Q for the Science Geeks...

amother

Mon, Apr 12 2021, 12:46 pm

Me and dh have a long running argument. It goes like this:

When you make iced coffee, he likes to first put in the ice cubes in the hot water to cool the hot water than add milk.

I say, that it'll get cooler with less ice cubes if you first add milk to cool the hot water mixture, and then add the ice cubes to that cooled mixture because with his way the ice cubes melt immediately.

He claims his way cools it better and faster with less ice cubes. (Hey, we should've just done an experiment... oh well.. easier to argue right?)

Which is it?
Or are they the same?

Got such q's... post them in this thread! We'll have the science geeks answer.

watergirl

Mon, Apr 12 2021, 12:48 pm

I make the coffee in one cup and I have ice in another cup. I pour in some milk to the ice, then add the coffee, then more milk on top of that. It's perfect. It also helps that I use my nespresso which does not make the coffee scalding hot in the first place.

amother

Mon, Apr 12 2021, 12:56 pm

On that note.. we also used to disagree on this one:

If you place soda in the door of the fridge (gets shaken each time you open and close the fridge door, thus losing gas) will it lose more gas then if you place it sideways on the shelf in the fridge? (which requires turning it up and down when removing and replacing = losing gas... and also it has more surface area to lose gas when it's laying horizontally)

I forgot why we stopped arguing about that one lol... we just keep it lying down. Got no room for vertical on the shelves for those tall Coke bottles.

But curious if there's an answer to this one.

sequoia

Mon, Apr 12 2021, 1:29 pm

naturalmom5 wrote:

If a bear makes a loud noise in the noise in the woods is it really a sound if no one is there to hear it

Inquiring minds want to know

Why are you like this?

Seriously. What’s wrong with this thread? In your “professional” opinion.

leah233

Mon, Apr 12 2021, 1:35 pm

amother [ OP ] wrote:

I think he is right. Heat is a measure of molecular activity: the faster a thing's molecules move the hotter it becomes

Does the water heat up the ice cubes or do the ice cubes cool off the water?

Answer is neither. The ice cubes absorb heat from the water. By doing so the water loses some of it's heat. The energy of the water's heat flows to the ice cubes.

That being the case the larger the friction between the two forces the more and quicker of an impact they should have.

Genius

Mon, Apr 12 2021, 1:37 pm

The way to figure out the answer is to create an hypothesis. (In the case of the ice cubes, you have differing hypotheses) then experiment, observe, and come to a conclusion. My hypothesis is that the outcome will be the same regardless of the order in which the ingredients were placed in the cup, because the thermal energy is equal (the amount of hot molecules that need to be cooled is the same, order doesn’t change that.)
Feel free to experiment and prove me wrong.

amother

Gray

Mon, Apr 12 2021, 1:47 pm

Genius wrote:

The only variable here is time and space, liquid will cool off naturally over time (assuming the room is of average temperature 70° f) and how much of the liquid is "touching" the air, causing it to lose heat faster...
I don't remember the exact details from science class but those might make a difference.

amother

Yellow

Mon, Apr 12 2021, 1:55 pm

I have no clue about heat and molecules and liquid but when I make iced coffee I dissolve instant coffee in a little bit of hot water and then add milk and then add ice at the end.

If you add ice to the hot water/coffee, you can easily end up with pieces of instant coffee that don't get dissolved. That is less delicious and therefore an inferior method to making iced coffee. Very Happy

amother

Gray

Mon, Apr 12 2021, 2:00 pm

amother [ Yellow ] wrote:

You can also wait until the coffee is completely dissolved 🤷🏻‍♀️

amother

Mon, Apr 12 2021, 2:10 pm

amother [ Yellow ] wrote:

no, don't worry my husband is very makpid on mixing the coffee, sugar and water thoroughly prior to adding anything. He used to freak out at all the pieces in my coffee and iced coffee... like how could I???? Ha ha.

amother

Mon, Apr 12 2021, 2:12 pm

amother [ Gray ] wrote:

I guess to really prove one or the other we'd need to put in equal amounts of ice cubes and milk in each one and then using a thermometer measure which is cooler. Ok one day...

amother

Mon, Apr 12 2021, 2:15 pm

leah233 wrote:

thanks..
but in the case of putting in the milk first you are cooling off the entire liquid and then when you put in the ice it has less heat to absorb... ok, I don't even know exactly what I'm saying

amother

Mon, Apr 12 2021, 2:17 pm

watergirl wrote:

that's a neat idea! I wonder if in terms of science and stuff mixing the milk with the ice first and then pouring into the hot mixture makes a difference in being able to use less amount of ice - and getting a colder mixture.

amother

Mon, Apr 12 2021, 2:18 pm

Genius wrote:

that hypothesis does make sense...

Malkqueen

Mon, Apr 12 2021, 2:19 pm

Actually, your DH may be right about adding the ice cubes first.

Heat runs around trying to warm everything up. Cold just stays where it is. Meaning that the ice melts because the hot water is trying to warm it up, so to speak. However, it's countering a strong force (ice cubes!), so it loses all of its heat before it can effectively melt the cubes. So you have dark coffee with cubes, all very cold, which you then add cold milk to, making a nice iced coffee.

If you add milk first, then the hot water has a less powerful contender, so to speak, and as a result it can warm up the milk somewhat, bringing the whole drink to a cool, but not freezing temperature. Then the ice would come along, causing the cool milk to attempt to warm *that* up. However, because the coldness of the cubes isn't traveling outward to the milk, but instead melting at a very very slow pace, the actual liquid of the ice coffee won't be as cold as the other method.

cbsp

Mon, Apr 12 2021, 2:20 pm

amother [ OP ] wrote:

Please introduce him to cold brew!