Rotovap

grim

Did this for a gelato guy once too, he was trying to make a bourbon gelato, and he was reducing and dealcoholizing bourbon on the stove. I didn't love the stovetop product, the de-alc/de-water version was much better. Kept the heads fraction separate for this one, and I believe he used an eye-dropper to add it back in when they were freezing it back down (whatever that's called, not an ice cream guy).

jbierling

@grim said: Did a few bottles of bourbon for "dry January" for friends. Not necessarily zero alc, as you need to distill off a 'heads' fraction first, and add that back in after removing the bulk of the ethanol.

The time I tried this, the de-alc remainder was very cloudy. How did you turn that into something that looked remotely clear like bourbon? Were the heads enough to clear it up a little? Adding water to bring back to volume didn't help.

@grim said: You absolutely can not do this at atmospheric, the higher temperature will absolutely destroy numerous flavor compounds, you need to do this under deep vacuum at very low temperatures, and have a chiller that can support the temp ranges you need (we run around -10c or -20c depending on the time of year).

That's probably an argument for keeping bottles out of the sunlight too.

grim

We tried adding back water to reduce the concentration as well, but that killed stability and shelf life. I don't know that I really cared much about the appearance.

Found it just easier to adjust cocktail recipes and use the dilution from the ice instead. An old fashioned for example, really helped mask.

I don't think this is at all a path to a non-alcoholic whiskey. Could be part of the puzzle, but I doubt this is going to be economical enough to make sense.

Kind of related? We've played around a bit with quillaja as an emulsifier, it's used in high oil content clear beverages. The stuff has been out for a while, but seems to have exploded as an ingredient with the cannabis beverages - as they need to hold higher amounts of oils and terpenes. Hoped we could make a wicked concentrated gin, but it's not solubility in ethanol is a problem at anything more than minuscule quantities. It also foams to high heaven when shaken - which may be a plus or minus depending. This may be an answer to non-alc gin though, it absolutely works as a clear emulsifier in water-based. I would almost guarantee some non-alc gins are using this. I'll need to rotovap another bottle to see if it works to improve stability/quality of the non-alc bourbon, never thought of that. Again, this is basically screwing around, and screwing around for friends.

I don't think filtering is the option either, usually I'm pretty outspoken that filtration's impact on flavor tends to be smaller than many expect, but given the solubility issues here, filtration is going to suck out flavor.

grim

These guys did all the legwork to get approvals/gras/etc:

Q-NATURALE® high-efficiency emulsifier @ Ingredion

This wasn't the product we'd played around with. Looking at the page they talk about alcohol solubility, so curious if they've refined or extracted a more specific set of saponins from Quillaja that are more soluble.

grim

Much of the motivation here was being able to use vermouth or some other oddball mixers we can't produce ourselves, in our tasting room, which isn't permitted here.

Some may look at de-alc'ing Antica as heresy, but it 100% works.

jbierling

@grim said: I don't think filtering is the option either, usually I'm pretty outspoken that filtration's impact on flavor tends to be smaller than many expect, but given the solubility issues here, filtration is going to suck out flavor.

I did have the thought that the TCW Graver GFC Haze Pre-Filters might help since I've had good luck before with them for things that I really wanted to sell at 80 proof (instead of mid 90s).

@grim said: Much of the motivation here was being able to use vermouth or some other oddball mixers we can't produce ourselves, in our tasting room, which isn't permitted here.

Does NJ have some particular restrictions? We're a winery and distillery, I haven't lost any sleep mixing the two for a cocktail (vermouth).

jbierling

Looking at the rotovaps on eBay it is striking that almost all of them don't include glass -- which is the main reason I hate glass. Its not if it is going to break, its when.

Obviously glass is useful in a still for a lot of reasons, but it makes me wonder why more components aren't made out of vacuum rated stainless. Also, the typical small size of the openings into the evaporator and condenser glass is a PITA.

grim

Yeah, these things are not production devices, even the larger R-220 with the thicker glass is fragile.

Always wondered if you could reverse engineer the thin-film evaporators you see in industrial settings. Similar approach as a rotovap, but they don't rely on trying to spin glass.

DonalF

Not a rotovap question but a vacuum still question. Does anyone know if the dragonstill pots (specifically the 380 L pot) can work under negative pressures (i.e. under vacuum) and if so, how low can the vacuum go before there's a risk of impolsion? Any idea what thickness of the 304 stainless steel in the wall of the vessel is?

jbierling

@DonalF said: Not a rotovap question but a vacuum still question. Does anyone know if the dragonstill pots (specifically the 380 L pot) can work under negative pressures (i.e. under vacuum) and if so, how low can the vacuum go before there's a risk of impolsion? Any idea what thickness of the 304 stainless steel in the wall of the vessel is?

I'm sure @Smaug will answer, but the answer is likely to never run them under any sort of vacuum.

Smaug

The kettles are rated for 15 psi.

EDIT: 15 psi positive pressure. I have no idea if there is a negative pressure rating. Our factory does not test for negative pressure.

grim

The minute you pull vacuum on a vessel in a commercial setting, you enter the same territory as running a high pressure vessel (in the US anyway, though would imagine similar in Europe). This means your vacuum vessels are going to need to carry a certification (ASME in the US), a nameplate with design limits, and usually annual testing that your local government, and probably insurance company, will want. Generally if a tank is going to be under partial vacuum, it's prudent to design it to operate under Full Vacuum (usually indicated as FV on the nameplate), to avoid catastrophic damage if full vacuum is accidentally pulled, which is usually pretty easy.

Just because a tank can support # psi pressure, does not mean it can support the same differential as vacuum. There is no rule that works to convert a pressure rating to a vacuum rating.

Good example is a soda can, which is designed to hold anywhere from 90-120 psi pressure, but pull even a small vacuum and it fails catastrophically.

Might a tank that isn't rated work once or twice? Sure, maybe. 50 times? Maybe, maybe not.

Cue obligatory vacuum catastrophe video:

https://www.youtube.com/watch?v=Zz95_VvTxZM

grim

The vacuum rating would also need to apply to the collection vessel, and any associated piping.

Though the piping is probably the least worrisome part of this.

Column diameters do need to be upsized for vacuum use, as the vapor speeds are far higher, and flooding becomes a major issue.

Realistically, you'd probably need a 12" or 18" column on a 380l tank to keep vapor speed in check. Or settle with pot-still only.

DonalF

Thanks for your help folks. Much appreciated.