Staggered Addition of Sugar?

[D the Catastrophist]

I was looking at Jack Keller's Sweet Potato Wine recipe and I noticed that in the instructions you only added half the sugar(1 Lb) at the start, you then add the remaining pound of sugar 5-7 days later before pouring into secondary.

Can anyone explain why you would do this and what the benefit would be? For this recipe the potatoes were skinned and boiled in the water and then removed before the yeast was added so it doesn't seem likely it was due to concerns of off flavors.

 

[McMullan]

The idea is to reduce stress on the yeast. High sugar levels are said to put high osmotic stress on the yeast cells. I’m a bit skeptical, because yeast cells are tough as old boots. Staggered nutrient additions are a good plan, though, when ‘empty’ calories are offered to yeast.

 

[OakIslandBrewery]

I have always made sugar additions, small measured amounts over time rather than one big charge. I do agree with McMillan though, certain yeast strains are tough as nails.

It's the practice I first learned brewing big beers. Perhaps I'll break my habit next time and add it all at once.