Help me invent a rotating dry hopper

[thefost]

Ok here's another silly idea, basically stick the motor in the keg

Take a cup and attach it to the top of the dry hopper. Stick a battery powered case fan in there, remove the fins so its not circulating air. Case fan spins one way in floating cup, dry hopper spins the other way.

 

[max384]

Well the original idea was to add the hops, then purge the airspace with co2, then spin the liquid in a pressurized environment.

However, even if I didn't pressurize the keg and started spinning it some other way, I think the CO2 blanket would still be fine. I mean, we use stir plates all the time and that doesn't seem to oxidize the starter wort. Not sure how this is any different.

I'm with you though, I want to make sure there is 0% chance of oxidizing.

The entire point of using a stir plate IS to oxygenate the starter wort. That is literally the only reason we use stir plates when making starters. The yeast starters are done to maximize growth, not to create alcohol. Yeast grow and replicate much better in an oxygenated environment using aerobic respiration. If they are forced to, they will utilize anaerobic respiration (alcohol is a byproduct of this), but this is a much more energy inefficient process, and thus replication will not occur as rapidly as it would if they were able to use aerobic respiration.

This being said, if you have a CO2 blanket and it is airtight, than stirring won't introduce oxygen into the system. However, if your system is not airtight and oxygen is able to get in, than stirring can and probably will introduce oxygen into your beer.

Ok here's another silly idea, basically stick the motor in the keg

Take a cup and attach it to the top of the dry hopper. Stick a battery powered case fan in there, remove the fins so its not circulating air. Case fan spins one way in floating cup, dry hopper spins the other way.

I'd worry about sanitation issues with this idea. How are you going to adequately sanitize the motor and batteries? And to tell you the truth, I wouldn't be crazy about having that stuff in my beer vessel even if it were sanitized.

 

[KegWrangler]

Why not just put the keg on a lazy-susan. Then it would just take a small motor to keep the whole thing spinning since the only energy input needed is to overcome the friction of the ball bearings.

I'd try it with a remote control car motor - those have some pretty good torque.

 

[hungry4hops]

Lay the keg on its side and figure out a way to roll it like one of those hot dog rollers lol

 

[thefost]

The entire point of using a stir plate IS to oxygenate the starter wort. That is literally the only reason we use stir plates when making starters. The yeast starters are done to maximize growth, not to create alcohol. Yeast grow and replicate much better in an oxygenated environment using aerobic respiration. If they are forced to, they will utilize anaerobic respiration (alcohol is a byproduct of this), but this is a much more energy inefficient process, and thus replication will not occur as rapidly as it would if they were able to use aerobic respiration.

I always thought the stir plate mainly introduced oxygen at the beginning of the starter. Then when the starter wort starts fermenting a blanket of co2 is created and the starter wort no longer is getting oxygenated, and the stirring is mainly to keep the yeast in constant motion for better contact with the wort. Is this incorrect?

 

[max384]

I always thought the stir plate mainly introduced oxygen at the beginning of the starter. Then when the starter wort starts fermenting a blanket of co2 is created and the starter wort no longer is getting oxygenated, and the stirring is mainly to keep the yeast in constant motion for better contact with the wort. Is this incorrect?

Sorry, but this is indeed incorrect. Continual oxygenation is the purpose of a stir plate. The agitation produced by the stirring also disrupts the blanket of CO2 on top, thus allowing air flow (as opposed to stagnant water, where there is nothing to move the heavier blanket of CO2, and it does a much better job protecting the beer from oxygen). This is why aluminum foil is loosely wrapped around the top of a flask, rather than an airlock. You want air flow in and out of the flask when making a starter.

 

[grainbill]

maybe.. if you could retrofit another pressure relief valve and run the "drive shaft" through the retro fit?

 

[Bensiff]

When you grow a starter you are doing two things, intentionally introducing oxygen to grow biomass and doing so in a low gravity solution so as to avoid the Crabtree effect. At this point, like the growth stage of yeasts cycle when pitching into wort, oxidation is a non issue. Once the sugars are exhausted and the yeast have gone dormant is when oxidation becomes a particular problem. Now if you could run a sealed fermentation and install one of those little rotary fish food automated feeders on the inside of the fermenter and set it to do your dry hop additions without opening the container you would have little to no worry about oxidation. Of course you would still have to figure out how to stir it.

 

[biertourist]

Recirculation is the obvious solution for what you're trying to do.

If you're worried about dry hopping time, warmer temperatures also enable more oils to go into solution faster and pellet hops enable hop oils to go into solution faster than whole hops.

SOO if ultra rapid "dry hopping" is your goal, then you want a conical fermenter; dump all yeast / trub after primary fermentation is complete (yeast pull hop oils out of solution as the oils stick to the cell surface), then add your dry hops and recirculate through a pump pulling beer out of the very bottom of the cone and returning to the top of the fermenter or the top of the cone if the conical has a racking cane fitting at the top of the cone.

If you have a whirlpool kettle you could transfer from your fermenter back into your kettle for your "rapid dryhopping" and pump through the whirlpool; -this would make transfering off of the hop pellet crud and back into your fermenter also easy.

Just pumping liquid through a hop back, as has been said multiple times isn't a bad idea, but you want to fill the hop back from the bottom up slowly and then seal it to avoid oxygenation.

If you are doing this whole thing cold, it will take a bit longer, but it's more akin to Sierra Nevada's Hop Torpedo system.

The rotating dry hopper is not the right solution for what you're trying to do; if you just want to do it because you just want to make a rotating dry hopper in a pressurized vessel, that's a totally different issue; just proceed with the unnecessary crazy in that case.

-For what it's worth, recirculation during fermentation also makes fermentation proceed faster, so a gentle pump that can recirculate through a conical could pull double-duty, if you're interested in turning over lots of hoppy beer rapidly.

Adam

 

[TrickyDick]

Lay the keg on its side and figure out a way to roll it like one of those hot dog rollers lol

Roller dog IPA!!


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[dyqik]

Just pump beer out of the liquid tube and back in through the gas tube. That'll circulate the beer over the hops (in the keg). Flush the system with CO2 before you start (and maybe lay the keg on its side so that there's no problems with the pump having to draw liquid up the height of the keg).

You can clean the system with beer line cleaner and starsan in exactly the way you already do for your beer lines.

ETA: Or you could use a second keg and a randall and pressure transfer from one keg to another.

 

[ArkotRamathorn]

Could do a combination of ideas. Make the internal basket (that holds the hops) and the bar that attached to the lid stationary. Then spin the keg itself. Removes the added problems of sealing a spinning drive shaft, now you just have a stationary shaft attached to a keg lid.

Or you could throw the hops and beer into the keg, purge and cover with CO2. Then strap the keg down into the bed of a truck then go 4 wheeling through a mud pit for a couple hours. Have some fun while you're turbo dry hopping:rockin:.

 

[Stealthcruiser]

Crazy as all this sounds............I like the hot dog roller idea the best.

You already have the dip tube in there, which could be the basis, or foundation for your "agitator", if you will.

Devise some type of detachable "paddle", that was easily sanitize-able, that could be clipped on the dip tube.

You could sacrifice 1 corney keg lid,to be used amongst all your kegs.

Attach your hop basket to the lid..........Solid stainless rivets come to mind, ( 'cause I do sheet metal work!).

Prep and install them properly, and they will hold pressure, as they do it all day long , ( rivets), on an aircraft fuselage.

Build a rack with inline skate wheels top and bottom, that will cradle the corney, with a stop at each end so the keg won't "crawl" out of the cradle.
The "stops" could include a skateboard wheel.......(hmmmmm, 'cept for the "notches" on the handle end of the keg....)......WAIT!

Make the handle end higher on the rack, then only one "stop" idler would be needed.

Rig up a slow, friction drive setup, where the drive wheel bears on the keg body...........Windshield wiper motor comes to mind.

Load the keg, purge, lay it on the cradle, and turn it on.