Friday, April 16, 2010

Question of the Week: How many strawberries are in a box of cereal?

 "panning for gold" method of seperation
So I had a heated "discussion" with a good friend of mine the other day, the subject in question being how many strawberries are actually in a box of cereal featuring dried strawberries? In my limited experience, it's always been abysmally few pieces and so I told her i'd bet that there weren't more than 3 whole strawberries in a single box. She claimed her Kellog's Special K with Strawberries had way more than that (she also thot i meant strawberry pieces). So we made a bet! $10 to see who's right!

Being the thorough scientist (and apparently having nothing better to do) i went and bought a box to count the number of strawberries in it. I poured my first bowl and used the proper extraction tool (chopsticks) to remove the strawberry pieces. Hmmm...more than i thought, Special K definitely has more strawberry pieces than your typical strawberry-enhanced cereals. However, it turns out the concentration of strawberry pieces is higher on the top for some reason.

So how do we count how many strawberries are in it? You can't really count the pieces cause they're all different sizes and you can't compare volumes cause freeze-drying shrinks the fruit. The scientific method? by comparing Mass!

average weight of strawberry 23.573382g.

To make the result more applicable, i found the average weight of locally-available strawberries which were washed, salad-spun dried, and stem removed as if you would prepare them to eat with cereal. It was 528g for 14 strawberries = 37.714g each. They were rather large.

Strawberries are 91.67% water, meaning 8.3% other stuff.
Freeze-dry process typically leaves 1-4% water in the food product.

weight of 3 whole strawberries x (stuff%+water%) = weight of 3 freeze-dried strawberries (g)
113.14g   x   8.3%+1%  =   10.560g
113.14g   x   8.3%+2%  =   11.691g
113.14g   x   8.3%+3%  =   12.823g
113.14g   x   8.3%+4%  =   13.954g

So if the weight turns out lower than 10.56g then, there is definitely less than 3 strawberries. If the weight is greater than 13.95g then there is definitely more than 3 strawberries. Somewhere in the middle, means we can't tell for sure (and neither of us wins the bet).

Completely seperated from the cereal, i weighed the strawberries on a precision digital scale (in a university lab), taring for the ziplock bag weight of course!   Hmmm 18.4g, definitely more than 3 strawberries!

Note, once you open the bag, it's more accurate to remove all the strawberries in one go, cause they will start absorbing moisture from the air.  I used a ziplock freezer bag, the thicker plastic makes them gas-impermeable.

Conclusion: one box of Kellog's Special K with Strawberries cereal contains 4-5 whole strawberries (or 6-8 average strawberries). I guess that's not bad, but it's not a whole lot either. I think you're still always better off buying a container of strawberries and adding 2-3 to your bowl. But now you can calculate exactly how many strawberries there are and knowing is half the battle! maybe i should go out and purchase other brands of cereal just to see how many strawberries are in them for comparison...

Friday, April 9, 2010

DIY Figurine Display Case

I needed an acrylic display box for my anime figurines and i thot it would be cheaper to make my own.

What you'll need:
* 11x17" acrylic sheet (2) $3.57 x2 = $7.14
* sharp razor blade/knife
* metal straight edge (ruler)
* self-healing mat
* Legos

I bought a plastic sheet cutter ($3) but it turns out it was nothing special and a razor blade knife would've done the same job. Just make sure it's sharp and has a nice handle. So really the cost is only the acrylic sheets since the other stuff i already had.

I decided to split the sheet right down the middle for a box height of 5.5" and make a width of 4" for the side pieces (length 17-4 = 13"). In retrospect, it would've been easier to make both the box height and width 5.5" because then the front/back and top/bottom would be the same size and there would be less cuts to make. It's pretty easy to cut acrylic sheets, basically you score a line and then break the sheet across a hard edge.

I needed a frame to make sure my walls were 90 degree angles from each other and the table, so i borrowed a trick from casting plaster and used Legos to build an inner and outer brace to align each corner. A bead of hot glue along the outer edge. Repeat x3 more times for each corner. The 4 walls should be fairly free-standing now. Then I hot-glued the outer edges that were previously covered by the Lego frame. Use a spot of hot glue for each inner corner to secure the top to the sides of the box. Done! (the bottom piece doesn't need to be glued to the box).
I'll probably use some brush-on Crazy glue (cyano-acetate glue) to fill in the cracks between the top and sides if i want to make it air-tight.

Is this worth doing? Well, if you can find your display box for $8 or less, you might as well buy it. Otherwise, the DIY approach lets you customize the box size and it's actually pretty easy to do.

Tuesday, April 6, 2010

Question of the week: Can you cook soup forever?

A quick google-search did not reveal the answer, thus i posit the question here:

A question came up while making chilli with my crockpot. Generally, the longer you leave it on, the better the soup tastes. Can i leave it on forever (assuming adding some water every once in a while to maintain the soup)? When will it "go bad?" if ever?

It can only really go back by two mechanisms:

1. bacterial/mold - what usually degrades old food. But in this case the simmering temperature would keep any organism from growing, unless you live near oceanic volcano vents which has high-temperature bacteria. So let's assume you'll never have degradation from bacteria.

2. chemical change due to temperature/agitation. Eventually, one would expect all the beans and chunks to break apart and dissolve into the soup. Possibly, with the continual heat entry there may be chemical changes to the nutrients, possibly creating toxins? Or maybe the meat would get old and tough? But if you can simmer for 6 hours with no significant change, what the chance what you'll get significant change over 24 hours? or days or weeks?

Science in action: to solve these questions, i propose an experiment! I will cook chili continuously for a month in my crockpot, then have taste-testers try out the soup. Because i would be biased if i tried it myself, i have to invite some friends over to try it out, telling them that it's a fresh-batch of Chili to see if they detect any fault in the soup. I would repeat once a week to see if any change occurs over 4 weeks and the initial taste.

Comments/suggestions welcome!