Dry Hopping with Magnets?

[BrewBarron]

So I've been doing a little research before I brew my first IPA. I read up on dry hopping and it seems there are many techniques out there. My first thought was that I wanted to dry hop in the keg, but learned that its possible that the hops can stay in too long and effect the flavor. I read that some people tie their hops to a string and seal the keg and later fish them out when their flavor is right. That sounds ok, but I want to avoid decompressing the keg, opening it up, fishing the hops out and then resealing and re-gassing. So I was thinking....

What if you bag your whole hops up with a stirbar or something else that will be attracted to a magnet but also halfway sanitary. Then, drop them in a keg, and attract the bag from the outside of the keg with a magnet. Place the magnet approx. halfway down the keg and wait. Then, after you are pleased with the taste, move the magnet up the keg to the empty airspace (assuming you tasted the beer plenty of times to create an empty airspace). Thus, removing the hops from the beer without opening the keg. Then, if you start to lose flavor, aroma, etc, move the magnet back down into the beer.

I have yet to try this, but did confirm I could control something with a magnet from outside the keg. The question now would be what do I use inside the keg, can it hold on to a bag of hops and actually bring it out of the beer into the headspace.

Any thoughts? Has anyone else tried this?

 

[shortyjacobs]

Sounds like a good idea. I'm guessing stirbar on the inside, neodymium (rare earth, hard drive magnet) on the outside? Only problem is the stirbar will lose, uh, "magnetivity" if it spends too long in the field of the other magnet...

 

[Catt22]

Only problem is the stirbar will lose, uh, "magnetivity" if it spends too long in the field of the other magnet...

The stir bar will not lose strength due to exposure to the other magnet. Quite the contrary IIRC.

 

[PurpleJeepXJ]

Ya that is the most simple way to magnetize something metal... put it with another magnet. What about adding a large solid plastic fishing bobber to the hop bag so that if the magnet falls it will be supported by the bobber and not to the bottom of the keg? Other than that I think you are a genius!!

 

[azscoob]

I use a large herb ball to dry hop in the keg, I sanitize a plastic zip tie and zip the sanitized herb ball to the top of the dip tube.

Once it is hopped to the desired level, I enjoy a few pints, this lowers the level and the herb ball is no longer submerged in the beer, it doesnt get over hopped and it can just sit in the keg til I clean it out.

 

[shortyjacobs]

The stir bar will not lose strength due to exposure to the other magnet. Quite the contrary IIRC.

I should have clarified...normal magnets stored opposite pole to opposite pole are fine...I was talking about hard drive magnets, which have screwy magnetic fields because they are curved, and can cause problems...

 

[PurpleJeepXJ]

You are correct... I would stay away from hard drive magnets for the sole reason that they are probably made in china and you have no idea what they put in their metals over there or if they are sanitized.

 

[Walker]

i suspect you will have a bit of an issue getting enough magnetic force to hold a soaking wet bag of hops to the side of the keg, above the beer.

What is your reasoning for not wanting to just open the lid and pull the hop bag out the old fashioned way?

 

[Walker]

how about this?

one strong magnet (since it'll have to have enough force to hold up the weight of the hops, the weight of the beer absorbed in hose hops, and the weight of whatever other magnetic thing is inside the hop bag).

On the inside, get a piece of iron and put it in a plastic zip-loc bag, sealed it, sanitize the outside, and put it inside the hop sack.

or use a second magnet on the inside, but still do the zip-loc thing to keep it sanitary and not in direct contact with the beer.

edit: if you have a foodsaver or other vacuum sealer, you can "permanently" encase the inside thing in a couple layers of plastic for this use and then just sanitize the outside and put it in the hop bag when you want to do this.

 

[tjpfeister]

I like this, it's a clever idea. I agree with walker on using a rare earth magnet inside and out.

 

[BrewBarron]

i suspect you will have a bit of an issue getting enough magnetic force to hold a soaking wet bag of hops to the side of the keg, above the beer.

What is your reasoning for not wanting to just open the lid and pull the hop bag out the old fashioned way?

Lazyness mostly. That and foam. Well, lazyness, foam, and saving gas.

I mostly keg, but do bottle from the keg on occassion, and when I do, after I drop the pressure, fill the bottles and repressurize, I have had problems with excessive foaming. I am sure there are some other issues than me just dropping and raising the pressure, but thats been my experience.

For the most part, I'm just trying to think of a more efficient way to dry hop and also maintain the most control over the process. So, with this, I thought if I can avoid opening the keg and control my dry-hopping by simply using a magnet, why not. It may or may not work, but hopefully its worth a conversation and some experimentation.

 

[wildwest450]

Unless you drink very slow it takes WAY longer to get all the supposed off flavors in the keg. I regularly go 6 weeks @42F with no gassiness or off flavors. The generalization that most on here seem to accept as truth is way off base when it comes to dry hopping.


_

 

[BrewBarron]

Unless you drink very slow it takes WAY longer to get all the supposed off flavors in the keg. I regularly go 6 weeks @42F with no gassiness or off flavors. The generalization that most on here seem to accept as truth is way off base when it comes to dry hopping.


_

But do you hit a point in your beer when you have imparted enough hops flavor/aroma and want to remove the hops and let it stabilize, or, have you dialed in an amount of hops that you know is good, and just let it ride through the life of the keg?

I have zero experience with dry hopping, so this is pretty new to me.

 

[carrotmalt]

I've used a mire mesh ball and flavorless dental floss before. I wonder if you could just pull the dental floss with the lid still on to raise it above the liquid level? Seems easier than magnets, but I haven't actually tried it. I just took the lid off and pulled them out before. Might be worth a try.

 

[wildwest450]

But do you hit a point in your beer when you have imparted enough hops flavor/aroma and want to remove the hops and let it stabilize, or, have you dialed in an amount of hops that you know is good, and just let it ride through the life of the keg?

I have zero experience with dry hopping, so this is pretty new to me.

They only give off so much aroma. I use the teaball dental floss method, I just usually never pull them out. If your happy with the aroma, yank them out.

 

[BrewBarron]

I've used a mire mesh ball and flavorless dental floss before. I wonder if you could just pull the dental floss with the lid still on to raise it above the liquid level? Seems easier than magnets, but I haven't actually tried it. I just took the lid off and pulled them out before. Might be worth a try.

I thought about that, but wasn't sure if you could pull on the string with such a tight seal on the lid. I agree, that would be easier, but wouldn't allow you to re-introduce the hops if your flavor/aromas were starting to fade. I don't know if this is even a problem given the shelf life of a keg of beer.

Or, again, I could just stop being lazy and just open the darn keg and throw in more hops or take them out. But, whats the fun in that.

 

[Walker]

They only give off so much aroma. I use the teaball dental floss method, I just usually never pull them out. If your happy with the aroma, yank them out.

Agreed.

Part of the OP mentioned concern about keeping the hoppiness "right" by needing to pull them up and then perhaps put them back in again later.

Putting them back in probably won't be necessary. If your keg is sitting around THAT long, then you simply need to drink more.

 

[SCBrew]

Are corny kegs not slightly magnetic themselves?

 

[Walker]

Are corny kegs not slightly magnetic themselves?

high grade stainless steel (like the kegs are made of) is not magnetic.

 

[bja]

Are corny kegs not slightly magnetic themselves?

Certain grades of stainless steel are slightly magnetic. The problem is, those grades will develop rust. I've never seen any signs of rust on a corny.

 

[nutty_gnome]

You want cow magnets available from ebay and any cattle rancher store. They are used to combat hardware disease. They look like oversized silver caplets and are a little thicker and longer than your middle finger. I played around with them to weight dry hop bags because they are long and thin enough to get through a carboy neck. Mine have a non-reactive outer coating and I haven't had any trouble with that, it may even be stainless (I forget at the moment). When you get two together they are pretty powerful. I HAVE NOT tried to drag a bag up a keg with them, but I bet this is what you are looking for. PLenty of heft to weight the hop bag and plenty magnetic. Link to ones like I have used in the past:
http://cgi.ebay.com/lot-2-Alnico-5-...577?pt=LH_DefaultDomain_0&hash=item518e66dbc1
or
http://cgi.ebay.com/Magnet-Source-0...332?pt=LH_DefaultDomain_0&hash=item3f06aa2fec

I bought mine for like 3 bucks a piece off of ebay last summer. I used them for a while and then decided that I like to 'free hop' all my hops and now I dont use a bag at all. I originally found the idea for them here on HBT.

 

[Hang Glider]

Sorry....

I am SO confused....





there is such a thing as "too much" hops?

 

[samc]

Op - great idea, but I agree with the premise that leaving your hops in the keg until it kicks will rarely (never?) give you those vegetal off flavors that people wax on about. I've left hops in kegs for months, flavor/aroma fades without leaving grassy notes. However throw in a bunch of green grassy hops in your keg and that's what you will get coming out from day one until it fades if you are lucky. Garbage in Garbage out!

 

[ScubaSteve]

F'ing magnets....how do they work?

 

[FireDancer]

Forgive me ... I just can't help myself ...
Too much hops? Is this not like too much happiness?

 

[shortyjacobs]

F'ing magnets....how do they work?

Electrons have an intrinsic angular momentum called spin. If you want, you can visualize them as tiny balls rotating on an axis, though that's not actually how it is. Because electrons have charge, their intrinsic angular momentum creates a magnetic field.

In most matter, the electron spins are oriented every-which-way, so the magnetic fields all cancel out. But in ferromagnetic materials, the spins are aligned, so there's a net magnetic field around the object.

It's exactly the same mechanism that creates electromagnetic — electric charge in motion — but it happens due to intrinsic angular momentum rather than the linear momentum of an electric current in a conductor.

There are really three types of intrinsic magnetism. There's ferromagnetism, ferrimagnetism and paramagnetism. In ferromagnetic materials, the spin orientations of the electrons align spontaneously, no doubt due to magnetic interactions between the atoms that make up the material.

Ferrimagnetic materials are similar, but they differ in macroscopic structure. Instead of having all the magnetic moments aligned, there are little "cells" each with its own net magnetic moment, and the overall magnetic field of the material is the sum of the magnetic fields of all these little cells.

Paramagnetic materials are not normally magnetic, but in the presence of a magnetic field, all the magnetic moments can align to create a semi-permanent magnetic field. You know the trick where you scrape a sewing needle across a permanent ferromagnet in order to magnetize it, then float it in water to make an improvised compass? That's paramagnetism. If the needle is subsequently subjected to a physical shock, the magnetic moments will become unaligned and it will no longer be magnetized.

As to why ferromagnetic, ferrimagnetic and paramagnetic materials can have the properties they have, it's got to do with chemistry. Many elements have their electrons arranged in such a way that their magnetic moments all cancel out. But in certain materials, magnetic moments tend to become parallel, rather than antiparallel as usual, which means they sum up instead of canceling out. Because only certain materials have the atomic (and molecular) structure to support this kind of additive magnetism, only certain materials can be intrinsically magnetic.

<----Source.

 

[BrewBarron]

Man, we're getting schooled here. I like it.

As to the too much hops deal.......I like a hoppy beer as much as the next guy, but being a noob to dry hopping, I found out that people keep some strict regiments when it comes to the time frame they keep their hops in the beer. Some keep it 1 week, 10 days, 2 weeks, etc. I wasn't sure if this is just the minimum time it takes to impart the hoppyness they want before its time to keg/bottle, or a maximum time before they start to get worried about the flavor. Anyway, I may just experiment with my next batch and split it up into two kegs. I'll toss and leave hops in one keg, and then try this whole magnet thing to remove the hops once I reach a good flavor profile in the other keg. We'll see if it works.

 

[Atl300zx]

ive done keg hops for over a month, i always dry hop for 2 weeks, never had any vegetal taste.

I bought into the whole dont leave dry hops in there for too long thing for a while, but after leaving some in secondaries and kegs for extended periods of time, i no longer worry.

 

[MAC80]

I know this is a older post, but I was hoping that someone has tried this or has some information that may help. A little back ground first, I am new to brewing and gathering equipment/researching the processes. I have purchased a Fermentasaurus with a pressure kit and I looking to make a NEIPA and then do a closed transfer to a keg. Seems the fermentasaurus has issues using the bottle to dry hop. Looking for a solution to dry hoping without taking the pressure off of the fermentasaurus. Have seen different thoughts about adding hops during pitch so I wanted to use magnets to hold the hops in the top and then lower them after fermentation has slowed. I don't really need to pull them back out but it might be nice to keep them on the side so that it doesn't get in the way of the pick up tube for the closed system. I like the idea of using a vacuum sealer for the inside magnet. Has anyone tried this or have any other ideas?

Thanks

 

[Queequeg]

When I keg hop, I don't get grassy flavours from over extraction. If anything the grassy flavours come early and die off

 

[rconway91]

F'ing magnets....how do they work?

F'ing rainbows after it rains