Yeast nutrient use

I have been using yeast nutrient added at the end of my boils from the get go. Since I began making starters, I added nutrient to that as well. Any opinions if adding nutrient should be done in one or the other or both?

I generally add it to both, and haven't seen any negative results from doing so, just good healthy yeast and fermentation. When I put it in a starter, it's really only a pinch though. I think the Wyeast nutrient I use calls for 0.5 tsp in 5 gallons, so for making a 1-2 liter starter, you really only need a little bit.

I only use it for starters and high gravity beers. Starters because they're made with extract and then I'll add a little at the end of the boil for high gravity beers because of the extra stress level. I don't do it for normal gravity non starters because the grain creates enough nutrients for the yeast.

I use yeast nutrient in both the starter and the wort and I haven't had any negative results so far. Although I do tend to use dry yeast a lot and therefore I only end up putting the yeast nutrient in the wort since the dry yeast doesn't require a starter.

No harm in giving the yeast something extra to munch on in the starter and the brew... I used nutrient in my last starter, as well as in the wort... I use Wyeast beer nutrient most of the time, but this last batch I had a sacrificial packet of Cooper's yeast to include in the boil. The yeast was tossed into one of the bags when I was at the LHBS (zero charge)... So it was tossed into the boil so that it would be completely killed (put it in along with the first hop addition) and provide something more for the yeast to much on... Had good krausen within a few hours of pitching the yeast (yeast was pitched at 2am, krausen was by 9am)...

I might use some bakers yeast in future batches, not 100% sure. I think with higher OG brews it makes more sense than in lower OG brews. Although just using actual nutrient makes a lot of sense too.

You will get the best bang for your buck by adding it to the starter as you will provide the initial cells the nutrients they need to thrive. This way you will end up with a pitch of cells full of nutrients instead of a pitch of cells that have already spent much of their nutrients stores to reproduce from the starter.

To start thinking about why this would be important consider something like diacetyl production. One path for the formation of diacetyl is an offshoot of the production of valine. In this process active acetaldehyde combines with pyruvate to form acetolactate which is the precurser to the production of valine. Some of the acetolactate will escape the yeast cell wall where it undergoes oxidative decarboxylation (a reaction with oxygen that kicks off CO2), this new molecule is diacetyl. Since yeast are lazy like the rest of living things it would sooner use available valine instead of expending energy to produce its own. A yeast nutrient (ones that contain dead yeast) will be a rich source of valine. So, by providing that to a starter you will produce billions of cells filled with valine instead of billions of cells short on valine which means when they are making your beer they will be producing more diacetyl.

That said, I always add nutrients to starters and then a little more to the wort so all the new cells being created in it will also have a ready supply of nutrients so they can focus their energy on making good beer instead of producing amino acids and excessive amounts of byproducts in doing so.

Since I have been using Wyeast nutrient in my starters they have gone crazy. I also add it to the boil.