Proofing Pineapple Infused Vodka

[Sarafina Cartelli]

Hello everyone  

We're having slight problems over here with a new project.... How the hell do you figure out the proof of naturally infused spirits?

The pineapples have a ton of sugar and water in them, the sugar making the liquid denser therefore the hydrometer is completely inaccurate. 

Our antonpaar is also out of the question because of the damage the sugar would do to the equipment. 

We're at a loss over here and can't find anyone who has seemed to have similar problems. 

Please help, thank you!!!

-SC

[meerkat]

See parts 3 and 4 of the TTB Proofing Tutorial

[jeffw]

TTB has some lab distillation proofing procedure videos...https://www.ttb.gov/distilled-spirits/proofing-tutorial  Pretty straight forward.

[JNorris]

 

[Sarafina Cartelli]

Are there any methods that don't require a lab setup?

[jeffw]

Sure, send it to a lab and let them do it.  

[PeteB]

There is apparently a method that combines refractive index with density that can directly measure ABV containing sugars (obscuration)

As most would know the density increases with addition of sugar but decreases with addition of alcohol making hydrometers useless. But refractive index increases with the addition of both sugar and alcohol. Using both measurements and smart math the ABV can be calculated.

BUT as far as I am aware the method is not government approved.

The link below is for a device that apparently does the job.

Looks expensive unless you are doing thousands of samples.

http://scisol.com.au/product/alcotest/?fbclid=IwAR3MHrF2p0nMHVwilPnbQW10wgv-SGZZdP7sTWEQ3o_igLBqE6BGOAphZmk

[meerkat]

In the US the TTB distillation method is the only officially acceptable method of proofing.  But as PeteB has pointed out, if you have two separate measurements of two independent properties (i.e. density and RI in the case of the Rudolph machine) you can combine them with the applicable math and get to an accurate, but unofficial result.  You can do a similar procedure using much cheaper, but also much slower, equipment than the Rudolph AlcoTest.  With a simple drying oven and an accurate weighing scale you can measure the solids content after the infusion.  Once the sugar content is known it can be combined with the SG of the spirit to calculate the proof.  Here is an example done in AlcoDens LQ.

[Thatch]

We do our own proofing but if you're in a hurry and don't want to watch the TTB video and buy the lab still.  These people are who you want to talk to.

 

 

Lauren Sandell

Lab Manager

TTB Certified Beer Chemist

Kombucha Queen

 

https://kathinkalabs.com/

Cell: (970) 889-0208

 

Kathinka Labs

1402 Laporte Ave.

Fort Collins, CO 80521

[JNorris]

For anyone who wants to learn how to proof your own spirits using a lab still IM me, and I can teach you. 

You can spend $250- $500 on a lab still and learn how to do it yourself or pay a lab to do it for you every time.  Labs are charging....$90-$120 for a proofing test, ONE proofing test.  (Dang, I remember when this was $30!!! ...it looks like I am in the wrong business, maybe I should start a lab for testing/proofing spirits.)

Oh and you have to pay shipping.  AND you have to proof your spirits before you bottle, so a sample from every batch would need to be sent to a lab for proof testing before you could bottle.  You can see how the costs will add up quickly.

 

[Sorghumrunner]

On 11/25/2020 at 4:07 PM, JNorris said:

For anyone who wants to learn how to proof your own spirits using a lab still IM me, and I can teach you. 

You can spend $250- $500 on a lab still and learn how to do it yourself or pay a lab to do it for you every time.  Labs are charging....$90-$120 for a proofing test, ONE proofing test.  (Dang, I remember when this was $30!!! ...it looks like I am in the wrong business, maybe I should start a lab for testing/proofing spirits.)

Oh and you have to pay shipping.  AND you have to proof your spirits before you bottle, so a sample from every batch would need to be sent to a lab for proof testing before you could bottle.  You can see how the costs will add up quickly.

 

@JNorris With the distillation method for obscuration, is a water bath chiller a required piece of equipment to be able to measure volume 'the distillate is adjusted to the original temperature' and restored to the original volume by addition of distilled water.  We are pretty much always above 60F at our distillery, and of course, never precisely at 60F.   

[SCLabGuy]

Yes, you need a water bath to get your sample to a target temp before & after distillation. 

I tried using a cheap heat-only bath, set for a couple degrees above ambient. I had measurable ethanol losses due to evaporation. I replaced the bath with a more expensive lab bath w/ recirculation & heating+cooling. It's set to 60F which also aids in hydrometer proofing. No more evap losses. YMMV.

While the beginning and ending temperatures are not regulated, they do need to be the same before and after, which means you need an accurate thermometer to check your bath. My advice, don't skimp on your gauging tools too much. 

[Jedd Haas]

What brand and model of lab bath with chilling did you purchase?

 

[SCLabGuy]

Whatever I could scrounge up on Craigslist. I have a Beckman unit I like but quite a few brands make serviceable units. Thermo maybe? I look for a 5A+ compressor on the cooling side. 

I've also cobbled together something workable using a simple compressor-type chiller, pump & sous vide circulator wand in a plastic storage bin. You're heating and cooling and circulating all at once, which works surprisingly well, but isn't particularly energy efficient. Note that lab chillers will also heat and cool simultaneously to maintain temp.