DIY yeast nutrient = poor flocculation?

[stageseven]

After reading Chris White's book on yeast and doing some reading on here, I decided to try out some DIY yeast nutrient. I wanted to keep it pretty basic, and have only used it on 3 batches now. What I got was some tablets of zinc and B-vitamin complex which I crushed up one tablet of each and divided (roughly) into 10ths. The ingredients were (per tablet)

50mg Zinc (as Zinc Gluconate)
and
10mg Thiamin (B1)
10mg Riboflavin (B2)
10mg Niacin
10mg B6
100mcg Folic Acid
10mcg B12
10mcg Biotin
10mg Pantothenic Acid
10mg PABA (Para-Aminobenzoic Acid)

I added one of these 1/10th a tablet mixtures to my boil in the various batches. What I've noticed is that while primary fermentation takes place seemingly smoothly, the yeast has not been flocculating or finishing as normal. It seems like it's taking a couple extra weeks for the beer to clear, and even then tastes more bitter and has some off aromas for an extended period before finally tasting normal. All these batches were fermented with WLP001 Cal Ale, which I've used before and had no problems with flocculation. It was also 3 different recipes, a pale ale, brown ale, and stout. Temperatures were in the low 60s during fermentation (at least 3 weeks each), then crash cooled/carbed for 2-3 weeks at fridge temperatures in a keg. Is there anything in these tablets that could be causing this to happen, or is my problem likely elsewhere?

 

[stageseven]

Ok, so between this question and the one over in this thread, I've been hung up on the question of zinc additions. I emailed Chris White mostly about the questions in the other thread, but he also answered my question about this blend of nutrient. I figured I would share that information with everyone here so that if it come up again in the future there will be an answer.

Basically what he said was that something in this nutrient must be binding with Calcium in the wort, so while I may be seeing some benefit in more complete attenuation, the lack of dissolved calcium is causing poor flocculation.

 

[samc]

Was the point to save money or just for experimental purposes?
Since vitamins are filled with binders and other fun stuff I'd expect issues with it. Even the higher quality vitamins still have a good percentage of filler/binder, etc.

I've found good success with Wyeast nutrient although I prefer using White Labs yeast when I'm not using Fermentis 05.

 

[badmajon]

Since vitamins are filled with binders and other fun stuff I'd expect issues with it

lol, sorry... fail. don't worry I do dumb stuff all the time

 

[stageseven]

Was the point to save money or just for experimental purposes?
Since vitamins are filled with binders and other fun stuff I'd expect issues with it. Even the higher quality vitamins still have a good percentage of filler/binder, etc.

I've found good success with Wyeast nutrient although I prefer using White Labs yeast when I'm not using Fermentis 05.

A little bit of both. With the cost of the bottles of vitamins being about $5 each, I figured I could do a good bit of experimenting for the cost of one pack of servomyces. I chose the vitamins based on a few threads on these forums where other people said that Zinc Gluconate was one of the only forms of zinc that naturally is able to be dissolved in wort, and that most of the rest of the nutrient content was b-vitamins. Others on here have had success using DIY nutrients, so next batch I'm going to try using just the zinc tablet to see if the problem ingredient is just in the b-vitamin complex. I just find the issue interesting and would rather play with it myself than go with store bought nutrients. That said, if it continues to be a problem I'll try the Wyeast nutrient.