To begin from the very beginning without the aid or advantage of something that is already prepared or completed. A noun or pronoun can be used between 'start' and 'from.' The folder with my outline and notes got deleted, so now I have to start the whole project again from scratch.We don't have time to start from scratch, so let's just use some cake mix from a box.

Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.

to start from the very beginning; to start from nothing. Whenever I bake a cake, I start from scratch. I never use a cake mix in a box. I built every bit of my own house. I started from scratch and did everything with my own hands.

McGraw-Hill Dictionary of American Idioms and Phrasal Verbs. © 2002 by The McGraw-Hill Companies, Inc.

To begin from nothing at all, without having a head start or some other advantage. This term comes from racing, where a horse or runner is said to start from scratch when starting from the usual point—that is, the line “scratched” (marked) on the course—while others may be starting ahead with a handicap. The term was transferred to other bare beginnings by the twentieth century. George Orwell used it in Coming Up for Air (1939): “We’d no fishing tackle of any kind. . . . We had to start from scratch.”

The Dictionary of Clichés by Christine Ammer Copyright © 2013 by Christine Ammer

Start at the beginning with no advantage. The scratch line was a stripe across the ground where a race began. Starting from scratch meant having no advantage against others in the race where handicaps allowed some entrants shorter distances to run.

Endangered Phrases by Steven D. Price Copyright © 2011 by Steven D. Price

Aight, the fuck are you lookin at self?
You wanna piece of me?
Ohh man, shit
The story of my life
If I could start from scratch, I wouldn't change shit
Same red bandana, same four-fifth
Same G-wagon, same hoodrat bitch
Workers in the kitchen cookin up my shit
Same telephone booth, same connect
That mean the same hollow tips breakin up in my chest
Same bloody t-shirt, same address
Same 'Dogg Food' album bangin in my tape deck
Homey if I can make '94 today
I'd tell Eazy and Dre to bring back N.W.A
I woulda told 'Pac not to stomp out Orlando
Told Puffy and Big about the Rampart scandal
I got too many dead homies, fuck a rap career
I'd give anything in the world to bring back my nigga Tear
Seem like we was just in Magic City yesterday
If I could bring back my homeboy Charles, he would say
If I could start my life from scratch
If I could take away the pain of the past
If I had another chance, I would do just that
I'd give anything just to go right back
If I could start my life from scratch
If I could take away the pain of the past
If I had another chance, I would do just that
I'd give anything just to go right back
Homey if I could rewind the hands of time
I woulda cut off the PS2 at 12:49
Nigga I'm a gangster, I stay on my grind
Who knew 11 minutes later I'd get shot with my own 9
I was two beeps away from a flatline
When you a Bad Boy niggas don't wanna see you Shyne
Dre said it's my turn, he call it Game time
23 inch Lexani's, bitches call 'em LeBrons
I'd give my own life if I could change God's mind
Bring Baby Loony back at the drop of a dime
He let off a whole 'K, got shot one time
That was a cool nigga, I wish he had nine lives
My brother Jevon died cause he chased the cat
It's a dog eat dog world, Jesus please holla back
I got a confession to make, it's called payback
If you don't wanna listen, show me where Pastor Ma$e at
If I could start my life from scratch
If I could take away the pain of the past
If I had another chance, I would do just that
I'd give anything just to go right back
If I could start my life from scratch
If I could take away the pain of the past
If I had another chance, I would do just that
I'd give anything just to go right back
I woulda told Big Will they raid every Tuesday and Thursday
When pigeons in your coupe, you gotta watch where your birds lay
Woulda told V to stay sober
When niggas 'Beg for Mercy,' that mean the beef is over
Told Meeks take the Porsche back, drive the Rover
Told Slim hit reverse on that hardtop Nova
I woulda changed a couple of lines when I wrote 'Soldier'
So I wouldn't have to live lookin over my shoulder
My life is like a Impala, ridin three-wheel motion
I been front to back, side to side
Level my six-four frame out, keep on rollin
Keep your family far away and your enemies closer
Picture this, The Source suckin Benzino's dick
Tryin to be the big fish in the pond, you know how them piranhas get
You dead when that green line go flat
If you could start your life from scratch, you couldn't change that
If I could start my life from scratch
If I could take away the pain of the past
If I had another chance, I would do just that
I'd give anything just to go right back
If I could start my life from scratch
If I could take away the pain of the past
If I had another chance, I would do just that
I'd give anything just to go right back