- 1 week ago
Dr Karl's How Things Work - Season 2 Episode 5 -
Bread
Bread
Category
😹
FunTranscript
00:01Now over my long and varied career, I seem to have picked up quite a bit of knowledge.
00:07I certainly get asked a lot of questions.
00:10But don't let that fool you.
00:11I do not have all the answers.
00:14There are plenty of things that I have yet to investigate.
00:18These torrents, these rivers, these floods, these conveyor belts and chips.
00:23Like how everyday items are made.
00:26Ah, I missed.
00:27I'm going too far.
00:29And that's the idea of this series.
00:32What are these absolutely amazing arms.
00:34Aren't they incredible?
00:36Ah, it did it.
00:38Oh look, there it is.
00:39Yes.
00:40A perfect oval.
00:41I want to find out how things work.
00:45This time, we investigate a wondrous food item.
00:50Made in partnership with microscopic life forms, it's a marvel of food engineering.
00:57That's been with us, arguably, since the dawn of civilization.
01:03Fresh, hot and straight out of the oven.
01:06It's irresistible.
01:08Oh.
01:09Any way you slice it.
01:10I want to know.
01:12How do they make bread?
01:13How do they make bread?
01:15I'm at the Goodman Fielder factory on the Gold Coast in Queensland.
01:24Here they produce a staggering quantity of over 20 different types of bread.
01:29And I'm looking for the man who knows all about baking.
01:34Hi, g'day, I'm Carl.
01:35Hi Carl, I'm Peter.
01:36Now I believe you're one of the top bakers here.
01:38Yeah, I'm the quality manager.
01:39I'm part of the team here at the site, yeah.
01:41I've been baking for 42 years, Carl.
01:43Jeez man, you must know so much stuff.
01:46We produce up to 100,000 loaves a day.
01:49What?
01:50100,000 loaves a day.
01:52Divide that by 25, that's 4,000 loaves an hour.
01:56Yep, yep, 4,000 loaves an hour.
01:58That's one every second.
01:59Yep, absolutely.
02:00Wow.
02:01You will start baking at 12 today.
02:036 o'clock it'll be on a truck for tomorrow's market.
02:06Today, Peter is showing me the secrets behind their most popular loaf,
02:11sandwich bread.
02:13OK, the bread part we understand, but sandwich?
02:17People have been putting food between slices of bread
02:20for at least 2,000 years.
02:22But it didn't get the name sandwich until 1762.
02:26In the town of Sandwich, in England,
02:29there was a man, John Montague, who was also the Earl of Sandwich.
02:33Now, he loved his card game so much
02:36that in order to keep on playing
02:38and eat at the same time without getting his cards greasy,
02:42he had his valet bring him a slice of roast beef
02:45between two slices of toasted bread.
02:48People noticed, copied, the word spread,
02:51and that's how we have the word sandwich.
02:54OK, that's enough history for now.
02:56We're on the clock and there is baking to be done.
02:59This is going to be, I'm guessing, a white bread?
03:01A white bread, yep.
03:02OK, and I guess there's a recipe?
03:05Yep, we've got a recipe.
03:06We're going to get you to weigh up some of this.
03:07Oh, it's a recipe?
03:08Yes.
03:09OK, where do I start?
03:10You take the scoop, so there's salt over here.
03:12Salt? How much salt do I put in?
03:13If you look at the salt, you want 1.95 kilos.
03:15So, 1.95.
03:17Yep, that's a pretty big scoop.
03:19And this, nearly two kilos,
03:21is going to be part of the final weight of the big speed.
03:25300 kilos. Tip it all in.
03:271.9.
03:28Next, three scoops of what's called bread improvers,
03:33followed by what gives bread its soft, chewy texture, gluten.
03:38So that's all your dry ingredients?
03:40Yeah.
03:41They go into the wheelie bin, then to the back of the mixer.
03:44Man, those are huge for sure.
03:46Yeah.
03:47Now, storing ingredients in a wheelie bin might look unusual...
03:51Oh!
03:52..but it's a large container and on wheels.
03:56So now we're loading the dry ingredients into the mix.
04:01The last dry ingredient requires its own delivery system.
04:05So those pipes going in from the ceiling,
04:07that's your flour line going into the mixer.
04:09Flour?
04:10So the flour, there's a pipe like the guy over my head or something.
04:13Yeah, there's a 50-tonne silo out the back.
04:15It goes to a hopper,
04:17and it dumps the flour into the hopper up top.
04:20Next, the wet stuff.
04:22The water and yeast are pumped in
04:24with a touch of canola oil and vinegar.
04:27And now the mixing can begin.
04:30You can hear it vibrating now.
04:32Yeah, I've got my hand here.
04:34I can feel a vibration coming through the system,
04:36even though it's bolted to the floor.
04:38Now, this will mix for about three minutes.
04:40OK, and how many batches go through in a day?
04:42I'll do 200 batches a day.
04:43So what does 300 kilos of mixed dough look like?
04:48Oh, look at that!
04:52It was still spinning around while it was being thrown out.
04:54Yeah, correct.
04:58It's a bit sticky.
04:59Why is it so sticky?
05:00From the water and the oil and mixing it all together.
05:02And the extra gluten? Does gluten make it sticky?
05:04The gluten will hold it together.
05:06So what we do with this now is we actually...
05:09Oh, look at that!
05:10So this is how you tell where you've mixed it long enough.
05:12That's what they call the gluten strand.
05:14Like going...
05:15Yeah, holding it together.
05:16What, the criss-cross?
05:17Yeah, that gives you your structure of your bread.
05:19You can actually see the gluten with the naked eye.
05:21Correct.
05:22I had no idea.
05:23But how does this lump of floppy, sticky dough become a loaf?
05:29So what happens with this guy here?
05:31It'll go up into the spider.
05:37The divider, appropriately, of course, divides the dough.
05:40It rolls it into balls and then pumps them out.
05:44Oh, look at them go.
05:46At a mesmerising pace.
05:48So now you've got a dough ball.
05:50Theoretically, that would become...
05:52That'll become a loaf of bread.
05:54How much do they weigh?
05:55800 grand.
05:56Oh, look at this.
05:57There's a weighing scale.
05:58Got a check wire here that measures every dough piece.
06:01It takes less than a second to weigh each dough ball.
06:05And if they don't measure up...
06:07Whoa!
06:08Whoa!
06:09..but two of them fail.
06:12If it's below the weight we're looking for, it just rejects them.
06:16And so, is that just a blast of compressed air that pushes them off?
06:20That compressed air just pushes them off, yeah.
06:21Just air.
06:22I never thought that rejection would be so entertaining.
06:27Wow!
06:28Man, that comes at you so fast.
06:31I feel as though I'm going into a higher state of consciousness.
06:34Being hypnotised by the little balls of dough.
06:35All almost perfect except for the occasional real.
06:36Ah!
06:37Like that one!
06:38That one!
06:39And that one!
06:40That one!
06:41That one!
06:42Come on!
06:43Stop!
06:44Stop!
06:45Stop!
06:46Stop!
06:47OK, right.
06:48OK.
06:49The ones that failed rejoin the divider for a second chance of making weight.
06:56So, these are the good ones, so what happens to them now?
06:59So these go around, they're the right weight, so now they go around here.
07:02Oh my God, what's this?
07:03This is what they call the intermediate prover.
07:06What do they do in here, Peter?
07:07They're having a rest.
07:08They're having a rest?
07:09They're having a rest.
07:10Why?
07:11To let the yeast start to work.
07:13Yeah.
07:14And the dough starts to grow.
07:16Make the dough nice and soft.
07:18And this power nap takes only three minutes.
07:23Thanks to a high level of yeast in the dough.
07:26How much yeast would there be?
07:28There would be 8%.
07:298%?
07:3010% of that would be yeast.
07:32So, 1% would be 8 grams, so 64 grams of yeast.
07:36Yeast, yep.
07:37Wow.
07:38Mate, this dough is like a living creature.
07:41It is a living thing.
07:42Bread making, like many living things, has been evolving for generations.
07:49If you want to be poetic about it, you can think of bread as being a cornerstone of our
07:54civilisation.
07:55Way back, after we had learned to control fire, somebody came across some wheat and they
08:01got the grains and they ground them and did things and then baked them and blow me down,
08:06flat bread.
08:08And then, by accident, some wild yeast landed on the dough mix and fermentation happened
08:15and gases came off and suddenly you had a bread that rose.
08:19And that yeast powered rise can be seen and measured with a very simple test.
08:26Fermentation experiment 101.
08:28Yeast plus sugar plus water should give us some gas.
08:33Exhibit A, yeast.
08:35Now that is a living creature.
08:37If it wants to survive, seeing how it's not a plant, it needs some food.
08:41For this demo, instead of flour, I'll use sugar.
08:45When yeast eats sugar, it gives us carbon dioxide and a bit of alcohol which evaporates
08:50off anyway.
08:51Now, how are we going to tell this?
08:54We add the balloon, seeing if the balloon expands due to the gases, carbon dioxide, being
09:02produced.
09:03And, with a bit of patience, isn't it amazing what one short hour will do?
09:13All this bubble of carbon dioxide, oh my heavens, and that is why and how the dough will rise
09:19when you add yeast to the mixture to give you this beautiful fluffy bread.
09:24But the yeast will need a crucial helping hand from another ingredient.
09:29One that can help give this bread a perfect texture.
09:33Now, as you've guessed by now, I love stainless steel to pieces.
09:37And this huge tank has 15 tonnes of canola oil.
09:42It has two main purposes in baking.
09:45When you're baking the bread, the little tiny bubbles of carbon dioxide, they slide past
09:51each other because there's canola in between.
09:54And so you get a multitude of tiny bubbles instead of just one giant bubble.
09:58And secondly, the canola oil gives a soft, delicious mouthful to the bread.
10:06Producing this key ingredient for sandwich bread takes a surprising amount of effort.
10:12Luckily, Harold, the director of Cootamundra Oil Seeds in the Riverina region, is an expert
10:24in turning the seeds from the canola plant into cooking oil.
10:31So after it flowers, the seed pod is generated, and this is what contains the oil.
10:3740 to 45 percent oil in this seed.
10:40So the seed is going to be cold pressed in our plant.
10:44The plant is essentially an extraction process and a refining process.
10:50And step one is isolating the seeds.
10:54All right, so here we have our seed cleaning process.
10:58The seed has vibrated.
11:00It's a giant motorized sieve.
11:04Shake, shake, shake, and most of the other plant material is removed.
11:11So the cleaned seed, it travels across and up into the seed conditioner.
11:18Any more admixture that's still in there comes to the top just due to the difference in density.
11:24Now the black canola seeds are ready to be crushed in a machine ominously named the Expeller.
11:33Which turns and twists using pressure and friction to squeeze out the oil.
11:41Now as the oil is expelled, you can see there are still some solids that come with the oil.
11:46The oil then passes through a sieve for further refining and the meal is captured here and stored.
11:57The meal is then pressed a second time to extract more oil, with the waste meal going to animal feed.
12:03This oil is called the first press, but canola oil needs to be clear and neutral in taste and smell.
12:20So here we have a sample of the oil. Oil is still quite dark, has quite a bit of odour.
12:26To refine it, weirdly, you first need to dirty it up.
12:32You see, the oil is mixed with powdered natural clay, which can absorb any impurities and odours.
12:42This vessel here slowly agitates the oil-clay mixture.
12:47Once the clay is removed and the oil is filtered, you get this golden result.
12:53So on the right here we have the intermediate oil, which has been cold processed through the Expeller.
13:01And to the left is the final refined product that is more neutral in taste, in colour and in odour.
13:09And this is exactly what the sandwich bread recipe needs.
13:13Back at the factory, our does are out of the intermediate proofer.
13:23They've had their short rest and are slightly puffier than before.
13:28They'll still grow much, much larger, but first the balls will say goodbye to being balls.
13:34So your dough ball comes through the top, it goes through a series of four rollers,
13:41that flattens it out into a nice long sausage and cuts it into four pieces.
13:46It gets chopped here, and then what happens over there?
13:49It just turns the dough pieces around.
13:51Each of the four pieces gets flipped a hundred degrees.
13:53Yep.
13:54All this squishing, rolling, cutting and folding is not random.
13:59That's actually precise sandwich bread engineering, altering the internal structure of the dough.
14:05Makes the slice of bread stronger, and when you go to spread your margarine or your butter on there,
14:10stops it from tearing, so you've got a stronger cell structure.
14:13Peter says, I'll be able to test this out later down the line.
14:17But for now, this lumpy proto bread has some more rising to do.
14:23Are they actually going to rise all the way to the top?
14:25They're going to rise to the top.
14:26You're kidding.
14:27The yeast is now growing, it's moving.
14:30And inside the proving machine is a tropical, moist paradise for the yeast to multiply.
14:36The temperature set about 40 degrees.
14:39Yeah.
14:40And the humidity is about 80%.
14:41Wow, like the wet seeds in Darwin.
14:43Absolutely.
14:44And how long is the proving time like?
14:4575 minutes.
14:47Luckily, there's an earlier batch just coming out.
14:50And it's risen all the way to the top of the tin.
14:54Very soft and full of gas, full of air.
14:58Then it goes into the oven.
14:59So when the bread goes in, the lid comes down on the top of the loaf to make it square.
15:03When the bread goes in the oven, at 60 degrees it kills the yeast off.
15:11So you mean that my new best friend forever, the yeast, by the time they get to the end of the line they'll be dead?
15:18Absolutely.
15:19They're dying for us so that we can live.
15:20They're dying in the baking process.
15:22Thank you, Eugene, for your service.
15:24And here's the yeast's gift to humanity.
15:27You like that smell?
15:28I love that smell.
15:37Oh, that's warm isn't it?
15:38The bread temperature is about 96 degrees internally when it comes out of the oven.
15:42Now that's too hot to handle.
15:44So a machine called a D-panner uses precise jets of compressed air aimed at the sides of the tin
15:52and it unsticks the bread from the pan in one go.
15:55And then low pressure suction caps gently carry the loaf onto a conveyor belt.
16:03And now we've got a loaf of baked bread.
16:09It's warm.
16:10Oh, it's quite hot.
16:11And I can see the four sections which I've never noticed before.
16:14And then it goes down these conveyors into the cooler.
16:17Why do you have to cool it down?
16:19So you can slice it.
16:20Well, we can't slice it now, but we can do this.
16:24Oh my God, you're perfect in all the seeds.
16:26We broke it in the middle on one of the four-piece lines.
16:28You can see how nice and white and fluffy it is.
16:35Oh, it sort of vanishes in my mouth.
16:37It's too hot.
16:38It helps.
16:39Right.
16:40So it has to cool down.
16:41Yeah.
16:42For your slicing machine.
16:43Still, there's nothing like warm bread.
16:45I remember when I was a kid, my mother sent me down to the corner shop to buy some bread.
16:49It was so delicious that by the time I...
16:51You ate the middle out of it.
16:52I've eaten the middle out of it.
16:53Oh, I got into trouble.
16:55Oh, it's so bad.
16:57Anyway, to cool this bread, the facility uses a massive double spiral cooler tower.
17:03It blows cold air to bring the loaves to a slice-friendly 30 degrees Celsius.
17:12It goes up 10 metres or something.
17:14About 10 metres high.
17:15And what's the total length of all that?
17:17There's two and a half kilometres of belt in there.
17:19How long have you stayed in there for?
17:2175 minutes.
17:22And, yes, 75 minutes later, the cool loaves are ready for slicing and packaging.
17:30Under the watchful eye of my new guide, John.
17:35This is a bandsaw slicer.
17:37You might see bandsaws around for cutting metal.
17:40This is a very similar process.
17:42Inside, you can see the fingers.
17:44Those fingers move in and out so that you can adjust the slice thickness of the product.
17:50How thick can the slices be?
17:53From about one centimetre to about one inch thickness.
17:57I can just barely see it, but they are sliced.
18:00Is that me?
18:01I broke the light barrier.
18:02Yes.
18:03I was bad.
18:04Sorry.
18:05Yes, there is a light fence around the slicer.
18:08It'll safely stop it from slicing if any naughty fingers cross the beams.
18:13So, after the bread has gone through the slicer, it travels into the bagger system.
18:18As you can hear the air burst, that is inflating a bag and putting it over the loaves.
18:24When the machine misses a loaf, it takes a human about 12 seconds to get the bread into a bag,
18:31including putting on a clip to keep the bag closed and the bread fresh.
18:36But using robots and compressed air, the whole operation usually takes about a second,
18:41including adding the little clip thingy.
18:44The bread clip was invented in the 1950s, when Mr. Floyd G. Paxton, on a plane flight, carved one,
18:52using an old credit card and a penknife to reseal his free bag of peanuts.
18:58Today's version is exactly the same, but made of recycled cardboard.
19:03Now, how do we know if this bread is sandwich grade?
19:09Ah, g'day. Hi, I'm Carl.
19:11Hi. Hi, I'm Amy.
19:12Technical manager Amy at Quality Control has the answers.
19:16Yep, so this is what we do day to day.
19:18So we get the bread off the line, take the slice out.
19:22Ah.
19:23And put in this one.
19:26Right.
19:27And that will give you an image.
19:30Ah.
19:31OK, so I'm pretty sure that's not a multicoloured cushion.
19:34This machine reveals the hidden structural engineering of a slice.
19:38OK, and what are we looking at?
19:40Colour, dimension, shape, cell size and elongation.
19:45Cells are the tiny bubbles that make up the spongy structure of the bread.
19:50And these cells got formed because of the creation of carbon dioxide by the yeast?
19:54Yes.
19:55Right.
19:56With the sandwich bread, we want to understand if our crumb structure is open.
20:00And crumb just means the white parts.
20:03If there are too many big holes, that's a sign of a weaker bread.
20:09Testing the firmness of the bread.
20:11The firmness?
20:12Yeah, and how resilient it is.
20:13Resilience, like elasticity.
20:15Yeah, so when you touch it and it bounce back.
20:18Can I do that?
20:19Yes.
20:20We want a bit of Brazilian because when you've got a margarine on it, it just breaks.
20:27We don't want that to happen.
20:29So the bread has to have some structural integrity so it won't tear apart.
20:32Yes.
20:33And you say margarine rather than butter, why is that?
20:36Because I eat margarine.
20:38You don't eat butter?
20:39I do sometimes.
20:40Sometimes.
20:41And back at the slicing station, Amy has a practical way to show me what the scanner sees in the lab.
20:50Yeah, just wash this.
20:51Okay.
20:52And I'm going to do it this way.
20:53Oh, oh.
20:54And we will see at the end.
21:00Oh my God.
21:01So you've cut it long ways.
21:02Yeah.
21:03And that change alone turns a strong resilient slice into a fragile soft one.
21:10This one is tighter from structure.
21:12This is what we would look for.
21:14And that one, we've got some holes in more open.
21:17The cells are definitely bigger, aren't they?
21:18Yeah.
21:19When they come this way than this way.
21:20Yeah.
21:21I had no idea that the physicality of making bread was so important.
21:25It is, yes.
21:26But this massive operation got me thinking about bigger things.
21:30I'm very aware that the more loaves we produce, the more we potentially end up wasting.
21:37But there's something brewing in Melbourne, in Victoria.
21:53In the wee hours, away from public eyes, a group of men wipe clean a whole supermarket worth of bread.
22:02Once a month we go to supermarkets around the area and collect bread.
22:09All sanctioned, of course.
22:11So it's on the shelves, goes unsold after a few days and they have to rotate it out.
22:17And at the moment, you know, it's typically going to landfill or stock feed.
22:24And that's about 100,000 tonnes in Australia per year.
22:29That's roughly 314 million loaves each year.
22:34There's so much bread that's in surplus.
22:38But we can use it in our beers.
22:41And here in Clifton Hill, at Local Brewing Co.
22:45Let's try another delivery.
22:46Yep.
22:47Is where founders Paddy and Nick learned how to transform bread into beer.
22:54Ready for another batch?
22:55We can use any bread, but we're just focusing on white bread.
23:00It's the most wasted type of bread.
23:03We grind it up and we process it into a brewing ingredient that we then put into our beers.
23:10To do so, brewing wizard Andrew carefully combines selected enzymes with the breadcrumbs.
23:17These enzymes will break the starches down into sugars that the yeast can consume.
23:24Hello yeast, my old friend, we meet again.
23:28Except this time, it's brewer's yeast, which is great at turning sugars, in this case, this bread extract, into alcohol.
23:39Typically beer is made out of 100% malted barley.
23:48What we're looking at doing is replacing 20% of this with our extract, which is made out of reclaimed bread.
23:54And once the yeast joins the barley and liquid bread, it'll turn the mix into beer.
24:03And that would be around one loaf per case of beer.
24:07Then when it's ready, keg up the taps and we can serve it.
24:11Over the past year, more than 500 kilos of surplus bread were sneakily recycled into beer, all thanks to some clever science.
24:23We're finding it's actually easier to hide it in like a bigger, hoppier ale than it is to hide inside a simple, clean lager.
24:30But as we get better at it, we'll be able to use it in many different beers.
24:34And here, at the bread factory, they're also doing their part.
24:41So this is a return truck, which returns bread, which is not sold and stolen past its use-by date.
24:47And you don't want to just chuck it in the bin. So what do you do with it? I'm hoping something good?
24:52Recycle it into pig feed or cattle feed.
24:55Right. Well, at least it's getting reused.
24:58One thing is for certain, fresh bread is what everybody wants,
25:01but the window between fresh bread and stale bread is a short one.
25:07So John wants to show me how they move a never-ending stream of bread onto market shelves as quickly as possible.
25:18John, this is an Aladdin's cave of wonders.
25:22This gantry can hold roughly 85,000 units of bread.
25:26That's enormous. How does this whole gantry system work?
25:28So every crate that enters this gantry system or leaves it is assigned a unique identification code.
25:36It works out what stores ordered that product.
25:40How many different stores would you send it to?
25:43500-plus stores a day.
25:45The machinery and the team gather each load.
25:48And the stacks are ready for the road.
25:51We just push these straight onto the truck.
25:54You can straighten the truck there, yeah?
25:57Each truck is designed to be able to fit two dollies side by side.
26:02And then what about the space between there and the ceiling?
26:05This floor, once fully loaded, will be lifted right up so that we can fit another row of these ten high underneath.
26:12How clever!
26:13You're going out to people ranging from a little corner store up to the big megaplexes.
26:20Roughly what distance would you trucks delivering cover each week?
26:24Across Australia we would travel to the equivalent to the moon each week.
26:29Wow, that's like 380,000 kilometres.
26:32That is such a huge distance.
26:34It shows how important bread is that we have to cover that distance.
26:37Wow!
26:43On one hand, the story of bread starts with ancient agriculture, takes us through to the humble yeast, and finishes with a golden loaf.
26:53But bread is more than just a mixture of tradition and science.
26:58Bread is food.
26:59In each slice of bread, you have a mixture of agriculture, biology and community.
27:07It's a simple snapshot of our entire civilisation.
27:11Next time, we step into the making of a timeless trendsetter.
27:16The question is, how do they make...
27:19...boots?
27:29What do they make the same way?
27:30What do they make of it?
27:31This is your first time!
27:32How do they make it work?
27:33The Duncan H Hiçigar
27:35quinho is a pretty strong boy.
27:37Theまだiest thing is the
27:55Thankfullyal!
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