0:00:03 > 0:00:06# There are lots of things All around us
0:00:06 > 0:00:10# Exciting things That surround us
0:00:10 > 0:00:12# But how does it work?
0:00:12 > 0:00:13# Do you know?
0:00:13 > 0:00:15# How it is made?
0:00:15 > 0:00:17# Do you know?
0:00:17 > 0:00:20# Things that go up Things that go down
0:00:20 > 0:00:23# Things that go pop! Things that go round
0:00:23 > 0:00:27# With special cameras To show you inside
0:00:27 > 0:00:30# It's going to be A big surprise
0:00:30 > 0:00:32# But how does it work?
0:00:32 > 0:00:34# Do you know?
0:00:34 > 0:00:35# How is it made?
0:00:35 > 0:00:37# Do you know?
0:00:37 > 0:00:38# Do you know?
0:00:38 > 0:00:40# Let's find out! #
0:00:45 > 0:00:50Hello, I'm Maddie. And today, I'm going out for a nice long walk.
0:00:50 > 0:00:53I don't know about you, but when I go on a long walk,
0:00:53 > 0:00:55I like to take a few things with me.
0:00:55 > 0:00:56What do you take?
0:00:56 > 0:00:58I've got some snacks in here.
0:00:58 > 0:01:00A juicy apple
0:01:00 > 0:01:02and a drink.
0:01:02 > 0:01:04Fizzy water. It's one of my favourites.
0:01:04 > 0:01:06PFFT!
0:01:06 > 0:01:07Oh! I love that sound.
0:01:07 > 0:01:10And did you see how all the bubbles rose to the top
0:01:10 > 0:01:15when I opened the bottle? But how do the bubbles get into the water?
0:01:15 > 0:01:19Do you know how fizzy water works?
0:01:19 > 0:01:21Let's find out.
0:01:27 > 0:01:32To show you how fizzy water is made, I've come to a fizzy water factory
0:01:32 > 0:01:38where they produce around two million bottles of water every day.
0:01:38 > 0:01:41The water is stored inside these tanks before it goes into
0:01:41 > 0:01:43the factory to get its bubbles.
0:01:43 > 0:01:46But where does the water come from?
0:01:48 > 0:01:51The water comes from this spring,
0:01:51 > 0:01:56where rainwater has collected underground for thousands of years.
0:01:56 > 0:02:01It bubbles up to the surface and it sent through pipes into the factory.
0:02:01 > 0:02:04And it's sent to something called the chiller.
0:02:04 > 0:02:08The chiller cools down the water so that it's nice and cold
0:02:08 > 0:02:10before it gets put into bottles.
0:02:10 > 0:02:13But the water inside the chiller looks like this.
0:02:13 > 0:02:17It's still, which means it doesn't have any bubbles.
0:02:17 > 0:02:20It's not fizzy like this one.
0:02:20 > 0:02:25So, how does still water become fizzy water?
0:02:28 > 0:02:30It's time for some bubbles!
0:02:32 > 0:02:36The still water is made fizzy by these two tanks.
0:02:36 > 0:02:40This tank is called a carbonation tank.
0:02:40 > 0:02:44It makes the water fizzy by pushing a gas called carbon dioxide
0:02:44 > 0:02:47into the water.
0:02:47 > 0:02:49Here's how it works.
0:02:50 > 0:02:53Water contains a gas called oxygen.
0:02:53 > 0:02:57To make the water fizzy, we need to remove the oxygen.
0:02:57 > 0:03:01Inside the tank is a metal plate with holes in it, like a sieve.
0:03:01 > 0:03:05The holes are so small that, as the water squeezes through them,
0:03:05 > 0:03:07the oxygen gas escapes.
0:03:07 > 0:03:11And it's taken away through a vent at the top of the tank.
0:03:11 > 0:03:12Bye-bye, oxygen!
0:03:12 > 0:03:14Now the oxygen is removed,
0:03:14 > 0:03:16we can make the water fizzy.
0:03:16 > 0:03:19The water, with no oxygen in it,
0:03:19 > 0:03:22is sent to the second big tank.
0:03:22 > 0:03:28Here, carbon dioxide gas is pushed into the water very, very fast.
0:03:28 > 0:03:32As more and more carbon dioxide bubbles fill the tank of water,
0:03:32 > 0:03:34pressure builds up.
0:03:34 > 0:03:38This makes the bubbles dissolve into the water
0:03:38 > 0:03:40so that we can't see them any more.
0:03:40 > 0:03:43And now, the water is fizzy.
0:03:43 > 0:03:46The pressure is like a balloon ready to burst,
0:03:46 > 0:03:50and it stays like this as the water is put into bottles.
0:03:50 > 0:03:54We only see the bubbles again when the bottle is opened.
0:03:54 > 0:03:55The pressure is released,
0:03:55 > 0:03:57we hear a big fizzing sound,
0:03:57 > 0:04:00and the bubbles rush to the surface.
0:04:00 > 0:04:02Clever, isn't it?
0:04:02 > 0:04:03Let's use my special camera
0:04:03 > 0:04:07to get a closer look at the carbonation tanks.
0:04:07 > 0:04:12So, the cold, still water comes in from the chiller,
0:04:12 > 0:04:15through the pipe, and into this first tank.
0:04:15 > 0:04:20And inside here, all of the oxygen is sieved out.
0:04:20 > 0:04:23And then it goes into this second tank,
0:04:23 > 0:04:26and in the second tank the water gets its bubbles.
0:04:26 > 0:04:28The carbon dioxide goes in
0:04:28 > 0:04:31through this pipe just here,
0:04:31 > 0:04:34and it's squeezed and squeezed into the water until all of the
0:04:34 > 0:04:38bubbles dissolve, and then, when it's fizzy,
0:04:38 > 0:04:40the water comes out of the tank,
0:04:40 > 0:04:44goes through this pipe, off to get put into bottles.
0:04:48 > 0:04:52And this is where the bottles are filled with water.
0:04:52 > 0:04:56Look how fast the bottles fill up with the water!
0:04:59 > 0:05:03So this is a finished bottle of fizzy water.
0:05:03 > 0:05:07I can't see any bubbles, can you? Shall we let the bubbles out?
0:05:07 > 0:05:09PFFFFT!
0:05:09 > 0:05:12Oh! Ha-ha! 'Did you hear that? Let's hear it again.'
0:05:12 > 0:05:14PFFFFT!
0:05:14 > 0:05:16'What a brilliant hissing sound.'
0:05:16 > 0:05:19As I undid the lid all of the gas was released,
0:05:19 > 0:05:21and they bubbled up to the top.
0:05:21 > 0:05:27Let's use my special camera to slow things down and watch it again.
0:05:27 > 0:05:30This camera films in slow motion, which means that when I
0:05:30 > 0:05:34open the bottle, the bubbles of gas will be released and we can see it
0:05:34 > 0:05:37happening really slowly.
0:05:37 > 0:05:40So, let's press record.
0:05:40 > 0:05:42Are you ready?
0:05:43 > 0:05:47Can you see there are no bubbles until I open the bottle.
0:05:47 > 0:05:52And then thousands of tiny bubbles rush to the surface.
0:05:52 > 0:05:54Now THAT was brilliant.
0:05:54 > 0:05:57All of those little bubbles, you can still see them,
0:05:57 > 0:06:01those bubbles of carbon dioxide gas were just waiting to be released,
0:06:01 > 0:06:06and as soon as I undid the lid, they certainly were!
0:06:06 > 0:06:07They're still going!
0:06:09 > 0:06:14What was your favourite bit about seeing how fizzy water works?
0:06:14 > 0:06:18Do you remember the name of the gas that makes the water fizzy?
0:06:18 > 0:06:21That's right - it's called carbon dioxide.
0:06:21 > 0:06:25Did you hear the sound the bottle made when I opened it?
0:06:25 > 0:06:26PFFFFT!
0:06:26 > 0:06:28Oh! Ha-ha!
0:06:28 > 0:06:31And did you see the way the bubbles go up inside the bottle
0:06:31 > 0:06:34when I used my special camera?
0:06:39 > 0:06:42So, the next time you have some fizzy water, you'll know how the
0:06:42 > 0:06:48bubbles got inside and how they stay hidden until you open the bottle.
0:06:48 > 0:06:52Now, it's time for a snack. Ooh - I could have a yoghurt.
0:07:00 > 0:07:03Yum. Strawberry yoghurt.
0:07:03 > 0:07:06I like yoghurt. Do you?
0:07:06 > 0:07:10But, do you know how yoghurt is made?
0:07:10 > 0:07:12Where does yoghurt come from?
0:07:12 > 0:07:14Let's find out.
0:07:20 > 0:07:25The first things we need to make our yoghurt are just in here.
0:07:27 > 0:07:30Lots and lots of cows.
0:07:37 > 0:07:40All yoghurt is made from milk, but the yoghurt we're going
0:07:40 > 0:07:44to see being made today comes from cows' milk.
0:07:44 > 0:07:47So, to see yoghurt being made, first, we need some milk.
0:07:56 > 0:07:58All these cows are about to be milked,
0:07:58 > 0:08:01which means their milk is collected from their udders.
0:08:01 > 0:08:06And you can see their udders underneath the cows.
0:08:06 > 0:08:08Can you see Rich, the herdsman?
0:08:08 > 0:08:11He's attaching a special pipe to the cows' udders.
0:08:14 > 0:08:16This is called a cluster,
0:08:16 > 0:08:20and it gently sucks the milk from the cows udders and takes it
0:08:20 > 0:08:24down this pipe to this plastic tub called a milk meter,
0:08:24 > 0:08:28which measures the amount of milk the cow produces.
0:08:37 > 0:08:41And once they're finished milking, the clusters just fall off
0:08:41 > 0:08:43and the cows head back to the barn.
0:08:43 > 0:08:46Mooooo!
0:08:46 > 0:08:50In one day, a single cow can make 21 pints of milk.
0:08:50 > 0:08:53That's 21 of these.
0:08:53 > 0:08:57That's enough for 70 bowls of cereal.
0:08:57 > 0:09:00But how does milk turn into yoghurt?
0:09:05 > 0:09:09Once the milk has been collected, it's taken to the factory in
0:09:09 > 0:09:13a lorry and stored in huge tanks called milk silos.
0:09:13 > 0:09:17The milk is then taken from the silos into the factory to be
0:09:17 > 0:09:18made into yoghurt.
0:09:18 > 0:09:22The first stage is for all the ingredients to get mixed together.
0:09:22 > 0:09:25And that happens here, in the mixing room.
0:09:25 > 0:09:29Yoghurt is made from milk, cream, some milk powder,
0:09:29 > 0:09:30and a bit of sugar.
0:09:30 > 0:09:33And once they're mixed together, they get sent on to the
0:09:33 > 0:09:35next part of the factory.
0:09:35 > 0:09:39The next stage happens in here, and it's very noisy.
0:09:40 > 0:09:42MACHINES WHOOSH AND WHIR
0:09:42 > 0:09:45Look at all those pipes.
0:09:45 > 0:09:49All the ingredients that have now been mixed together are heated up.
0:09:49 > 0:09:51This is called pasteurisation,
0:09:51 > 0:09:55and it gets rid of any bad bacteria that could be in the milk.
0:09:55 > 0:09:58Once it's reached the right temperature,
0:09:58 > 0:10:01the pasteurised mixture is moved into one of these.
0:10:01 > 0:10:04They're called incubation tanks,
0:10:04 > 0:10:06and they are huge.
0:10:06 > 0:10:09Now a special ingredient is added.
0:10:09 > 0:10:13And it will turn the milky mixture into yoghurt.
0:10:14 > 0:10:18The special ingredient is called a starter culture,
0:10:18 > 0:10:22and it's made of a mix of good bacteria.
0:10:27 > 0:10:31Bacteria has to be kept in the freezer, because as soon as
0:10:31 > 0:10:36it gets warm and is put in the incubator, it starts to multiply.
0:10:36 > 0:10:38The starter culture is added to the yoghurt
0:10:38 > 0:10:41and then left to get to work.
0:10:41 > 0:10:44And when it's added to the milky mixture inside this
0:10:44 > 0:10:48incubation tank, it starts to multiply.
0:10:48 > 0:10:50This means that two good bacteria
0:10:50 > 0:10:52become four, four become eight,
0:10:52 > 0:10:55and eight become 16, and so on,
0:10:55 > 0:10:57until you have lots of good bacteria
0:10:57 > 0:10:59mixed in with the milk.
0:10:59 > 0:11:03Inside this incubator, the yoghurt has already been mixed,
0:11:03 > 0:11:06so lets use my special camera to take a look.
0:11:06 > 0:11:10Whoa! It's so thick and creamy.
0:11:10 > 0:11:14All of that good bacteria has multiplied and multiplied,
0:11:14 > 0:11:17which has made everything really thick.
0:11:17 > 0:11:19It's turned it into yoghurt.
0:11:21 > 0:11:26The yoghurt is cooled down to stop the bacteria multiplying any more.
0:11:26 > 0:11:28And it's piped to a smaller tank.
0:11:28 > 0:11:33This is plain, natural yoghurt, and it's lovely on its own.
0:11:33 > 0:11:38It's great for cooking, you might have even had it on muesli at home.
0:11:38 > 0:11:42But sometimes it's nice to add a bit of flavour.
0:11:42 > 0:11:44What flavour yoghurt do you like?
0:11:44 > 0:11:46Do you like peach?
0:11:46 > 0:11:47Blackcurrant?
0:11:47 > 0:11:51Let's see what flavour this yoghurt's going to be.
0:11:51 > 0:11:53This is strawberry puree,
0:11:53 > 0:11:57and it's going to turn the plain yoghurt into strawberry yoghurt.
0:11:57 > 0:11:59My favourite.
0:12:01 > 0:12:05The mixer turns the yoghurt and fruit puree into
0:12:05 > 0:12:07a lovely pink colour.
0:12:07 > 0:12:10It's now time for the drop test.
0:12:10 > 0:12:12And this is where the team check
0:12:12 > 0:12:14that the yoghurt is the right thickness.
0:12:14 > 0:12:18If the yoghurt is thick enough, it's ready to go into pots.
0:12:18 > 0:12:23The machine works so quickly. One dollop of yoghurt in every pot.
0:12:23 > 0:12:25And look how many pots there are.
0:12:29 > 0:12:35This factory could make over a million pots of yoghurt a day.
0:12:39 > 0:12:43I love the sound of the lids being glued down onto the pots.
0:12:45 > 0:12:49It sounds like a train going over tracks.
0:12:49 > 0:12:52CLACKETY-CLACK! CLACKETY-CLACK!
0:12:57 > 0:13:00And here we go, a finished pack of yoghurt.
0:13:00 > 0:13:04Just like you'd see in the shops, or maybe even in the fridge at home.
0:13:04 > 0:13:09What was your favourite part about seeing how yoghurt was made?
0:13:09 > 0:13:13Do you remember what part of the cow the milk comes from?
0:13:13 > 0:13:15That's right - it's the udder.
0:13:16 > 0:13:20Did you hear the sound of the lids being pressed onto the pots?
0:13:20 > 0:13:23CLACKETY-CLACK! CLACKETY-CLACK!
0:13:23 > 0:13:27And did you see how the bacteria thickened the yoghurt?
0:13:35 > 0:13:38So, the next time you tuck into a tasty yoghurt,
0:13:38 > 0:13:43you'll know that it started out as milk that came from a cow.
0:13:43 > 0:13:45Thank you, cows!
0:13:45 > 0:13:48And, now you know how the bubbles get into fizzy water.
0:13:48 > 0:13:50I'll see you next time.
0:13:52 > 0:13:56# There are lots of things All around us
0:13:56 > 0:13:59# Exciting things That surround us
0:13:59 > 0:14:01# But how does it work?
0:14:01 > 0:14:03# Do you know?
0:14:03 > 0:14:05# How is it made?
0:14:05 > 0:14:06# Do you know?
0:14:06 > 0:14:08# Do you know?
0:14:08 > 0:14:10# Let's find out! #