I have a batch fermenting in an all in one stainless steel pot. something like a the northern brewery’s mega pot.
I read somewhere that using magnets for a stainless steel fermenter to drop your nylon bag for dry hopping is not recommended.
Any idea why is that?
Thanks.
I am not sure why you would want to use a magnet in the hop bag. 304 stainless steel is not magnetic so it you are trying to get the magnet to stick to the bottom of the mega pot to hold the bag down in the beer, it ain’t gonna happen. Secondly, magnets are usually made from rare earth materials and I am not sure I would want to take the chance of anything from the magnet leeching into the beer.
I assume you are using pellets for dry hopping? If you want to weight the bag down, see if you can find a stainless steel weight to do so. The stainless steel balls that are used in spears of Sankey kegs work well but finding them might be a pain, unless you know someone who has cut the top off of a keg (obtained legally) to make a keggle. You may be able to find something else that is made from 304 stainless that will do the job. Just be aware that some stainless steel will rust, so you want to make sure that you use 304. As an afterthought, you might contact SABCO in Toledo, Ohio and see if they will sell you some of the stainless steel balls they use in Sankey keg spears.
Hi,
Thanks for your reply.
I wasn’t planning on using magnets to weight it down but to keep them stuck on top unti it was time to but the hops in. Then when it was time to add the hops, pull the magnet from outside so the bag falls into the beer.
looks like you’d like to minimize oxidation and not have to open your fermenter, but the magnet idea will still probably result in magnets coming into contact with your beer, which could be bad. can you find magnets that are coated in a food grade plastic that you could use?
The magnet is on the outside of the keg. Something steel in the bag on the inside, right?
You’ll need magnets much stronger than garden-variety refrigerator magnets, and they have to stick across a distance of ~1mm or so. These ceramic magnets would work well for this:
I’ve used these for a similar purpose and they stick great across a kettle wall. I did not have them touch liquid, however, and I doubt they are safe to use as-is in beer. Perhaps you can figure out a way to coat or cover the inside magnet so that it’s safe for beer. Maybe vacuum seal it in a ziploc bag?
Also make sure your kettle isn’t magnetic. Even if it’s labeled as 304 SS, depending on its quality it could still have some sticking power. It would suck if you removed the outside magnet only to have the hop bag still stuck to the inside surface.
magnets that are vacuum sealed in a food grade bag seem like a good idea.
Or just open the fermenter for 5 seconds and put your hops in
Definitely agree that there are far simpler ways to add dry hops. But if one is determined to do it with minimal O2 ingress, using magnets doesn’t seem any more complicated than the other methods.
I get minimal O2 ingress opening the fermenter for a few seconds. Gases don’t mix instantly. https://beerandwinejournal.com/can-co2-form-a-blanket/
You’re definitely preaching to the choir here. I dry hop the same way as you. That said, not opening the fermenter to add the dry hops would unquestionably add less O2 than opening fermenter. Does it matter? Absolutely not, AFAIC. But as we say, to each their own!
I add dry hops while there’s still yeast activity near the end of fermentation. As soon as I shut the lid and see CO2 from the airlock I figure I’m good. Besides, yeast is known to consume O2.
That initial airlock activity could be just off-gassing of CO2 because of the hops providing nucleation points for bubbles to form, rather than an indication of fermentation, so that alone may not be exactly the indicator you’re looking for. But I don’t think it’s a big concern anyways, because (as you mentioned) yeast consumes O2. Also, I can’t help but wonder if the “hop creep” phenomenon means that adding dry hops will kick off enough extra yeast activity to consume any potential small amounts of oxygen added during the dry-hopping process.
Something else I just though of. Unless the hop pellets are packaged in nitrogen from the manufacturer, there will be some O2 trapped inside the pellets. Opening the fermenter and dropping them in will most likely not cause any additional “real” O2 ingress that what is trapped in the pellets since there is a blanket of CO2 on the beer.
The magnet approach can be made to work, but there are definitely concerns about the materials involved. I came up with a similar approach using dental floss. A stainless weight goes in the bag with the hops which is tied with dental floss that is snaked out through one of the seals on the fermenter. Most seals can be tight even with the dental floss in place. The dental floss is used to hold the bag up out of the beer. When you want to drop your hops you loosen the seal a bit, jiggle the floss to loosen it, and let the weight pull the hops down. You can even pull them out of the beer a few days later, which you can’t do with a magnet. It takes some practice, especially if you can’t see what is going on inside.
Thinking about this a bit more, the magnets used for stir bars are covered in inert plastic. They can be sanitized and would be harmless to the beer if you could find a magnet on the outside strong enough to hold one up with a bag of hops attached.