Tips for scaling recipes to fit a frame

[Pastrypastmidnight]

Forgive me if this has been addressed—I searched and didn’t find anything. 

 

Last night I made two flavors of Boiron recipe pâte de fruit. One was blackberry and one lemon. The lemon had you cook a large amount of pear purée (1000g) and later add 970g lemon and cook again as opposed to the blackberry with 1000g fruit. The sugars were not identical but were fairly close. So, clearly the lemon makes more and when poured into the same size pan/frame will reach a different height. How do I figure out how much to make to fit a certain frame? Is there a more elegant solution that making a full recipe, pouring it into the desired receptacle to the desired height, weighing the excess and weighing the amount in the pan/frame and using that to scale the recipe? What about ganache/gianduja/etc.? Is there a ballpark grams-per-cubic-mm or something?

 

You can see the height difference here (both were half the Boiron formulas poured into 8x8 pans). There is much more lemon due to the added pear, but not quite double I’m guessing because the lemon is mostly water and a lot of it boils off. 

 

[Goober]

Hi @Pastrypastmidnight

 

As you have poured both quantities into the same sized receptacles, you can determine the percentage difference without weighing either of them, by instead using the ratios.

 

1. Get a ruler and measure the height of each batch in millimetres.

2. Divide the lower height by the taller height (eg 3.3 / 4 = 82.5% ( 0.825 * 100))

3. 100% (the larger measurement) - 82.5% (smaller measurement) = 17.5% (the difference), which means the shorter batch is 17.5% smaller than the large.

4. Applying this to your larger recipe to bring it to the same volumetric size is as simple as multiplying each ingredient in the larger recipe by whatever the original percentage difference came to (0.825). So if you had 1000g (1kg) of pear puree in the larger batch, you would calculate ((1000 * 0.825) =  825g).

 

I was able to measure the ratio from the picture you provided and 17.5% is the actual difference it came to. I would reduce your recipe by 12-15% in the next batch.

 

You can also work the opposite way, you can purposely make the batches smaller than the height of the receptacle (say, 2 half, or even 2 quarter batches) and figure out the volume required by substituting the receptacle heigh for your larger measurement in the calculation mentioned above (if that makes sense).

 

This only works when using the same sized receptacles, which may be obvious, but worth mentioning none the less. This also assumes the total batch was poured into each receptacle and that the larger batch didn't fill the receptacle and have some amount remaining that was kept aside.

 

[Tri2Cook]

If the recipe doesn't already tell you the batch weight, just add the ingredients together to get a total weight. If the blackberry recipe makes 1500 grams and the lemon makes 2000 then reduce everything in the lemon recipe by 25%. You probably won't get lucky and have it be a nice, convenient percentage like that but any percentage is easy to work out with a calculator.

[Pastrypastmidnight]

6 minutes ago, Tri2Cook said:

If the recipe doesn't already tell you the batch weight, just add the ingredients together to get a total weight. If the blackberry recipe makes 1500 grams and the lemon makes 2000 then reduce everything in the lemon recipe by 25%. You probably won't get lucky and have it be a nice, convenient percentage like that but any percentage is easy to work out with a calculator.

Thanks you! And I think that works fairly well for a ganache where most of the measured weight makes it into the final product (although it’s not easy to tell how that weight—i.e. how high up the pan it will go—will fit into your frame), but I’m a little stumped with recipes that include reducing down the liquid, like a caramel or a pate de fruit, because different fruits have different water contents, etc. So aren’t different amounts of solids left behind after the boiling process? The lemon took waaaaaaay longer to make—there was also a lot more water to boil away. So the final product masses can vary as percentages of the initial ingredient masses, depending on the flavor. 

[Pastrypastmidnight]

4 hours ago, Goober said:

Hi @Pastrypastmidnight

 

As you have poured both quantities into the same sized receptacles, you can determine the percentage difference without weighing either of them, by instead using the ratios.

 

1. Get a ruler and measure the height of each batch in millimetres.

2. Divide the lower height by the taller height (eg 3.3 / 4 = 82.5% ( 0.825 * 100))

3. 100% (the larger measurement) - 82.5% (smaller measurement) = 17.5% (the difference), which means the shorter batch is 17.5% smaller than the large.

4. Applying this to your larger recipe to bring it to the same volumetric size is as simple as multiplying each ingredient in the larger recipe by whatever the original percentage difference came to (0.825). So if you had 1000g (1kg) of pear puree in the larger batch, you would calculate ((1000 * 0.825) =  825g).

 

I was able to measure the ratio from the picture you provided and 17.5% is the actual difference it came to. I would reduce your recipe by 12-15% in the next batch.

 

You can also work the opposite way, you can purposely make the batches smaller than the height of the receptacle (say, 2 half, or even 2 quarter batches) and figure out the volume required by substituting the receptacle heigh for your larger measurement in the calculation mentioned above (if that makes sense).

 

This only works when using the same sized receptacles, which may be obvious, but worth mentioning none the less. This also assumes the total batch was poured into each receptacle and that the larger batch didn't fill the receptacle and have some amount remaining that was kept aside.

 

Thank you for typing that all out. That does make sense. And I suppose, I can calculate the grams per mm cubed based on the pan I used and then convert that for a frame with a bigger footprint?

 

And my kids are always trying to tell me they’ll never use math in real life  .

[Goober]

Pretty much.

 

The method Tri2Cook mentions is a good back of the napkin method, and you are right, with different moisture contents within those ingredients, it will vary, but it will give you a decent idea of the difference between the two batches. It will get you close the first time. You can then measure to refine it if you want. You have options - which is nice.

 

 

 

 

 

[Tri2Cook]

7 hours ago, Goober said:

Pretty much.

 

The method Tri2Cook mentions is a good back of the napkin method, and you are right, with different moisture contents within those ingredients, it will vary, but it will give you a decent idea of the difference between the two batches. It will get you close the first time. You can then measure to refine it if you want. You have options - which is nice.

Yeah, it's just a quick and easy way to get in the ballpark. There are more accurate methods for zooming in closer on an exact match, such as you provided. I figured for something like this, the ballpark is close enough. A little too much isn't as bad as a lot too much. You can dump a little too much in a bowl or something, let it set and do a little quality control (pronounced: snacking) without getting into your production pieces. 

[Pastrypastmidnight]

7 minutes ago, Tri2Cook said:

Yeah, it's just a quick and easy way to get in the ballpark. There are more accurate methods for zooming in closer on an exact match, such as you provided. I figured for something like this, the ballpark is close enough. A little too much isn't as bad as a lot too much. You can dump a little too much in a bowl or something, let it set and do a little quality control (pronounced: snacking) without getting into your production pieces. 

I like how you think  .