0:00:02 > 0:00:04This series is about all the stuff we can't live without.
0:00:04 > 0:00:08Whether it's products for personal hygiene, home cleaning or even DIY.
0:00:08 > 0:00:12It's about those bottles, cans, sprays, jars and tubes
0:00:12 > 0:00:15crammed into our cupboards, drawers, handbags, sheds and cars.
0:00:15 > 0:00:20I want to know, what's in all this stuff?
0:00:21 > 0:00:25'I'm Jane Moore and I've been handed the ultimate dream ticket -
0:00:25 > 0:00:31'the chance to pull apart some of the most essential items on my everyday shopping list
0:00:31 > 0:00:35'and zero on precisely what's in them that makes them work.'
0:00:35 > 0:00:37We're just in a flush cycle now.
0:00:37 > 0:00:40'It's a mission that's set to take me right out of my comfort zone.'
0:00:40 > 0:00:42Oh, God! I can't bear it.
0:00:42 > 0:00:48'One which demands that I get intimate with an army of boffins and some mind-blowing science.'
0:00:48 > 0:00:50Well, that worked(!)
0:00:50 > 0:00:52'I might've bunked off chemistry at school,
0:00:52 > 0:00:56'but I know I can trust my nose when it comes to sniffing out the facts.'
0:00:56 > 0:00:58I'm going to retch.
0:00:58 > 0:01:01'Yes, I'm hunting for the wonderstuff
0:01:01 > 0:01:03'that holds our lives together.'
0:01:20 > 0:01:23'This time, I fling open the bathroom cabinet
0:01:23 > 0:01:28'to find the wonderstuffs we all rely on to stay preened and cleaned.'
0:01:28 > 0:01:32There are four things in what supermarkets call the "personal care aisle"
0:01:32 > 0:01:34that I buy more than anything else.
0:01:34 > 0:01:38That's soap, shampoo, conditioner and toothpaste.
0:01:38 > 0:01:40My challenge is to go behind the labels
0:01:40 > 0:01:44and discover the magic ingredients that keep us clean.
0:01:44 > 0:01:50Later on in the programme, I'll get my hands on the wonderstuffs at the heart of hair conditioner.
0:01:50 > 0:01:54As peaks go, it's like a molehill up against Mount Everest.
0:01:54 > 0:01:55Absolutely.
0:01:55 > 0:01:56And toothpaste.
0:01:56 > 0:01:58It doesn't have much foaming action.
0:01:58 > 0:02:00It has no foaming action.
0:02:00 > 0:02:02It has gravel action is what it has.
0:02:02 > 0:02:05But before all that, I want to get the low-down
0:02:05 > 0:02:09on what has to be the ultimate bathroom essential - soap.
0:02:13 > 0:02:18As a nation, we use over 100,000 metric tons of soap every year.
0:02:18 > 0:02:22The story of what makes it so good at getting us clean
0:02:22 > 0:02:25will take me back 5,000 years.
0:02:25 > 0:02:28My new best friend, material scientist Dr Mark Miodownik,
0:02:28 > 0:02:34reckons he can show me what makes soap so hard to beat when it comes to personal hygiene,
0:02:34 > 0:02:39by creating some much as our ancestors knew it.
0:02:39 > 0:02:42We'll have a go at cooking up some soap, made to the original recipe.
0:02:42 > 0:02:46Hi, Mark. Just a hotdog for me, thanks.
0:02:46 > 0:02:48We'll eat later.
0:02:48 > 0:02:51I thought first we could try and make soap the old-fashioned way.
0:02:51 > 0:02:55The way it's been made for thousands of years before the modern era.
0:02:55 > 0:02:58Mark is going to conjure up soap from two ingredients
0:02:58 > 0:03:02that would've been a basic part of life for our ancestors.
0:03:02 > 0:03:06So we're going to take fat, which is just normal fat, lard,
0:03:06 > 0:03:11and we're going to add an alkali to it, which we'll make from wood ash.
0:03:11 > 0:03:13This is something that our ancestors really valued.
0:03:13 > 0:03:17It was very important for their crops but also, it turns out, to make soap.
0:03:17 > 0:03:19How do you think they discovered this?
0:03:19 > 0:03:22It's been around for 5,000 years.
0:03:22 > 0:03:26It was probably because people were roasting meat over the fire
0:03:26 > 0:03:28and it was dripping down, the fat, from the meat
0:03:28 > 0:03:30and mixing with the ashes and making soap.
0:03:30 > 0:03:34- People must've picked it out of the fire the next day and thought... - "I'll do this!"
0:03:34 > 0:03:37In fact, the word alkali is the Arabic for "from ashes".
0:03:37 > 0:03:40Let's see if Mark can recreate
0:03:40 > 0:03:44this most fundamental of chemistry miracles.
0:03:44 > 0:03:49The ashes Mark has collected from the fire are added to water
0:03:49 > 0:03:51to create something called caustic hot ash,
0:03:51 > 0:03:55a strong alkali at the other end of the pH scale to an acid...
0:03:55 > 0:03:56he tells me.
0:03:56 > 0:03:59What we're doing is getting the liquid, the water,
0:03:59 > 0:04:03to dissolve out the active ingredient in here.
0:04:03 > 0:04:05It'll dissolve into the water
0:04:05 > 0:04:08and in a minute, we'll see it clearing
0:04:08 > 0:04:10and there'll be this brownish, muckish water,
0:04:10 > 0:04:12which is exactly perfect.
0:04:12 > 0:04:15- There we are. Nicely plunged.- Yes.
0:04:15 > 0:04:17I'll show you something from your past,
0:04:17 > 0:04:19which will probably make you fearful.
0:04:19 > 0:04:21It's not one of my ex-boyfriends, is it?
0:04:21 > 0:04:24It's worse! It's litmus paper!
0:04:24 > 0:04:26From your chemistry lessons of old.
0:04:26 > 0:04:30Do you remember how to tell if something is acidic or alkali?
0:04:30 > 0:04:33It goes blue if it's an alkali, red if it's an acid.
0:04:33 > 0:04:37If this is an alkali, this piece of paper should go blue.
0:04:37 > 0:04:39That's properly blue.
0:04:39 > 0:04:42That is victory for us and for our ancestors.
0:04:42 > 0:04:45That means if we take that liquid and add it to some fat,
0:04:45 > 0:04:46we're going to get soap.
0:04:49 > 0:04:53Our pot ash solution is very dilute
0:04:53 > 0:04:56so we need to boil it on the hob to make the alkali more concentrated.
0:05:00 > 0:05:03'Next step is to melt down the fat.
0:05:03 > 0:05:06'It's nothing more complicated than good, old lard.'
0:05:06 > 0:05:08I feel like Delia Smith.
0:05:08 > 0:05:12'Our pot ash soup is now a nice, dark brown gunk,
0:05:12 > 0:05:15'ready to go into the melted fat.
0:05:15 > 0:05:19'Personally, I'll be amazed if we can make soap from this.'
0:05:19 > 0:05:21Enter the alkali!
0:05:21 > 0:05:24'This is what's known in the trade as saponification,
0:05:24 > 0:05:27'literally soap-making.
0:05:27 > 0:05:29'Something's definitely happening.'
0:05:29 > 0:05:31It looks like an atomic cloud.
0:05:31 > 0:05:34We've made a reaction between the fat and the alkali.
0:05:34 > 0:05:36- Can you see what's happening?- Yeah.
0:05:36 > 0:05:37That is soap.
0:05:37 > 0:05:39Ah!
0:05:39 > 0:05:40Can you see the suds?
0:05:40 > 0:05:41Yeah.
0:05:41 > 0:05:44'This raw soap is caustic enough to strip paint.
0:05:44 > 0:05:48'We should now leave it for a day to become solid and safe to handle.
0:05:48 > 0:05:50'But we're in a hurry to see if it works.'
0:05:50 > 0:05:55We're going to have a go at some of these everyday muck stains
0:05:55 > 0:06:00that we all know about - chocolate spread, lipstick and shoe polish.
0:06:00 > 0:06:02So, here we go.
0:06:02 > 0:06:06I'll use the home-made soap. Mark will just use water.
0:06:06 > 0:06:09The gloves are just in case there's left-over alkali
0:06:09 > 0:06:11which could burn our skin.
0:06:12 > 0:06:17If we've managed to make proper soap, it should be able to break down stains,
0:06:17 > 0:06:22disperse them in water and leave the glove clean.
0:06:23 > 0:06:27Well, the lipstick is coming off far more easily
0:06:27 > 0:06:29than yours appears to be doing.
0:06:29 > 0:06:31I'm just spreading the lipstick all over me.
0:06:31 > 0:06:33Yeah. Mine's...
0:06:33 > 0:06:36Oh, wow! You've done very well there.
0:06:36 > 0:06:38Let's compare.
0:06:38 > 0:06:40Victory is mine.
0:06:40 > 0:06:44Look, that is, that has come off pretty much completely
0:06:44 > 0:06:47and that is a disaster area.
0:06:47 > 0:06:50Our ancient soap recipe works a treat.
0:06:50 > 0:06:55Made simply from fat and alkali, the chemical reaction between the two
0:06:55 > 0:06:59produces a new substance that will clean away dirt.
0:06:59 > 0:07:02And there's little difference between our home-made effort
0:07:02 > 0:07:05and the more refined soaps we pick off the shelves.
0:07:05 > 0:07:10Over ten million UK homes still use bars of soap
0:07:10 > 0:07:15and most of it starts life as this stuff - soap noodles.
0:07:15 > 0:07:18The basic recipe of fat plus alkali is the same,
0:07:18 > 0:07:22except animal fat is usually swapped for vegetable fats like palm oil.
0:07:22 > 0:07:26Add colour and perfume and you have modern soap.
0:07:29 > 0:07:32Having stripped soap back to its basic components,
0:07:32 > 0:07:37I definitely feel as though I've discovered the original cleaning wonderstuff.
0:07:37 > 0:07:41The recipe might be thousands of years old, but you could argue
0:07:41 > 0:07:45that this magical substance is still the bedrock of modern hygiene.
0:07:49 > 0:07:53'Like a lot of people, I don't buy as many bars of soap as I used to,
0:07:53 > 0:07:57'opting for liquid hand wash and shower gel instead,
0:07:57 > 0:08:00'and I suddenly spot a recurring theme on the labels.'
0:08:00 > 0:08:03Sodium laureth sulphate.
0:08:04 > 0:08:06Sodium laureth sulphate.
0:08:08 > 0:08:09Sodium laureth sulphate.
0:08:09 > 0:08:13Seems like it's not soap itself I've been using but something called,
0:08:13 > 0:08:16you've guessed it, sodium laureth sulphate.
0:08:16 > 0:08:20Check this out - it's also in these shampoos, both basic and posh,
0:08:20 > 0:08:24so it looks like I've been putting it on my hair all these years too.
0:08:24 > 0:08:28But what on earth is this stuff? And where does it come from?
0:08:28 > 0:08:30Is it doing something that good old soap can't?
0:08:30 > 0:08:34Time to look inside one of the most crucial bottles of all
0:08:34 > 0:08:38when it comes to our daily ablutions - shampoo.
0:08:41 > 0:08:44'To find out, I've been invited onto the shop floor of a factory
0:08:44 > 0:08:48'that makes shampoo for supermarket own brands.
0:08:48 > 0:08:54'That must be why McBrides in Bradford seems to virtually run on sodium laureth sulphate,
0:08:54 > 0:08:57'or SELS, as it's often called.'
0:08:57 > 0:09:01Sodium laureth sulphate is the primary detergent we produce here.
0:09:01 > 0:09:04It goes across shower gels, shampoos, baths.
0:09:04 > 0:09:07They all use sodium laureth sulphate, really.
0:09:07 > 0:09:11In terms of a week, we use about 100 tons.
0:09:11 > 0:09:12- 100 tons?- Yes.
0:09:12 > 0:09:15Michael Anderton, a product developer here,
0:09:15 > 0:09:18reckons I need the low-down of what goes into a typical shampoo
0:09:18 > 0:09:24if I'm going to understand the significance this single chemical plays in the formulation.
0:09:24 > 0:09:28So, here we've got the batches that Chris is halfway through making.
0:09:29 > 0:09:34There's a preservative to stop the shampoo going mouldy in the bottle.
0:09:34 > 0:09:39Fragrance and colouring for impressionable folks like me.
0:09:39 > 0:09:43There's a water softener and something to adjust the pH
0:09:43 > 0:09:45to a skin-friendly neutral state.
0:09:47 > 0:09:50But it turns out that up to 50% of shampoo is...
0:09:50 > 0:09:54yes, you've guessed it, sodium laureth sulphate.
0:09:54 > 0:09:55This is a ten-ton vessel.
0:09:55 > 0:09:59It'll produce between 10,000 and 20,000 bottles of shampoo.
0:09:59 > 0:10:03- 20,000 bottles - that would sort me out for a lifetime! - Absolutely.
0:10:03 > 0:10:07'So there it is - I've clearly been relying on sodium laureth sulphate
0:10:07 > 0:10:11'and its close chemical cousin sodium lauryl sulphate
0:10:11 > 0:10:12'to keep my hair clean.
0:10:12 > 0:10:15'But how does it actually work?
0:10:15 > 0:10:16'To answer that,
0:10:16 > 0:10:18'I'm going to need a scientist.
0:10:19 > 0:10:23'So, next stop Warwick University, where chemist Julie Ann Lock
0:10:23 > 0:10:27'wants to show me why this cleaning agent is so good.
0:10:27 > 0:10:31'She's making some sodium lauryl sulphate from scratch.
0:10:31 > 0:10:36'But instead of adding alkali like Mark and I did when we made soap, she's mixing fat with acid -
0:10:36 > 0:10:38'sulphuric acid, to be exact.
0:10:38 > 0:10:42'Amazingly, though, the result is mild enough to use on our skin.'
0:10:43 > 0:10:46If you leave this overnight to cool down,
0:10:46 > 0:10:48you do get something that looks exactly like this.
0:10:48 > 0:10:51This is our sodium lauryl sulphate.
0:10:51 > 0:10:55It feels exactly like a liquid hand wash or a shampoo
0:10:55 > 0:10:56or a conditioner.
0:10:56 > 0:10:59It has that feel of something runny and clean.
0:10:59 > 0:11:05'By changing soap's chemical recipe, you get a totally new kind of detergent.
0:11:05 > 0:11:07'And here's the killer reveal -
0:11:07 > 0:11:12'this synthetic detergent beats my home-made soap hands down in one crucial way.'
0:11:12 > 0:11:14Oh, yes,
0:11:14 > 0:11:19I can see there's a very distinct line of scum there.
0:11:19 > 0:11:20With hard water,
0:11:20 > 0:11:23which is present in lots of parts of the United Kingdom,
0:11:23 > 0:11:25you have calcium and magnesium ions.
0:11:25 > 0:11:28When they react with the molecules that are in your soap,
0:11:28 > 0:11:31they form little scums that don't dissolve in the water.
0:11:31 > 0:11:35'So when traditional soap mixes with hard water,
0:11:35 > 0:11:40'it creates a nasty scum that will lie on the skin or mark skins, baths and clothing.
0:11:40 > 0:11:43'But sodium lauryl sulphate, on the other hand...'
0:11:44 > 0:11:48You're not getting that scummy layer that we found before.
0:11:48 > 0:11:49It's much clearer.
0:11:49 > 0:11:55With lots of lovely bubbles. Just right for my shampoo.
0:11:59 > 0:12:01Because of their resistance to scumming,
0:12:01 > 0:12:03the SLES family of substances
0:12:03 > 0:12:06is much more versatile as a cleaner
0:12:06 > 0:12:08than our humble bar of soap.
0:12:08 > 0:12:11And they've got one more trick up their sleeve...
0:12:11 > 0:12:15just add salt solution and this stuff magically thickens up
0:12:15 > 0:12:21into a handy gel used in toothpaste, shaving foam and laundry liquids.
0:12:21 > 0:12:23Brilliant.
0:12:26 > 0:12:28Now, if the adverts are to be believed,
0:12:28 > 0:12:31then shampoo is only half of the hair care story.
0:12:31 > 0:12:34For that extra radiance and silky shine,
0:12:34 > 0:12:39we should all be taking another little bottle into the shower with us - conditioner.
0:12:40 > 0:12:44But is there actually any proof that conditioner works?
0:12:48 > 0:12:50'Back to the experts for some answers.
0:12:50 > 0:12:55'The gloriously titled analytical hairdresser Beverley
0:12:55 > 0:12:57'is going to put conditioner to the test for us.
0:12:59 > 0:13:03'Hair model Sharon has her locks washed all over with a basic shampoo,
0:13:03 > 0:13:07'like the one we saw mixed earlier. Then only one side is treated
0:13:07 > 0:13:11'with a precision, four-millilitre dose of an average conditioner.'
0:13:13 > 0:13:14Essentially, with a shampoo
0:13:14 > 0:13:18you're looking to cleanse the hair, take the dirt away from the hair.
0:13:18 > 0:13:21With a conditioner, you're trying to put something back on.
0:13:21 > 0:13:24'The objective is to treat the hair with something
0:13:24 > 0:13:29'that'll make it look and feel nicer, and make it easier and less painful to drag a comb through.
0:13:29 > 0:13:32'First up, how's the hair with no conditioner?'
0:13:32 > 0:13:35Here we go, Sharon. I'll have a quick go at combing your hair.
0:13:35 > 0:13:38Don't scream out like my six-year-old!
0:13:40 > 0:13:44Already, I'm hitting quite a bit of knotting here.
0:13:44 > 0:13:46Yeah, that's what I recognise,
0:13:46 > 0:13:49that big lump of tangle.
0:13:50 > 0:13:54'Michael explains the tangle has a rather shocking cause - electricity.'
0:13:54 > 0:13:57When you wash the hair, you leave a negative charge on there.
0:13:57 > 0:13:59You get a repulsion between each hair strand.
0:13:59 > 0:14:04Obviously, the more negative charge you've got there, the more repulsion you'll get.
0:14:04 > 0:14:09'Hair, or rather the keratin it's made of, naturally gains
0:14:09 > 0:14:12'the static electric charge which makes the hair fizzy
0:14:12 > 0:14:13'and reluctant to lie flat.
0:14:13 > 0:14:15'That makes it prone to tangles.'
0:14:17 > 0:14:19'So, what about the conditioned side?
0:14:19 > 0:14:21'Has that dealt with the electric frizz?'
0:14:22 > 0:14:26Straightaway I can notice a big difference.
0:14:26 > 0:14:28It's much, much smoother and silkier,
0:14:28 > 0:14:31all the words that I associate with good conditioner.
0:14:31 > 0:14:33Yes.
0:14:33 > 0:14:38'So it looks like the conditioner's having some kind of electrical effect on the hair,
0:14:38 > 0:14:40'making it much less tangled.'
0:14:40 > 0:14:43So this has been positively charged, in a way?
0:14:43 > 0:14:49Neutralised is what you'd say, because the positive charge is counteracting the negative charge.
0:14:49 > 0:14:51And the positive charge is coming from?
0:14:51 > 0:14:55- Something called the quaternary ammonium compound.- You what?
0:14:55 > 0:14:59- Commonly known as quats. - Oh, that's better. I can understand that.
0:15:00 > 0:15:03'So that's how conditioner works.
0:15:03 > 0:15:06'These anti-static quats are our wonderstuff
0:15:06 > 0:15:08'doing something pretty amazing -
0:15:08 > 0:15:11'giving out a positive electrical charge,
0:15:11 > 0:15:14'which counteracts the natural negative charge on hair.
0:15:14 > 0:15:19'Here at McBride they've even got a crazy combing contraption
0:15:19 > 0:15:23'that can tell them exactly how much difference the quats are making.
0:15:24 > 0:15:27'This Frankenstein-esque gizmo combs
0:15:27 > 0:15:31'samples of real hair - happily given by hair donors, I'm assured -
0:15:31 > 0:15:36'from root to tip and measures the force needed to do it.'
0:15:36 > 0:15:40This is the force of the comb moving through the hair here.
0:15:40 > 0:15:43Then along the bottom is the length of the tress.
0:15:43 > 0:15:47'The black line is for a tress of hair washed with the simple shampoo.
0:15:47 > 0:15:52'The red line is for a more expensive shampoo with a few extra proteins and vitamins thrown in.
0:15:52 > 0:15:54'Both are without quats.'
0:15:54 > 0:15:58Actually, there's very little resistance as it moves through.
0:15:58 > 0:16:01But towards the end of the tress, that's where the tangling starts to appear,
0:16:01 > 0:16:04so you get split ends. That's where you're getting to here.
0:16:04 > 0:16:07'So the hair washed with the more expensive shampoo
0:16:07 > 0:16:13'wasn't dramatically easier to comb compared with the basic shampoo.
0:16:13 > 0:16:15'But what happens when you treat the hair with quats,
0:16:15 > 0:16:18'shown by a green line?'
0:16:18 > 0:16:22- Wow, that's a marked difference, isn't it?- Absolutely.
0:16:22 > 0:16:24The much big bigger effect you get is from the conditioner.
0:16:24 > 0:16:28There's an 85% reduction in the force required to comb through the hair.
0:16:28 > 0:16:33- Visually, as peaks go it's like a molehill up against Mount Everest. - Absolutely, yes.
0:16:33 > 0:16:37'Clearly the quats are having a noticeable detangling effect.
0:16:37 > 0:16:41'They work on the individual hairs, allowing them to lie flatter,
0:16:41 > 0:16:44'making the whole head of hair look smoother.
0:16:44 > 0:16:47'Quats are clearly pretty clever stuff.
0:16:47 > 0:16:49'If I'm starting to sound a bit like an advert,
0:16:49 > 0:16:54'it's for once it seems I'm not being fobbed off by marketing claims.
0:16:54 > 0:16:58'There really is a science bit involved in conditioners.'
0:16:58 > 0:17:00So from now on,
0:17:00 > 0:17:04rather than fork out 20 quid on a fancy celebrity-endorsed shampoo,
0:17:04 > 0:17:08I might just opt for a more basic one
0:17:08 > 0:17:10then buy a separate conditioner,
0:17:10 > 0:17:13as long as it has a healthy dose of quats in it.
0:17:15 > 0:17:20'By the way, you probably won't see the word quats on labels
0:17:20 > 0:17:23'as it's a generic that encompasses many different chemicals.
0:17:23 > 0:17:27'But you might see cationic surfactant.
0:17:27 > 0:17:29'So that's my hair taken care of.
0:17:31 > 0:17:33'What about my precious teeth?
0:17:33 > 0:17:38'Time to look inside the tube that keeps my pearly whites white.'
0:17:39 > 0:17:41Hm. Not bad.
0:17:41 > 0:17:45When I'm buying a toothpaste, I tend to go for one that promises to make my teeth whiter.
0:17:45 > 0:17:48But now I want to decode the label.
0:17:48 > 0:17:50What's in there that's making it work?
0:17:50 > 0:17:52And is there a magic ingredient
0:17:52 > 0:17:57without which all of our smiles would be various shades of tea-stain brown?
0:18:02 > 0:18:04'According to my materials expert, Mark,
0:18:04 > 0:18:08'the best way to find out if a formula for toothpaste is user-friendly,
0:18:08 > 0:18:11'is to make some and test it on yourself.'
0:18:11 > 0:18:15'It looks like he's got another of his home brew experiments lined up,
0:18:15 > 0:18:19'but I've no idea why he's summoned me to the beach. Still, at least it's sunny.'
0:18:19 > 0:18:22Little bit of fresh air. Fresh, cold sea.
0:18:25 > 0:18:26Hi, Mark, how are you?
0:18:26 > 0:18:27Hi, Jane, how you doing?
0:18:27 > 0:18:32Nice to see you again. I see the shock of working with me last time has made your beard drop off.
0:18:32 > 0:18:36I'm on holiday on the beach. It's too hot for a beard.
0:18:36 > 0:18:37Why are we on the beach, then?
0:18:37 > 0:18:42It turns out the beach is the perfect place to talk about toothpaste and making toothpaste.
0:18:42 > 0:18:47The beach is the perfect place for ice cream and sun-bathing! Toothpaste, I'm not too sure.
0:18:47 > 0:18:50'Mark reckons teeth are unlike any other material
0:18:50 > 0:18:53'found in our bodies and need a special kind of cleaning stuff.'
0:18:53 > 0:18:56The enamel on your teeth is the hardest material in the body.
0:18:56 > 0:19:00It has to be, right? You've got to grind things up and it's got to last you a lifetime.
0:19:00 > 0:19:05Obviously, we use toothpastes to look after the enamel on our teeth.
0:19:05 > 0:19:09But other than knowing it's some kind of paste - err, it's in the title -
0:19:09 > 0:19:14and it's minty most of the time, I don't really know what else is in there.
0:19:14 > 0:19:15Let's have a look.
0:19:15 > 0:19:20To demonstrate what's so special about toothpaste, we're going to make some from scratch.
0:19:20 > 0:19:24You don't see this on Ready Steady Cook. We're going to make toothpaste.
0:19:24 > 0:19:26'First up, water.'
0:19:26 > 0:19:28Aqua.
0:19:28 > 0:19:30'Then stuff to make it taste nice...'
0:19:30 > 0:19:33Sodium saccharine. That's the sweetener.
0:19:33 > 0:19:34Peppermint flavour.
0:19:34 > 0:19:36'..and stop it going off.'
0:19:36 > 0:19:38Sodium benzoate. That's a preservative.
0:19:38 > 0:19:41'A cleaning and foaming agent we're already familiar with...'
0:19:41 > 0:19:45Sodium lauryl sulphate is now going in.
0:19:45 > 0:19:48I'm making a mixture here for something I put in my mouth,
0:19:48 > 0:19:50yet I've just tipped in
0:19:50 > 0:19:54a sort of sister of what goes into shampoo.
0:19:54 > 0:19:55This is weird!
0:19:55 > 0:19:57'..and a tooth strengthener.'
0:19:57 > 0:20:01- This is sodium fluoride. It hardens the enamel up.- Wow.
0:20:01 > 0:20:03- That's clever stuff, isn't it? - Yes.
0:20:03 > 0:20:05'There's a lot more in there than I thought,
0:20:05 > 0:20:09'but I'm not sure I've got to my toothpaste wonderstuff yet.
0:20:09 > 0:20:12'And I still don't know why we're on a beach.'
0:20:12 > 0:20:14- Ah, yes!- Carrageenan.
0:20:14 > 0:20:18- What's carrageenan? - So that comes from this. This is this seaweed.
0:20:18 > 0:20:23You basically make it into this powder, which is a gelling agent.
0:20:23 > 0:20:25I was expecting this to be a bit thicker at this stage.
0:20:25 > 0:20:27Come on, get it in there.
0:20:27 > 0:20:32I forget men can't multi-task. "Pouring and stirring - what are you asking me to do?"
0:20:32 > 0:20:35'Hm. But if there's a wonderstuff in toothpaste,
0:20:35 > 0:20:37'it has to be the one thing
0:20:37 > 0:20:40'that's particular to the job of cleaning teeth and here it is,
0:20:40 > 0:20:43'something called hydrated silica.'
0:20:43 > 0:20:48The key ingredient is an abrasive. That's what all toothpastes share throughout the history of time.
0:20:48 > 0:20:50- This is silica.- Silica.
0:20:50 > 0:20:53Yeah, hydrated silica. It's made from the sand we're standing on.
0:20:53 > 0:20:55- Really?- Yeah.
0:20:55 > 0:20:59'I'm not sure I like the sound of sanding my teeth down,
0:20:59 > 0:21:02'but this doesn't look like coarse grade.'
0:21:02 > 0:21:06You'll get a real feeling for it in your mouth. That's in toothpaste.
0:21:06 > 0:21:08It's very chalky.
0:21:08 > 0:21:12It's that chalky texture... It's a fine grit.
0:21:12 > 0:21:15You've got to get something that's hard but not too hard.
0:21:15 > 0:21:17- Right. - It's that gentle but hard thing.
0:21:17 > 0:21:21'Let's bung it in and see how it works with the rest of the ingredients.'
0:21:21 > 0:21:23So this is going to really thicken it up.
0:21:23 > 0:21:26- Come on, give it some welly. - I'm feeling it now.
0:21:26 > 0:21:30- It is turning into something. - Thank God for that!
0:21:30 > 0:21:33'As well as being an abrasive, the hydrated silica,
0:21:33 > 0:21:37'or posh sand, has given our home-made toothpaste its recognisable consistency.'
0:21:37 > 0:21:42I think that's about it, isn't it? Ta-da! We have made toothpaste.
0:21:42 > 0:21:43Can I taste it?
0:21:43 > 0:21:48Can I stop you for a minute because I think it'll be more exciting if we make stripy toothpaste.
0:21:48 > 0:21:52- We can make that here? - Well, we can try.
0:21:52 > 0:21:56'Apparently all we have to do is add some food colouring
0:21:56 > 0:21:59'to half the mixture, and if we keep the consistency the same,
0:21:59 > 0:22:01'by a miracle of physics,
0:22:01 > 0:22:05'it should come out of the tube in two stripes that don't mix together.'
0:22:05 > 0:22:07Oh, no, malfunction, malfunction.
0:22:07 > 0:22:10Houston, we have a problem.
0:22:10 > 0:22:12- Come on, drum roll. - Right, drum roll.
0:22:12 > 0:22:14HE DRUMS ON TABLE
0:22:14 > 0:22:15Oh, look at that!
0:22:15 > 0:22:18It is, it is, it is!
0:22:18 > 0:22:19Genius!
0:22:20 > 0:22:24'So, what's our home-made toothpaste like to use?'
0:22:27 > 0:22:28HE MUMBLES
0:22:30 > 0:22:35'OK, it tastes like a mouthful of chalk dust, but Mark wants me to appreciate how far we've come
0:22:35 > 0:22:37'in toothpaste technology.'
0:22:37 > 0:22:40Try this. This is Victorian toothpaste.
0:22:40 > 0:22:44- It looks like...sludge. - These are Victorian toothbrushes.
0:22:44 > 0:22:47- Oh, gosh, cinnamon. - Is that your favourite? No.
0:22:47 > 0:22:51I like cinnamon but not...
0:22:51 > 0:22:53I like it in a latte or a bun.
0:22:53 > 0:22:57I just want to make it clear - that isn't left over from the Victorians.
0:22:57 > 0:22:58We made that to a recipe.
0:22:58 > 0:23:01This is what the Victorians brushed their teeth with?
0:23:01 > 0:23:05Yeah, and the Victorians used this thing called diatomaceous earth.
0:23:05 > 0:23:08That's really the fossilised remains
0:23:08 > 0:23:11of little algae that lived millions of years ago
0:23:11 > 0:23:14and it falls down to the bottom of the ocean and makes this sediment.
0:23:14 > 0:23:17We've been digging it out of the ground ever since.
0:23:17 > 0:23:20'The Victorians spotted that this diatomaceous earth,
0:23:20 > 0:23:23'which also contains silica, by the way, was a useful abrasive.'
0:23:23 > 0:23:26It actually just looks like clay.
0:23:30 > 0:23:34Doesn't have much of a foaming action.
0:23:34 > 0:23:35Has no foaming action.
0:23:35 > 0:23:39'That's because the Victorians didn't have sodium lauryl sulphate.'
0:23:39 > 0:23:42It has gravel action, is what it has!
0:23:43 > 0:23:48'So, even though our modern toothpaste containing hydrated silica is easier on the tongue,
0:23:48 > 0:23:53'how does its effectiveness compare with the Victorian formulation?
0:23:53 > 0:23:56'I want to pit the two toothpastes against each other
0:23:56 > 0:23:59'to see if there's any difference in how they work.
0:24:00 > 0:24:03'And to do that, I'm going to need some special dental devices
0:24:03 > 0:24:07'just like they have at the Bristol Dental School.
0:24:07 > 0:24:11'Dr Emma MacDonald is going to measure the effectiveness of the diatomaceous earth
0:24:11 > 0:24:13'in the Victorian formulation
0:24:13 > 0:24:18'against the hydrated silica in our homemade modern toothpaste.
0:24:18 > 0:24:22'But first we need some teeth to test them on.'
0:24:22 > 0:24:24Oh, Emma...
0:24:24 > 0:24:25Yes, cow's teeth!
0:24:25 > 0:24:28- Look at the size of this. - Yes.
0:24:28 > 0:24:29Look at that.
0:24:29 > 0:24:34The beauty of using cow's teeth is that we can have a plentiful supply of them.
0:24:34 > 0:24:38Obviously, it's not the same as human enamel but it's very close.
0:24:38 > 0:24:43Is this the common size or have you found the Ken Dodd of the cow world here?
0:24:43 > 0:24:46No, they are actually that size.
0:24:48 > 0:24:53'A cow's pearly white is first cut to size using this delightful tooth saw.
0:24:53 > 0:24:55'Ouch!
0:24:55 > 0:24:59'Slices are then mounted in this rather unique contraption.'
0:24:59 > 0:25:01What's the little red bit there?
0:25:01 > 0:25:05That's actually covering an area of the enamel.
0:25:05 > 0:25:08- So it doesn't get brushed? - That bit doesn't get brushed.
0:25:08 > 0:25:11It's just the centre little piece that gets brushed.
0:25:13 > 0:25:18'The two different samples of paste are used to brush the teeth 5,000 times
0:25:18 > 0:25:22'before they're put into another fancy device, which gives us the results.'
0:25:25 > 0:25:28'First up, Emma's colleague, Sian, can reveal
0:25:28 > 0:25:31'how much the Victorian toothpaste ground down the tooth.'
0:25:32 > 0:25:35To me, that looks really dramatic.
0:25:35 > 0:25:38This is quite heavily magnified on this system.
0:25:38 > 0:25:42The amount of loss we got from this one was 0.6 of a micron,
0:25:42 > 0:25:45which is less than 1,000th of a millimetre.
0:25:47 > 0:25:51'Ah. So even though it felt like grit in my mouth,
0:25:51 > 0:25:53'I'm assured the Victorian formulation is effective
0:25:53 > 0:25:56'in toothpaste science terms.
0:25:57 > 0:26:00'Now, you might think that the much smoother, modern formulation
0:26:00 > 0:26:04'with hydrated silica would have less effect,
0:26:04 > 0:26:09'but, amazingly, the results are very similar.'
0:26:09 > 0:26:12What we're seeing is 0.81 of a micron.
0:26:12 > 0:26:17'So, modern hydrated silica gives you abrasive power,
0:26:17 > 0:26:19'but without the gritty texture.'
0:26:19 > 0:26:23'What's more, the size of the hydrated silica crystals can be manipulated
0:26:23 > 0:26:26'to make different kinds of toothpaste.'
0:26:26 > 0:26:30You can think of the particles within them a bit like clouds, really.
0:26:30 > 0:26:33For example, in a whitening toothpaste,
0:26:33 > 0:26:38you'll have the particles that will be quite dense, like a dense cloud.
0:26:38 > 0:26:40Then you could have light, fluffy clouds
0:26:40 > 0:26:42with less tightly-packed particles,
0:26:42 > 0:26:45which you might find in a children's toothpaste.
0:26:46 > 0:26:51'And hydrated silica earns its spurs as a wonderstuff in other ways too.
0:26:51 > 0:26:55'It's odourless, tasteless and chemically inert,
0:26:55 > 0:26:57'and turns up in the production of cosmetics,
0:26:57 > 0:27:01'paints and even beer. Clever stuff!'
0:27:03 > 0:27:05'When I first started this journey
0:27:05 > 0:27:08'delving into the science hiding in our bathroom cabinets,
0:27:08 > 0:27:11'I had no idea where it was going to take me.
0:27:11 > 0:27:14'But discovering the wonderstuffs at the heart of things
0:27:14 > 0:27:18'as mundane as shampoo and toothpaste has genuinely surprised me.'
0:27:18 > 0:27:21- Made from the sand we're standing on.- Really?
0:27:21 > 0:27:25I love the fact that the basic soap recipe hasn't really changed
0:27:25 > 0:27:30since they were using it to spruce themselves up for a night out in ancient Babylon
0:27:30 > 0:27:32about 2,000 years ago.
0:27:32 > 0:27:35But for me, the stand-out fact has to be
0:27:35 > 0:27:38that there's this amazing little chemical
0:27:38 > 0:27:42that can actually change the electrical charge on my hair
0:27:42 > 0:27:44and make it more manageable.
0:27:44 > 0:27:46That's brilliant!
0:27:47 > 0:27:50'Next time, I get back to nature,
0:27:50 > 0:27:54'on the hunt for some of the wonderstuffs that secretly keep our homes clean.
0:27:54 > 0:27:58'I get far too intimate with a serial dirt killer...'
0:27:58 > 0:28:00Oh, my God!
0:28:00 > 0:28:02'..that can disappear without a trace.'
0:28:02 > 0:28:04Oh, that's revived me.
0:28:04 > 0:28:09'I track down the natural source of a wonderstuff that's revolutionised wash day.'
0:28:09 > 0:28:11They knew what hard work was in those days.
0:28:11 > 0:28:15'And Mark whisks up a recipe for a home-made grease buster.'
0:28:15 > 0:28:18I knew when you called me here you were taking the piss.
0:28:26 > 0:28:28Subtitles by Red Bee Media Ltd
0:28:28 > 0:28:30E-mail subtitling@bbc.co.uk