What to look for when choosing a bulk neutral grain or flavored base spirit supplier?

[mendodistilling]

I'm interested in working with some bulk spirits to expand my trials with my still and i was wondering what to look for when inquiring with the big guys. Ive got some suppliers from the adi source guide and I'm going to call them soon and ask them sources of ingredients, etc. But im wondering if they offer lab tests on unwanted higher alcohols, etc. Also, would they be open to disclose ingredient sources, etc. How has your relationship gone with these guys?

[Brothers Vilgalys Spirits]

I'd like to second this request, we're closing in on our DSP (just fixing bond stuff) and would like to nail down a good supplier for this. In my case, I'll be blending a liqueur w/ GNS so not actually distilling anything (not until we got the $$$ anyway).

When buying GNS in bulk, do most of you filter / redistill it? Does it tend to be pretty harsh in terms of congeners and flavor? Any quality-based recommendations?

For product samples, I've been using Everclear to blend this stuff and that works pretty well for what it is.

[John McKee]

Most of the GNS suppliers are sourcing from large fuel Ethanol refineries, which means that the large reputable GNS suppliers are providing about as clean and clear a product as one can possibly get. In fact, if you request it, you can get GNS which is purified past the distillation azetrope.

The ASTM standards (test suite) for what goes in your gas tank include tests for PPB (parts per billion) contaminants (among others), which means for the most part GNS material is cleaner than what most any of us smaller distillers tend to produce.

So...

1. You can get a QA/QC (certified) analysis of the GNS in question.
   
2. You can also get the source material used to produce the GNS.
   
3. Finally, anyone who is redistilling or filtering GNS from a major producer are just making it less pure. If you're going the GNS route, just use it.
   

Best,

John