German Brewing

Whats feeling here on using yeast nutrient added in the boil?

I load up nutrients in the starter. I only use them in the wort if the culture is on its last generation or two before being replaced.

I know Wyeast Nutrient contains zinc, which is supposed to be a no-no in LODO from what I understand. However if one is using Brewtan B, it acts as a metal chelator, so I'm wondering if you could get the benefits of the nutrient by supplementing with BB. The other nutrient brands consist of dead yeast cells, diammonium phosphate, urea, and other stuff.

Zinc, according to Kunze:

"The most important trace element in wort is Zinc, and at least 0.10-0.15 mg/l should be present."

He goes on:

"Zinc assists protein synthesis in yeast cells and controls their nucleic acid and carbohydrate metabolism. Zinc is also a necessary contact building block for alcoholic fermentation. Therefore, zinc deficiency can cause problems in fermentation."

He goes on to say Zinc content requirements are typically satisfied by the wort. He does state, however, that:

"If fermentation problems occur, the zinc content should be controlled."

He elaborated further in Chapter 3 about ways to control zinc content.

Brian.. I see you have nutrient listed in the ingredient bill in several of your recipes on the site. Are you still using it?
Thanks.