Butter Up

I have noticed a disturbing trend in the catering industry. Dinner ladies are skimping on butter (or spread).

For example, when I ask for a bacon sarnie in the canteen, it is assumed that I do not require butter (or spread) on my bun.

A bacon sandwich without butter (or spread) is a dry, disappointing travesty.

After five years of frequenting the same canteen, I have just about trained the dinner ladies to butter (or spread) my sarnie. If however, I do not properly supervise the buttering (or spreading), I end up with a stingy micron thick scraping of butter (or spread) on just one side of the sandwich. Not even enough to taste.

I have therefore decided that some sort of formula is needed for the discerning dinner lady so she can calculate of the optimum thickness of butter (or spread) to put on a given slice of bread.

Obviously, any guide should be backed up with complicated mathematics. (I should point out that before I started this process, Dr K declared off hand that the butter (or spread) should be about half a millimetre thick and that all this effort was unnecessary, however in order to support my endeavour she was happy to assist me and, afterward, eat the bread and butter).

With a little bit of help from Dr K, I came up with this formula (you can click on it for a larger version):



Complicated stuff, huh? Who'd have thought algebra would come in handy? Fortunately, quite a lot of this data is available to us.

I started by calculating the weight of the optimum amount of butter (or spread).

Here's the bread before the butter (or spread):



And here it is afterward. It's not perfectly spread, I know. I am not a trained professional!



As you can see, the difference, and therefore the weight of the butter (or spread) is 8 grams.

According to my good friend Wikipedia, the density of butter (or spread) is 0.959 grams per cubic centimetre.

The bread is 13cm long and 12cm wide.

Let's populate that formula, shall we?



So all we have to do is work out the value of X. Easy peasy!

It's just over 0.05cm, by the way. That's half a millimetre.

And let's have it in a more scientific sounding measurement: the butter (or spread) should be 500 microns thick!

So, now we know how to order a bacon butty:




(Dr K whipped the bread and butter (or spread) off the scales the moment I finished weighing them. It was gone in moments!)




UPDATE 14/10/2011: I brought up the formula and the required amount of butter (or spread) with Carol the Dinner Lady in the canteen this morning whilst ordering my bacon bun.


'You'll get what you're given,' she declared, sternly. 'And you'll be grateful.'


I did.  And I was.