### Author Topic: percentages  (Read 701 times)

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#### d0b0y

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• Posts: 4
##### percentages
« on: April 28, 2011, 07:28:18 AM »
when listing percentages in recipes, why do people include 4 or 5 decimal places of precision? is it really necessary? can someone show me a kitchen scale that would then be able to weigh 11.16g of salt? seems silly to me.

#### Mmmph

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• Posts: 630
• Location: ILM NC
##### Re: percentages
« Reply #1 on: April 28, 2011, 09:11:41 AM »
The dough calculators on this site do the calculations for many members. They are valuable tools and they calculate to two decimal places. Often times, people here are copying and pasting the formulae in their posts. You can round up or down as you see fit.

Check them out:
http://www.pizzamaking.com/dough_tools.html
Sono venuto, ho visto, ho mangiato

#### Pete-zza

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• Always learning
##### Re: percentages
« Reply #2 on: April 28, 2011, 09:17:10 AM »
d0b0y,

I agree that it sounds silly and I have sometimes wondered about whether we went too far with the decimal places. This was also a point that came up when member BoyHitsCar and I were designing the various dough calculating tools. We knew that there were some members (mostly techies) who had highly specialized and accurate scales. We also knew that we only going to have one chance to make a decision on how many decimal places to use in the numbers in the tools. So, we decided to go out to several decimal places and let the chips fall as they may.

I have never regretted the above decision. I have found it useful on several occasions to have the extra decimal places. For example, the other day I was trying to adjust a thickness factor value to end up with a dough that weighed exactly 11 ounces. It took me several decimal places with the thickness factor to do that. Otherwise, I got 10.99 ounces or 11.01 ounces, or something like that. Being able to use several decimal places for baker's percents has also proven to be invaluable to me personally, especially when converting recipes recited by volume measurements to weight measurements, which I perhaps do more than any other member of this forum. In so doing, I will often end up with baker's percents that go out several decimal places.

I will also often go out to several decimal places for audit purposes, for example, in the event I ever have to try to recreate my own math. I did this recently in Reply 36 at http://www.pizzamaking.com/forum/index.php/topic,13385.msg133849.html#msg133849. I knew that I didn't have to use numbers out to several decimal places but I was concerned that I might have to make changes later on as Norma conducted her experiments. Seeing how I actually came up with the numbers, even out to several decimal places, will make it easier for me to modifiy the numbers if later needed. I may be the only one on the forum who does this sort of thing, but there is a method to my madness.

I also saw recently where another member, Brian Spangler, a successful artisan pizza operator at Apizza Scholls, reported at Reply 164 at http://www.pizzamaking.com/forum/index.php/topic,11994.msg126520/topicseen.html#msg126520, in response to a question that I posed to Brian on this matter, that he uses a digital scale that can weigh out yeast to a thousandth of a gram. As you can see from my baker's percent versions of Brian's recipe, at Reply 155 at http://www.pizzamaking.com/forum/index.php/topic,7225.msg124913.html#msg124913, I went out to several decimal places on the yeast and other ingredients.

Peter

#### November

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• I just need one more electron.
##### Re: percentages
« Reply #3 on: April 28, 2011, 11:23:53 AM »
d0b0y,

It generally isn't about the precision of the weighing when working with small quantities.  As Peter's point runs parallel to, it's about being able to recognize the pattern from which the percentages came.  As I have alluded to before, many of my formulations come from specific ratios between ingredients.  Four or six decimal places allow for determining the percentages behind the percentages without losing precision for a rework of the formula.

Secondly, the number of significant digits is likely to reflect the precision requirements of the bulkiest ingredients (flour and water) and then carry down to the others.  For instance, flour may need four significant digits (e.g. 1000g), so yeast will usually end up with three decimal places (e.g. 8.000g).

Thirdly, and related to above, there is the concern for very high bulk implementations of a formula.  Some need twenty times the amount of an ingredient in a single batch than the average home baker.  If there is any science behind the choice of ingredient ratios, additional decimal places is quite useful for large batches.

Fourthly, most people use calculators.  Extra precision has never hurt anyone.  Taking the extra time to remove decimal places from a calculation before posting it seems silly.

- red.november
« Last Edit: April 28, 2011, 11:32:21 AM by November »

#### d0b0y

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• Posts: 4
##### Re: percentages
« Reply #4 on: April 28, 2011, 11:49:44 AM »
thanks for the replies! i'm an engineer, and i enjoy using numbers and calculations. it's probably why i prefer this method for creating my dough. i just find it silly to see so many decimal places used in the posts. perhaps it loses its meaning for me.

ciao,
kevin

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