How to Get the Eis out of the Eisbock

[AlexKay]

Anyone else out there freeze-concentrating their homebrew? I just did this for the first time, and it was a mess. I froze it in a Fermonster with a spigot, figuring I could just drain the liquid out and leave the ice behind. Heh. The slush quickly clogged the port, and I ended up messily extracting the liquid with an auto-siphon.

Anybody have any tips or tricks to get this done more easily? I’m wondering if a screen in front of the output port would help. Or maybe a mesh bag to lift out the ice, a la BIAB? (FIAB?)

 

[AlexKay]

A little internet searching and I’m now confused as to the legality of freeze concentration. If there’s a limit as to how much water can be removed before it is considered too much like distilling, I of course did my best to honor that limit. If it is illegal regardless, please take this question as a hypothetical in preparation for some time in the future when I’m in a different jurisdiction.

 

[GilSwillBasementBrews]

I do not believe freeze concentration is illegal of course laws in your area might differ.

as for removing the ice I would think using a bucket would be easier just remove the lid and pull out the block of ice. Just a thought though. The only time I tried it was with a cider in a gallon jug just froze it then upended it till the liquid ran out and discarded the rest.

 

[AlexKay]

My experience (very limited -- I've now done this for two batches) is that the "frozen" part is mixed in like a Slushie, thick enough to block the port on the spigot, but by no means removable as a block. So I'm thinking about a bag or sieve of some sort. For a bag I worry about sanitation. I could pour through a colander, I suppose, but then I worry about aeration -- though that's probably not worse than the auto-siphon, and it would be easier. Or is there a trick to getting the ice to form a block?

 

[cactusgarrett]

I've had an eisbock on my to-do list for years, and I'm finally getting around to one this week. The brewing part, that is, not the freezing/transferring. However, like I do, I've researched the hell out of this ahead of time, and I've settled on the intention of doing this in a keg. Anything else that's not a closed-system I worry about oxidation.
http://www.lugwrenchbrewing.com/2012/06/freeze-condensing-eisbock-photos-and.html
However, I don't see anything keeping it from experiencing the same thing you are: a homogenous slush as opposed to delineated phases of liquid & solid. I would imagine that under pressure, though, a bit of slush will transfer through the jumper and clogs won't be as prevalent.

Also, don't sweat the legality. This is something that's been argued about for decades. Even if it were illegal (which I don't believe it is on our level), similar to the 100/200 gal per household rule, no authorities are monitoring and lining up at your door to breech and clear your caches.

 

[AlexKay]

Let me know how the keg works. It’s awfully nice to have the clear plastic to see how freezing is going, but I could do without if it got me a better way to transfer.

I haven’t been sweating a little oxidation — I figure it’d be within the eisbock style.

 

[corkybstewart]

I've done it in a keg, not on purpose, but this winter if it ever happens I want to do another. I just pressured up on the keg and put it in a bucket of warm water so the dip tube would freeze. Then I pumped it into a clean keg.

 

[cactusgarrett]

Let me know how the keg works. It’s awfully nice to have the clear plastic to see how freezing is going, but I could do without if it got me a better way to transfer.

I haven’t been sweating a little oxidation — I figure it’d be within the eisbock style.

The general target is 20-25% loss (by weight) of water, so I plan on freezing/removing/weighing/repeating until I hit that mark.

I haven’t been sweating a little oxidation — I figure it’d be within the eisbock style.

My attempt is going to be a traditional bavarian eisbock, so the base beer is a maibock - less amenable to oxidation.

 

[AlexKay]

The general target is 20-25% loss (by weight) of water, so I plan on freezing/removing/weighing/repeating until I hit that mark.

So … freeze, pressure transfer concentrate to second (purged) keg, then freeze -that- keg, pressure transfer back, and so on … Seems like it would work. Again, update here or somewhere else once you’ve done it!

 

[cmac62]

I've only done it with cider, but I used 2 ltr bottles, froze them and upended them into mason jars and let them drip until the ice was fairly clear. If I do it again I think I would make a lightly hopped D bock and do the same method with maybe some antioxidant like kmeta or ascobic acid dosed into the mason jars. Then dry hop with a hop ticture or something similar.

 

[cactusgarrett]

then freeze -that- keg, pressure transfer back, and so on

That's my plan. This being my first time with freeze concentrating, I don't expect to hit the temps & timing on my first shot. Therefore, I plan to err on the side of too slow, as opposed to freezing too much too quickly, with the idea that i can just keep transferring until my target weight is hit. To do that, I'll stabilize the whole thing down 25F before going slower after that. My research says a 15% ABV solution freezes around 19F, and if I'm starting around 1.090, I'll give it a wider berth.

I've heard of people just throwing the keg in the freezer on full blast (0F?), then about10hrs later doing the transfer, but I've also heard that too rapid of freezing can trap beer, sugar, alcohol, etc. in the ice because it forms so fast. I don't know how much validity there is in that, and I have the time, so I plan on taking it slow.

 

[Dr_Jeff]

I had a keg freeze one time as the thermostat was going out in a kegerator.

The beer was foamy & I wondered WTF was going on as it had been pouring fine, but the beer had a kick to it.
The when the keg kicked "empty" and I pulled it out to replace it, it was still heavy and I knew what had happened.
I set the "kicked keg" in the garage and in a bit when I came back, it had a nice layer of frost from the bottom to about a quarter way up.

I let it thaw, then tapped it to see what was left, just a watery semi beer tasting something.
I set it with the dirty kegs and dumped what was left on keg cleaning day.

 

[corkybstewart]

I had a keg freeze one time as the thermostat was going out in a kegerator.

The beer was foamy & I wondered WTF was going on as it had been pouring fine, but the beer had a kick to it.
The when the keg kicked "empty" and I pulled it out to replace it, it was still heavy and I knew what had happened.
I set the "kicked keg" in the garage and in a bit when I came back, it had a nice layer of frost from the bottom to about a quarter way up.

I let it thaw, then tapped it to see what was left, just a watery semi beer tasting something.
I set it with the dirty kegs and dumped what was left on keg cleaning day.

That's how I accidently created eisbiers. My beer didn't get foamy but it did kick my butt pretty hard and then the kegs started running out. I didn't bother to taste the remains, I just thawed it and poured it out.

 

[madscientist451]

I've done it with cider in a bucket in the chest freezer. Set it as low as it will go and freeze the bucket. Pull it out and let it start to thaw, but keep an eye on it, then open the bucket and pull out a bug chunk of ice and place in another bucket. I was concentrating unfermented apple juice and the ice portion still had a sugar level, so I saved it and made beer with it. Not sure if this would work with beer, but its worth trying; this method is likely the way it was traditionally done, but they used outside winter temperatures, not a freezer.

 

[Beermeister32]

Keg idea has issues too. I left my temperature probe dangling outside of my lagering refrigerator once by mistake. I’m not even sure you could charge it adequately with CO2 to push liquid. This keg was a frozen block.

 

[cactusgarrett]

Keg idea has issues too.

The idea is that you don't freeze the keg solid - only for (at the coldest, freezer temps) 10 hours. The transfer is made shortly after a slush has formed.

 

[Beermeister32]

If I recall last time I saw something like this, they dumped it in a bucket and removed the ice layer that formed on the top. Not sure the beer in the bucket ever turned to slush. Not sure of the oxidation implications.

Maybe if you did it from a bottling bucket and poked a hole through the ice, you could pour off the tap. Dunno….

If you tried it from a keg, could be hard to get past the ice block at the top if one formed. If the outlet dip tube froze up you’d be SOL…Really would be hit or miss in a keg. Timing would be critical. Anything is possible I suppose.

 

[Dr_Jeff]

Keg idea has issues too. I left my temperature probe dangling outside of my lagering refrigerator once by mistake. I’m not even sure you could charge it adequately with CO2 to push liquid. This keg was a frozen block.

View attachment 752368

You are real lucky that the keg didn't split or mess up the lid.

I bought a large lot of Coke kegs and they had been stored outside, many still had syrup in them, temperatures had gotten down to the single digits.
There were at least a dozen or more that had either split or deformed the top or both.

 

[Beermeister32]

Definitely.

 

[cmac62]

I think if you freeze it slowly, at say 30* f for 12-24 hours the water will freeze with the ETOH dropping to the bottom of the keg and you could just use the tap to collect the concentrated beer. If done correctly I guess you could even do a closed transfer into a purged keg to reduce O2 exposure. Also, if it does happen to freeze solid you could let it thaw out for an hour or so and then transfer what has melted and again the ETOH would melt first and drop to the bottom. Sounds like a fun experiment.

 

[corkybstewart]

If I recall last time I saw something like this, they dumped it in a bucket and removed the ice layer that formed on the top. Not sure the beer in the bucket ever turned to slush. Not sure of the oxidation implications.

Maybe if you did it from a bottling bucket and poked a hole through the ice, you could pour off the tap. Dunno….

If you tried it from a keg, could be hard to get past the ice block at the top if one formed. If the outlet dip tube froze up you’d be SOL…Really would be hit or miss in a keg. Timing would be critical. Anything is possible I suppose.

The liquid in the bottom of the keg has a high alcohol content and freezes at a much lower temp. I warmed mine up a little bit in case there were loose ice chunks but it never quit flowing

 

[JohnDBrewer]

I've done eisbocks a couple times. Used doppelbocks as the base. Put about 2gal in each keg, froze them for a day or two, took out for about 1 hour and transfer what would come out to a fresh keg. The key is starting with a good base beer otherwise the concentrate only makes a weak beer worse. Focus on making a solid base beer.