Pod4477,

To give you an idea as to how the preferment dough calculating tool works, assume that you want to use a specified amount of biga that has a hydration value of 50%. Let's assume that the amount of biga you want to use is 5% of the total dough ball weight. Let us further assume that you want the biga to use 100 grams of flour. So, with the flour at 100 grams, you need 50 grams of water to have a hydration value of 50%. Now, if you look at the preferment dough calculating tool at https://www.pizzamaking.com/preferment-calculator.html, You will see the statement:

*Note: Preferment percentage of water = (weight of water divided by total weight of preferment) x 100. *

Forgetting for the moment the amount of yeast you would like to use in your biga, the total biga weight comes to 100 + 50 = 150. That means that the preferment percentage of water is 50/(150) = 33.3%. That is the number that goes into the entry box entitled "Enter the preferment's percentage of water". Of course, in your case, you will not want to forget to add the biga yeast when you actually make the biga, the effect of which is to increase the weight of the biga. However, if the amount of yeast is small, it is unlikely to change the 33.3% number by a material amount.

As you correctly noted, the 5% number for the total biga quantity, measured with respect to the total dough weight, is entered in the box "Enter desired preferment amount".

For the other entries in the preferment dough calculating tool, you will rely on the basic dough recipe you will be using, most notably the baker's percents for the recipe you will be using but also the numbers that go into the other entry boxes. When done, the tool will specify the basic dough recipe numbers (the "Total Formula"), the numbers for the biga (the "Preferment"), and the numbers for the remainder of the dough (the "Final Dough") to which the biga is added. However, from the amount of yeast shown in the Final Dough you will want to subtract the amount of yeast used in the biga. Some of the final numbers may not be exact but if the amount of yeast used in the biga is small, the final numbers may be close enough for your purposes. Unfortunately, the fact of the matter is that the preferment dough calculating tool was not designed for preferments containing commercial yeast.

As for your question in the last paragraph of your post, I don't quite remember what experiment you had in mind that I was conducting but the preferred method for using a natural preferment is to discard part of it and add more new flour and water to refresh the preferment. However, I do remember conducting at least one experiment where I used an unfed preferment. That might work but you would have to run tests to determine the amount to use and to see whether such a preferment imparts the desired flavor for the finished crust.

Peter

Thank you so much! I knew my math was wrong. That water value was the part I was stuck on, but your awesome explanation really helped me. So I came up with a dough calculation with using a 50% hydration biga, not taking into account any yeast added to the biga. I based this off the PR ingredients list I was given. Since it lists flour, water, salt, yeast, oil (in that order) I assumed they were using maybe 2% salt and 2% cake yeast. When converting the cake yeast to IDY, I used the .375% conversion number, and it came out to .75% IDY for the equivalent 2% cake yeast. You said to subtract the yeast used in the biga, and the amount used in the biga would come out to .03368 grams of IDY, if my math is correct. To get that number I based it off of that website's recommendation of using .1% IDY, and since the flour in the biga is 33.68 grams, it came out to that .03368g amount. When subtracting the .03368g IDY from 2.33g IDY, it comes out to 2.29 grams of yeast being added in the actual dough ball.

The calculation is as follows:

Total Formula:

Flour (100%): 310.29 g | 10.94 oz | 0.68 lbs

Water (58.25%): 180.74 g | 6.38 oz | 0.4 lbs

Salt (2%): 6.21 g | 0.22 oz | 0.01 lbs | 1.11 tsp | 0.37 tbsp

IDY (.75%): 2.33 g | 0.08 oz | 0.01 lbs | 0.77 tsp | 0.26 tbsp

Oil (1.75%): 5.43 g | 0.19 oz | 0.01 lbs | 1.21 tsp | 0.4 tbsp

Total (162.75%): 505 g | 17.81 oz | 1.11 lbs | TF = 0.0885942

Preferment:

Flour: 33.68 g | 1.19 oz | 0.07 lbs

Water: 16.82 g | 0.59 oz | 0.04 lbs

Total: 50.5 g | 1.78 oz | 0.11 lbs

Final Dough:

Flour: 276.61 g | 9.76 oz | 0.61 lbs

Water: 163.93 g | 5.78 oz | 0.36 lbs

Salt: 6.21 g | 0.22 oz | 0.01 lbs | 1.11 tsp | 0.37 tbsp

IDY: 2.33 g | 0.08 oz | 0.01 lbs | 0.77 tsp | 0.26 tbsp

Preferment: 50.5 g | 1.78 oz | 0.11 lbs

Oil: 5.43 g | 0.19 oz | 0.01 lbs | 1.21 tsp | 0.4 tbsp

Total: 505 g | 17.81 oz | 1.11 lbs | TF = 0.0885942

Also they may be using 1.875% salt, but to make it easier I just used 2%. My salt intake is high these days, and it usually takes more salt than the average person for me to get, what I call, even tasting food. I know that their crust does has a good amount of salt because to me it tastes very balanced, which to most people must taste actually salty. I infer from this that they must be using around that 2% of salt, since that is around what I use (1.875-2%), and mine tastes very balanced and close to theirs. I found it interest how most pizza places have a very un-salty crust, and I'm assuming this is to aid in fermentation, but really makes it bland to me, especially since I require more salt to be pleased with most foods.