What's The Problem - #3

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Michael in FtW

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OVERVIEW of PROBLEM: Converting flour weight to volume in a bread recipe

Consul had a good observation in Problem #2 about flour weight VS. volume. So - let's play with it!

The generally accepted correct way to measure flour is to use a dry ingredient measuring cup ... use a spoon to lightly sprinkle the flour into the measuing cup until it overflows, then level it off by running a straight-edge across it. No dipping the measuring cup into the flour, and no tapping, shaking or thumping the cup to level it off! This is normally the way flour is measured in a recipe unless otherwise stated - such as in Cookwise by Shirley Corriher (see Measuring on page 11).

ASSUMPTIONS: We need to make a few assumptions here to try to avoid me leading someone off in the wrong direction this time.

1. We are using US standard weights and measures ... 1 Cup = 16 Tablespoons, 1 pound = 16 ounces, and standard 5 lb bags of flour which are labeled 5-lbs - 80 ounces - 2.26 kg (2.26 kg is actually 2268 grams).

2. The moisture content of the flour is NOT a factor. Neither is if the bag says "Pre Sifted".

3. Using the standard method of measuring flour (above) - you will be within +/- 0.02 ounce by weight per 1 Cup of flour.

4. The "serving size" information on the side of the bag is correct for US measurements (cups, spoons) and only an approximate for the metric weight conversion due to rounding errors.


HELP: You shouldn't need anything more than a simple calculator (paper and pencil also works) but here is a site that will help you with conversions if you need them: http://www.onlineconversion.com



THE PROBLEM:

You have a bread recipe that lists volumes for everything but the bread and wheat flour - and those are given in pounds and ounces .. and you don't have any scales. What to do?

The recipe calls for
1-lb 1-oz Bread flour
1-lb 2-oz Wheat flour

You've got a 5-lb bag of each ... and while you scratch your head you read the information on the side of each bag.

BREAD FLOUR: A serving size is 1/4 cup (30g) - and there are 75 servings per 5-lb bag.

WHEAT FLOUR: A serving size is 3-Tablespoons (31g)- and there are 72 servings per 5-lb bag.

Rounded to the nearest quarter-cup - how many cups of bread flour and wheat flour do you need?

BONUS POINTS: How did you calculate your answer?
 
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kitchenelf said:
I'm gonna cheat and call my friend Michael in FW - be right back :mrgreen:

Oh - come on Elf - it's not that hard if you think about it. Really no harder than: If Andy has 5 pennies and the elfen one has twice as many ... how many times can Elf throw in her 2-Cents worth?
 
Michael,
This may be too simple an answer, but I tried not to read too much into all of the information you gave us.
I am really guessing, but since 1lb. 1 oz = 17 ounces. I am saying 2 cups 1 tbsp. of bread flour

1lb 2 oz = 18 oz. so it would be 2 cups plus 2 tbsp. of wheat flour.

Is it more complicated than that?

Used a pencil and paper. Could have figured it out in my head though.
 
lyndalou - yep, it's a little more complicated than that! :wacko:

The problem is to figure out the difference between volume and weight - what volume will equal what weight. It appears that you assumed weight and volume were the same ... 1 Cup (8-oz volume) of flour is equal to 8-oz by weight.

Andy got it wrong last night .... but after I pointed him in the right direction he got it right this morning. So, trying to not give the answer away, I'll just say that the information you need to solve the problem is on the side of the bags.
 
Oh, gosh. you're right Michael, that is what I did. I'll try one more time, probably take me hours, math is not my strong suite. Do I actually have to have a bag of wheat flour? I'll check the bag in the market when I go later.
 
One cup of wheat flour and one and a 1/4 of bread? Did I go the wrong direction in my conversion? That sounds too small.
 
lyndalou said:
Do I actually have to have a bag of wheat flour? I'll check the bag in the market when I go later.

No .... doooh ....(me impersonating Homer Simpson slapping his forhead) :wacko: Go back and look at the problem again - I gave you the only important information on the side of the bag for the two bags of flour we are using in this problem. No need to buy any!

Alix: Yep, it is too small. Not sure what you did. Remember, this a baking question not a banking question ... you can't convert grams into Euros to get ounces. :LOL: If you want to work it out in metric and convert to lbs/oz - 5-lbs is actually 2268 grams. The actual weight of a serving size of Bread flour is 30.24g (they round it to 30) and the actual weight of a serving size of Wheat flour is 31.5g (they round it to 31). I'll explain more when I post the answer tomorrow night.
 
Michael, I was kidding about having to buy flour. I have to tell you that I am stumped on this one. Too much math for me, I guess. I am anxiously watching for someone to come up with the right answer, though. Good luck all.
 
lol ill figure it out. itll be a warm up for my precalc test i have today. :LOL:

so i got bread flour 3.98 cups
and wheat flour 3.03 cups

all i did was use ratios

1 serving / .25 cups = 75 servings /X
x = 18.75 cups

18.75 cups /80oz = x/17oz

x = 3.98 cups bread flour

1 serving / 3 tb = 72 servings / x
x = 216 tb

216 tb / 80 oz = x / 18 oz
x = 48.6 tb

48.6 / 16 = 3.03 cups
 
I am no good at math - I will check with my 14 year old daughter and get back to you - she just got a 98 in her last test - grade nine math... ( now she will hate me if she gets this wrong! but it will show her that YES we use math in everyday life!)
 
i'm too tired to think, so i'll have to re-read this later. i need a looooog nap first.
 
ARGH! Michael, I think I did the conversions backward. I SUCK at this. LOLOLOLOL!

To be honest you know what I would do? I would look at my bowl and start dumping stuff in it (keeping track as I go) and when it looked right I would go to town. PHOOEY! I hate it when I mess stuff up like this. I am going to take another crack at it and then wait for your solution. This is fun Michael, thanks.
 
Michael in FtW said:
OVERVIEW of PROBLEM: Converting flour weight to volume in a bread recipe

ASSUMPTIONS: We need to make a few assumptions here to try to avoid me leading someone off in the wrong direction this time.

1. We are using US standard weights and measures ... 1 Cup = 16 Tablespoons

4. The "serving size" information on the side of the bag is correct for US measurements (cups, spoons) and only an approximate for the metric weight conversion due to rounding errors.

THE PROBLEM:

You have a bread recipe that lists volumes for everything but the bread and wheat flour - and those are given in pounds and ounces .. and you don't have any scales. What to do?

The recipe calls for
1-lb 1-oz Bread flour
1-lb 2-oz Wheat flour

...you read the information on the side of each bag.

BREAD FLOUR: A serving size is 1/4 cup (30g)

WHEAT FLOUR: A serving size is 3-Tablespoons (31g)

Rounded to the nearest quarter-cup - how many cups of bread flour and wheat flour do you need?

BONUS POINTS: How did you calculate your answer?
As a mathematically challenged little old lady, here's what I came up with. I think you will need
BREAD FLOUR: ~16 1/4-cup units OR ~4 cups
WHEAT FLOUR: ~12 1/4-cup units OR ~3 cups

Here's how I arrived at my answer...

The key points from Michael's post are
> The "serving size" information on the side of the bag is correct for US measurements (cups, spoons) and only an approximate for the metric weight conversion
and
> the premise that 1 Cup = 16 TBS and therefore that 1/4 cup = 4 TBS (this is correct for liquids but not necessarily for solids like flour)

step 1: convert flour measurements to oz
REQUIRED AMOUNT IN OZ
Bread flour 17.00 oz (1 lb + 1 oz)
Wheat flour 18.00 oz (1 lb + 2 oz)

step 2: calculate what % of the total 5-lb flour sack is required, given the sack weight (80oz) and the required recipe amounts in oz
REQUIRED AMOUNT AS % OF 5LB FLOUR SACK
Bread flour 21.25% (17 / 80)
Wheat flour 22.50% (18 / 80)

Michael wants the answer in 1/4-cup units (rounded) so I can calculate the answer easily for bread flour since the serving size is in 1/4 cup units, there are a total of 75 servings in the sack and I need 21.25% (by weight) of the sack for the 17oz of bread flour called for in the recipe.
REQUIRED AMOUNT IN 1/4-CUP SERVING SIZE UNITS
Bread flour 15.94 1/4-cup units (75 * .2125)

Wheat flour is more complicated, since the serving size is 3TBS and Michael says to assume that there are 4TBS per 1/4 cup of flour
There are a total of 72 servings in the sack and I need 22.50% (by weight) of the sack for the 18oz of wheat flour called for in the recipe.
so...
REQUIRED AMOUNT IN 3 TBS SERVING SIZE UNITS
Wheat flour 16.2 3-TBS units (72 * .225)

But now I have to get my units from the 3-TBS serving size on the sack to the 1/4 cup (4 TBS) measuring unit that Michael wants.
First, I'll calculate how much wheat flour I need using TBS as the unit of the measure. I get total of 48.6 TBS (16.2 * 3) TBS.

Next, I'll divide 48.6 TBS by 4 since we assume that it takes 4 TBS flour to get 1/4 cup flour. This gives me
REQUIRED AMOUNT IN 1/4 CUP SERVING SIZE UNITS
Wheat flour 12.15 1/4-cup units (48.6 / 4)

======= COMMENTS =======

In baking, flour (and other solids) really should be weighed, not measured. For example, when I measure flour using level TBS into a 1/4 measure, it only takes me 3 TBS to make 1/4 cup, not 4 TBS.

The purchase of a "plain vanilla" digital scale (about $30) would eliminate a lot of the head scratching that went on here (including mine!).

= :) = :) cheers to all = :) = :)
 
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