First Run On A Reflux-VM

by **Matt S** » Wed Apr 10, 2013 11:56 am

Hey there everyone, had my first run of a VM Reflux (MACSTILL BUILT), and I have to say, its a great piece of machinery.
I have it attached to the Pure Distilling 2000w boiler.
I ran through it 9L of low wines (35%) and let it equilibrate for a bit over an hour. Temp settled on 77.9C for most of the run (until the end), and the run took me about 5 hours.
One thing is, I couldn't get it past 90% ABV, even though it wasn't running fast (a few constant drops a second, with the gate fully open collecting hearts).

How would I better run this still?

I let it re-equilibriate after I first collected the fore shots, and then another 10 minutes re-equilibriating it after I had collected what i thought was the end of the heads, and then let it run wide open through the hearts till I got to the tails, and let it re-equalibriate again to condense whatever ethanol was left to the hearts.

Cheers

by **MacStill** » Wed Apr 10, 2013 12:04 pm

Try 40% ABV and a full boiler charge, the more alcohol available to process the better it will run.

You might also need to repack the column after the shipping, you'll want the top of the packing around 50mm below the outlet.

and a bit of practice ;-)

by **Matt S** » Wed Apr 10, 2013 12:21 pm

Nice :handgestures-thumbupleft:
Is it also worth putting the extra packing into the main, long column?

by **Matt S** » Thu Apr 11, 2013 2:39 pm

I put the other last bit of spare packing in, will report back on how it runs now.

by **Matt S** » Tue May 07, 2013 11:11 am

I have done another round. Took your advice Mac, and filled the 30L boiler with 20L of 40% low wines.
I ran it super slow, after first allowing it to equilibrate for almost two hours.
For some reason I still only pulled of 92% ABV. Would a few drops of water in the measuring cylinder change the ABV when I am testing it? The cylinder and the Alcometer were not completely dry.
Why do you guys think I am not able to pull 95%+?

by **BackyardBrewer** » Tue May 07, 2013 11:28 am

Matt S wrote:I have done another round. Took your advice Mac, and filled the 30L boiler with 20L of 40% low wines.
I ran it super slow, after first allowing it to equilibrate for almost two hours.
For some reason I still only pulled of 92% ABV. Would a few drops of water in the measuring cylinder change the ABV when I am testing it? The cylinder and the Alcometer were not completely dry.
Why do you guys think I am not able to pull 95%+?

You should be aiming for ~95%. 95% is really only achievable with everything perfect - column temp, wash temp, water flow...all those things will knock a percent or two off.

I don't know anyone getting MORE than 95% with home still gear.

Other reasons:
Your alcometer is off by a point or two? Check it in water which should be zero.
Your temp on the ethanol needs to be 20º which is how most alcometers are calibrated to - are you also using a thermometer to make sure it's not too warm or too cool? No? Neither are most of us ;-)

I am also surprised you're letting it sit for two hours! That's way too long for me, that would make the still day twice as long. Anyone else have thoughts on the power and water use to let it reflux for 2 hours? 20 minutes is the most I'd do in a bubbler and 10 minutes is the most I'd do in a reflux still.

Mac knows this rig better than anyone, so take my thoughts with a grain of salt.

by **Matt S** » Tue May 07, 2013 11:44 am

I ran it according to Kiwi's VM reflux tutorial which says to let it equilibrate for at least an hour.
I did read check the temperature, and adjusted it for the temp change. The alcometer says 96%, but I adjusted it because the temp was 70C.

by **MacStill** » Tue May 07, 2013 12:02 pm

Matt S wrote:The alcometer says 96%, but I adjusted it because the temp was 70C.

What temp was 70c ?

by **Matt S** » Tue May 07, 2013 12:08 pm

Shit, I meant the spirit was 70F, not 70C.
Sorry for the confusion.

by **The Stig** » Tue May 07, 2013 2:23 pm

70DEG F = 21.1111DEG C

by **MacStill** » Tue May 07, 2013 2:28 pm

The Stig wrote:70DEG F = 21.1111DEG C

8-}

by **Sam.** » Tue May 07, 2013 3:01 pm

Reckon you were getting as high as your gonna get then bud at that reading might as well call that azeotrope

by **BackyardBrewer** » Tue May 07, 2013 4:05 pm

sam_and_liv wrote:Reckon you were getting as high as your gonna get then bud at that reading might as well call that azeotrope

As Sam said, you are so close you shouldn't worry. This is a very organic hobby when you do it in the backyard...Unless you have lab conditions or consistent and exact reproducible distillery conditions it will be different every run by a small amount.'

Sometimes you'll have the exact same ABV but less volume in your yield...Slight difference with the yeast pitch or the wash temp - you name it. Any slight variation changes results but I like that (as long as the results aren't bad and I'd say yours are excellent!)

by **Matt S** » Tue May 07, 2013 10:52 pm

Glad to hear that I am still doing well.

Reason I am asking though, as to why I have not hit the 95% mark is I hear of a lot of people getting there with even a shorter column.
Could someone let me know if they think letting it equilibriate a tad longer is good for the run and the ABV?
One of the main reasons I want to hit that higher ABV is there is still a tad too much wash taste coming through, which isnt terrible, but I would prefer to perfect it if possible.

by **BackyardBrewer** » Tue May 07, 2013 10:57 pm

Matt S wrote:Could someone let me know if they think letting it equilibriate a tad longer is good for the run and the ABV?

Brother try less! Perhaps the longer you're keeping it in the column and in the wash then the more wash flavour is getting picked up.

I still say a two hours is way too long. Get up to temp, wait 20mins & get stillin'. Let's see if that makes a difference - it will to your power & water bills;)

by **MacStill** » Tue May 07, 2013 10:59 pm

If you hit 96% @ 70DEG F = 21.1111DEG C after temp correction your as close to 95 as you want to be..... 8-}

by **Sam.** » Tue May 07, 2013 11:16 pm

MacStill wrote:If you hit 96% @ 70DEG F = 21.1111DEG C after temp correction your as close to 95 as you want to be..... 8-}

I thought I said that in my other post :think:

Mate if you have spirit coming off at 21c and you are reading 95% you are doing about as good as your going to get, then make good cuts and you can't do a great deal better than that :handgestures-thumbupleft:

by **Matt S** » Tue May 07, 2013 11:34 pm

Cool, cool.
Yeah the ABV when I checked it was 96%, and after I did my temp corrections the ABV was 92% pretty much the whole way through the run.
Which still isnt bad, I guess I just set up false expectations of things HAVING to be a certain way.

by **Matt S** » Tue May 14, 2013 8:17 pm

Hmm, onto drinking my third run now. I am not happy with my product. It's okay, but I have a lot to improve on.

by **BackyardBrewer** » Tue May 14, 2013 8:22 pm

Matt S wrote:Hmm, onto drinking my third run now. I am not happy with my product. It's okay, but I have a lot to improve on.

Why? What's wrong with it? Cuts? Flavour? Smell?