A Firm and Definitive Rebuttal To...
“Why Engineers Don’t Write Cookbooks”

Here’s the original recipe, which I will provide so that I can then take potshots at it. First, the ingredients:


>Chocolate Chip Cookies
>
>Ingredients:
> 1.) 532.35 cm3 gluten
> 2.) 4.9 cm3 NaHCO3
> 3.) 4.9 cm3 refined halite
> 4.) 236.6 cm3 partially hydrogenated tallow triglyceride
> 5.) 177.45 cm3 crystalline C12H22O11
> 6.) 177.45 cm3 unrefined C12H22O11
> 7.) 4.9 cm3 methyl ether of protocatechuic aldehyde
> 8.) Two calcium carbonate-encapsulated avian albumen-coated protein
> 9.) 473.2 cm3 theobroma cacao
>10.) 236.6 cm3 de-encapsulated legume meats (sieve size #10)

Comments:

1) No engineer who was worth a shit would use five significant figures for anything in this algorithm.

1A) Any engineer who was worth a shit would provide the appropriate number of significant figures for each ingredient, with a note (if necessary) explaining the number of significant figures. I seriously doubt that anything here requires more than one figure to the right of the decimal, and several require none.

2) Gluten is a protein, purified from the milled seeds mentioned later in this paragraph. It apparently provides a lot of the gluishness that hold breads together. This amount is wildly excessive for cookies; you actually want far more starch than protein in a cookie, and any engineer who knew what the hell was going on here or expected to eat the result would never specify this material for this application. The proper specification is milled seeds of whatever Triticum variety is available fresh in your location. (A proper engineer knows and uses the correct terms for materials.)

3) This is the modern era. We do not eat quantities of hydrogenated tallow. I’m not at all sure that it’s necessary to hydrogenate tallow, btw -- I believe that it is entirely solid at room temperature without any assistance whatsoever. But we don’t eat it, and so it doesn’t make any difference. The proper specification here is the supernatant from centrifuged bovine lactiflux, if I may be high-falutin’ (and probably slightly incorrect in my Latinate derivatives) about it.

4) Items 5 and 6 appear to be identical, and both are insufficiently specified. There are several organic chemicals with that formula, all but one or two of which are incorrect for this application. The righteous engineer knows when to bring in outside expertise to make sure that items are properly chosen and specified.

Worse, it is clear that these two items refer to white and brown sugar; they cannot be identical in composition, so why specify them identically? Brown sugar should probably be specified by color (see comments on CIE chromaticity, elsewhere in this document) or by the relative levels of its constituents, at least those that contribute to color and flavor.

5) Item 7 is an inferior synthetic substitute. The righteous engineer has investigated and may even use this material, but will include a note citing the research indicating that almost nobody can tell the difference after it is heated for a period of minutes at roughly 150 celsius. (This is true -- such research has been performed, and the experimental population was notably lacking in palate. I don’t believe a single one of them could tell which was the artificial flavor and which the natural one in the baked goods or ice cream. I would love to try this test myself.)

6) The encapsulation of item 8 is not just calcium carbonate; it is a biologically generated composite material. We will, however, let this pass. The real stupidity here is the “albumen-coated protein” phrase. The albumen IS most of the protein. Engineers must know their materials, and this kind of crap does not cut the mustard!

7) Item 9, which is incorrectly capitalized and italicized (should be Theobroma cacao), calls for a certain volume of a particular tropical tree. Do they want leaf? Bark? Root bark? Sawdust? The item fails to specify, and is crap. In fact, what should be called for here is a treated extract from the seeds, and the treatment protocol (“Dutch alkali process”) should be specified.

8) Item 10 calls for “de-encapsulated legume meats”. Shelled fresh garden peas, one presumes? This, again, is insufficiently specified. Moreover, it is clear that some consumers of the product will want these, while some will not. We Shall See whether the “engineer” (not!) who compiled this garbage was savvy enough to take this into account in the rest of the algorithm.

9) Any engineer worth even a grain of salt probably refuses to let the metric system enter the kitchen. Metrics are great in the lab, but in the kitchen they are an easy path to disaster. A system based on human characteristics is much preferable.

In the olden times, people used to say “take butter the size of a walnut,” and it was entirely clear what they meant, because everybody within reach grew or used the same kind of walnuts and was familiar with them.

Later, people changed over to standardized spoons, the sizes of which were apparently based on (for example) the amount of material that would comfortably fit into the palm of a person’s hand, and so on. These measures relate to the human body in a direct and useful way, a way that the metric system cannot and does not relate, and was never intended to. The metric system has little or no place in a working kitchen. This, too, is something that any engineer should know. You don’t design something in such a way as to confuse the technician who will have to deal with it, and you don’t design it in such a way as to make it difficult to assemble or service. (Alas, altogether too many real systems have been designed by engineers who never had to deal with the results. As far as I am concerned, anyone who designs anything for manufacture should be required to participate in making them, and should also be required to test, maintain, or repair them.)


>Directions:
>
>To a 2-L jacketed round reactor vessel (reactor #1) with an overall heat
>transfer coefficient of about 100 Btu/F-ft2-hr, add ingredients one, two
>and three with constant agitation.

This is already wrong. The first direction is to “Instruct technician to mix and then beat items 4 and 5 together for minimum 15 minutes, or until exhausted.” Even before that, however, all ingredients are to be allowed to reach equilibrium at or near STP, and the furnace is to be preset and powered up. (“The impoverished student ALWAYS preheats the oven!” -- Jay F. Rosenberg)

(I am not going to talk about the missing serial comma here; you can read about that elsewhere.)

In addition to the problems already mentioned, items 1, 2, and 3 are best mixed in an open vessel without any jacket. No heat transfer is necessary (or even appropriate) at this stage, and to specify a jacketed vessel here, particularly for materials that are merely to be mixed in it and then dumped right back out again, is either stupidity or hubris.


> In a second 2-L reactor vessel with
>a radial flow impeller operating at 100 rpm,

Excessive specification. The number of RPM is to be set by the technician, who should be permitted to exercise a bit of judgement from time to time. Even technicians like to be in charge of something -- it gives them a sense of self-worth, and a reasonably contented technician is a reasonably productive technician.


> add ingredients four, five,
>six, and seven until the mixture is homogenous.

This is not “add”, because there is nothing in the vessel before these ingredients are introduced. Again, 4 and 5 must be thoroughly mixed at the microscopic level prior to this step, in order for full performance of the product to be achieved.

The words “and mix” are missing from after the word “seven”.


>To reactor #2, add
>ingredient eight, followed by three equal volumes

Three roughly equal volumes. Whoever wrote this method was badly in need of an editor.


> of the homogenous
>mixture in reactor #1. Additionally, add ingredient nine and ten slowly,
>with constant agitation.

Sure enough, the so-called “engineer” has failed to account for the fact that a substantial fraction of the target audience will dislike or even be allergic to item 10. The batch should have been split into two roughly equal parts after the addition of item 9, and item 10 should have been added to only one of them. (Probably only half the amount specified above, in fact. ...And that amount is given incorrectly: the granularity of the objects is considerably larger than the granularity of the specification, a clear indication that the specification contains too many significant figures.)


> Care must be taken at this point in the
>reaction to control any temperature rise that may be the result of an
>exothermic reaction.

Again, the righteous engineer knows when to bring in outside expertise. Any competent consulting organic chemist could tell you that there isn’t going to be any exothermic reaction here.


>Using a screw extruder attached to a #4 nodulizer,

A real engineer knows what a spoon is, and knows how to use one!


> place the mixture
>piece-meal on a 316SS sheet (300 x 600 mm).

Overspecified. What if all available sheets are 304SS? What if they are teflon-coated aluminum? What if only 350x700mm sheets are available, or some other size? This spec should be up to the technician in any case.


> Heat in a 460K oven

This is reasonable, but perhaps overspecified. The range from 440K to 480K is probably viable. In some cases the lower end of the range may provide better product than the upper end. (...And vice versa.)


> for a
>period of time that is in agreement with Frank & Johnston’s first order
>rate expression (see JACOS, 21, 55), or until golden brown.

The term “golden brown” is unspecified. This specification should be given in meaningful terms; CIE coordinates, perhaps (X=.52 or so, Y slightly over .4), with some indication of brightness. Again, outside expertise is called for.


> Once the
>reaction is complete, place the sheet on a 25C

Overspecified again, and “c” should not be capitalized. Anything in the range of approximately 10 c to 40 c will actually do, though presumably there is a best- performance value somewhere in that range.


> heat-transfer table,
>allowing the product to come to equilibrium.

As the experienced engineer is well aware, the product is actually best before it reaches equilibrium... ...if the technician hasn’t ingested all of it before it even reaches the 300x600mm SS sheet!

...And Finally,

Engineers do write cookbooks. They’re called Cook’s Illustrated, and they are Nerd-Perfect. I kid you not: these people really got it right.

Sincerely,
The Editor (a former technician, engineer, and technical writer)



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Last modified: Tue Jun 6 14:40:47 PDT 2000