Millilitres

[kenny1234]

I have always believed that a teaspoon was 5 mls----I have just put 20 of them into a measuring jug and it only reads 50 mls rather than 100mls? Anyone have an explanation?

[Fitzer]

A measuring teaspoon is 5 ml, however something one regards as a ‘normal’ teaspoon may well not be.

[aelmpvw]

must have been a very small teaspoon . . .

[calmck]

Teaspoons come in different sizes.

[gingejbee]

Rather than putting into a measuring jug (not the best way of measuring a small volume) - weigh them on a digital kitchen scales.
Grams equals ml. That's the way I always measure smallish volumes...must be my scientific background!

[youngmafbog]

Yes, I do as Ginge says. I have a set of small 'druggie' scales for my fertiliser etc.

In answer to the OP, its as the first post says. A teaspoon is not necessarily a teaspoon. It's just something to stir your tea.

[Electrochem]

Ref grams equals ml. That only applies to pure water at 20C. You have to take into account the relative density of the liquid. Certainly wouldn't work for golden syrup! I spent the vast majority of my working life working in R and D Labs and a lot of my time was taken up with calibration. As an example, pure honey has a relative density (used to be referred to as specific gravity) of 1.42g/cm3 (cm3 = ml). Formula rho (RD) = m/v where m = mass and v = volume. We have a variety of teaspoons, and they all have different capacities. As has been said, the best thing to use would be measuring spoons.

[theprof]

Absolutely right Electrochem.

Isopentane (or 2-methylbutane as it's known nowadays) will spectacularly prove that grams don't equal millilitres. It makes a brilliant lab demonstration for the unconverted using the right equipment.

[davebro]

try heaped teaspoons!

[gingejbee]

Yes, electrochem, I knew somebody would come along with that . I was expecting a modicum of common sense...and the OP was about water.

[theprof]

Gingejbee, the reality of all this when measuring water is the point that no two teaspoons contains the exactly the same ml of water unless the teaspoons are identical. It follows that the weight will differ. The OP's teaspoons are very likely to differ in their capacity to what you or I have at home as others implied earlier. You cannot rely on 5g being 5ml.

In the USA a teaspoon is said to be 4.92ml. Problem is that the Americans have never been very good at adopting standard measures and from personal experience I can tell you the size varies just like the UK despite what Google will tell you.

In the Sixties when most of the country were going over to metrication, the instructions on medicine bottles said to take a "5 ml spoonful OR 1 teaspoon" of the medicine. It took a few years for the medical profession to realise the two were not the same, which led to them popping a plastic 5ml spoon into every carton of liquid medicine. No one at the time had a means of measuring 5ml accurately and yes, it sometimes made a difference both therapeutically and to the number of doses in the bottle.

[Electrochem]

@gingejbee 12:33 "I knew someone would come along with that" You weren't disappointed then.

"the OP was about water" No reference to water in the original post.

[gingejbee]

the prof...yes, I know all that - I spent my working life in and around analytical laboratories. The OP mentioned teaspoons and measuring jugs...not micro-analytical techniques.
When answering a simple question, I try to keep the answer simple.
I feel that too much scientific detail in the answer smacks of "showing off".

[Sqad]

////I feel that too much scientific detail in the answer smacks of "showing off"////

Well said gingejbee.........that has been my thoughts on many threads on AB for a decade or more.

[pastafreak]

Are designated, made for cooking and baking, measuring spoons likely to be far off?

[theprof]

Oerr, well that's telling me then. Right, so let's simplify it:

One teaspoonful is not 5ml therefore one teaspoonful cannot weigh the same as 5ml.

[gingejbee]

^Quite...which is why I suggested the OP puts his 20 spoonsful on a digital scale, weighs it and finds what 1 spoon holds in grams and hence the volume of that spoon in ml...assuming water is used, and not some strange organic liquid, of course.

[bobbinwales]

Were you doing this as an experiment to check the capacity of a teaspoon? or was you simply trying to get a specific volume as I'm not sure why you'd use a teaspoon if you needed to measure out 500ml?

[douglas9401]

"Are designated, made for cooking and baking, measuring spoons likely to be far off?"

I suppose it's all about where you're standing at any given time, like Dougal's cows.

[douglas9401]

Just trying to put a buffer between the cast of The Big Bang Theory. :-)

[Khandro]

1,000 grams (1 litre) of water weigh one kilogram, do the maths.