1.Prepositional phraseFrom the beginning; starting with no advantage or prior preparation.
"There were so many errors in the program that the programmer decided to rewrite it from scratch.; When the writer finished writing his book, it was stolen and now he has to rewrite it from scratch.; He had no money and no rich friends, so he had to build his business from scratch."
2.Prepositional phraseFrom basic materials or raw ingredients.
"She said she wanted to build a new house from scratch.; He was out of pancake mix so he had to make the batter from scratch."