worth of dough in one tub is identical to 100 individual loaves of dough in separate containers. The only reason I can think of that larger quantities would behave differently to larger ones is that the larger mass of dough would be slower to cool down or warm up and would thus ferment at a different rate than many smaller ones.

It looks like past me was correct. I used to count 50% of the levain as flour weight and 50% of it as water weight in my recipe when calculating hydration. Then I counted the levain as a separate entity because some bread bakers do it and for simplicity. Now I might change it once again.

If it's a tiny amount it won't effect the result much, but you can't really ignore it if you want to be accurate.

Yea was gonna mention that 5% starter won't count as much as 20% starter and gluten content affect hydration more so it doesn't really matter that much. I'm not gonna change my recipe because I like the round even numbers of 500g flour, 100g starter, etc. and the extra hydration is probably good.

Chiming in long after the fact with a question: I'm confused about how the water and flour comprising the levain are factored into the total. If I'm using a levain of, say, 50g flour and 50g water, do I reduce the amounts of flour and water in my formula by 50g each to account for those ingredients in the levain?

Never too late to chime in here, Eric. And yes, that's right. In the "total formula" section of my recipes, the weight of the water and the flour in the preferment has been added to the water and flour in the dough. The levain % at the end of that section is not part of the baker's percentages but just a way of indicating how much levain is used.

A useful exercise is to look for a recipe that doesn't have baker's percentages (and does have a preferment like a levain) and figure the percentages out. After doing that a few times, it will make more sense.

I think it would be helpful (both here and in future editions of your pocket companion) to show an example of converting from percentages for a recipe containing a preferment. I just had to do it and was able to figure out our, but was initially frustrated that there was extra math I didn't know about! :)

Jason - Not sure what you mean by "converting from percentages for a recipe containing a preferment". Can you explain what is missing from what is already here?

Sure, no problem. So in the refinements for Lesson 1 above, you calculate an example for the total amount of flour for a yeasted dough. Then, in part two of the refinements, you calculate an example for the total amount of flour in a recipe that contains a preferment, adding the 25 g of flour from the levain to the total flour amount equaling 500 g.

In Lesson 2, "Converting from Baker's Percentages", show how to calculate the *formula conversion factor* to get from baker's percentages to an actual recipe for the size dough you want, but this is only done for a yeasted dough. In a dough with a preferment, you have to do an additional calculation for the levain. You need to know how much levain (grams) to make and also how much flour and water is contained therein to be subtracted from the amounts you add during mixing.

For example, I made your high-hydration focaccia the other day and wanted to figure out how make an 800g dough. My formula conversion factor came to 4.2, which meant the 90% bread flour in the recipe came to 378g _in total_ and the 85% water came to 357g _in total_. However, that recipe contains a 25% levain which multiplied by 4.2 comes to 105g. That levain, assuming 100% hydration, would contain 52.5 g of flour and 52.5g of water. So, the 378g of bread flour you would add during mixing becomes 325.5g (378 - 52.5) and the 357g of water you would add during mixing becomes 304.5g (357 - 52.5). If you don't do that extra math and just add 105g of levain to your 800g dough, well it probably wouldn't ruin your dough, but it wouldn't be accurate either.

I would think at least a note that mentions you will need to consider the flour and water in your preferment in your calculations would be helpful. An example would be even better. Thanks!

edited Jun 17, 2023Jason - I see what you mean. The thing is, it's probably easier to just sort out the overall formula and then back calculate the preferment, rather than work with the conversion factor directly: sort out the preferment or prefermented flour percentage in the original recipe, convert the recipe to the new scale, and then just "pull" the correct amount of flour and water from the total to determine the final weights of both the pf and the final dough. Because the preferment is a mixture of components, it's confusing to express it as one of the "units". But I can definitely try to add this explanation somewhere.