Avoiding oxidation during dry hopping

[worlddivides]

I know this topic has come up a bazillion times so far, and I've read tons and tons of articles online about it, but I still don't really have an answer.

In the past I never really worried much about oxidation because all of my fermenters had very small openings on the top (whether glass or plastic carboys or a plastic fermenter with several ways to open it with the smallest opening being in the top), but since pretty much everyone seemed to agree that a cheap bucket fermenter is just as good as an expensive fermenter, I decided to go with bucket fermenters for the first time in my life. But the worry I have now is that, instead of a very small opening like in carboys, the opening is the entire size of the bucket lid (the opening for the airlock is too small to push hop bags through - it's big enough for various kinds of airlocks, but not big enough for a bung). I can't recall ever having oxidization in a hoppy beer I've made, but I also had that really small opening on all the fermenters I've used before now.

I've noticed a lot of yeast companies and homebrewers and craft brewers talking about adding dry hops during active fermentation to take advantage of biotransformation, with NEIPAs seeming to dry hop the earliest, whereas other styles dry hop near the end of fermentation but while it's still ongoing. Personally, I've never dry hopped during fermentation, generally dry hopping from around Day 11 to Day 14. Most places also say that you should only dry hop for 2-3 days and no more than 4 days. But if I did that, I would need to keg the beer earlier than 2 weeks in the fermenter. For stouts, brown ales, saisons, and various other styles, I'll leave the beer in the fermenter for 2-3 weeks (longer if it's high ABV or something special like a sour or something with a secondary or even tertiary fermentation), but for IPAs and just hoppy beers in general, I want the hops to be as fresh as possible, so I don't really want to package after 2 weeks. But at the same time, I've always believed that I should give the yeast enough time to clean up before bottling or kegging.

So this brings me to the dilemma. Dry hop at the end of fermentation for 2-4 days, then just keg the beer quite a bit ahead of 2 weeks? Or dry hop around Day 10 or 11 and keg on Day 14 but have the risk of oxidation?

I don't think there is any one clear answer on this and, while I've read a ton about the subject online, I'm just as unsure about what to do, so I was hoping to hear some opinions. I do know there are some people out there who keg really hoppy beers at 1 week and quite a few who dry hop in the keg (though I do kind of worry about that since it could mean the beer being in contact with the hops not just longer than 3 to 4 days, but for say a month or two and I also worry about what it could do for clarity, even with me adding gelatin to the keg before transferring the beer on top of it).

Apprecaite any input!

 

[day_trippr]

fwiw, on some hazy IPAs I used to do a round of "biotransformation" dry hops 2 days post pitch, followed by another round once fermentation had completed and the FG was steady over two successive readings, and that round would sit for four days, before cold crashing for a couple/few days then kegging. Others I skipped the "bio hops" completely, and did either one or two rounds post-fermentation.

But since the beginning of 2024 I have held off dry hopping until the FG is stable, then I do a two day "soft crash" to 50°F, then dry hop for just two days, then hard crash to 36°F for two days, and then keg, both for neipas and wcipas. But I don't just drop the pellets in, because at 50°F they go straight to the bottom and sit there largely undisturbed, especially the really dense pellets (bt/dt). So I pulverize the pellets in a Cuisinart and pour that in.

I ferment in 6.5g Italian glass and have to be quick about adding the hops, and I'll do a perfunctory CO2 flush of the head space afterwards just for grins. Surely makes the conical folks with their CO2-purgeable hop droppers cringe But, the rest of my handling is pretty tight, and I routinely keep kegs of the haziest IPAs around for as long as 5 months and they're still excellent, so I'm good with what I'm working with...

[edit] wrt the bucket, that's definitely a major challenge if removing the lid is required. Given how many folks use buckets for fermentation I wonder if someone has come up with a practical hop dropper that could be fitted to an appropriate size hole in the lid? Doesn't seem like it'd require a ton of work if one uses PVC fittings...

Cheers!

 

[worlddivides]

fwiw, on some hazy IPAs I used to do a round of "biotransformation" dry hops 2 days post pitch, followed by another round once fermentation had completed and the FG was steady over two successive readings, and that round would sit for four days, before cold crashing for a couple/few days then kegging. Others I skipped the "bio hops" completely, and did either one or two rounds post-fermentation.

But since the beginning of 2024 I have held off dry hopping until the FG is stable, then I do a two day "soft crash" to 50°F, then dry hop for just two days, then hard crash to 36°F for two days, and then keg, both for neipas and wcipas. But I don't just drop the pellets in, because at 50°F they go straight to the bottom and sit there largely undisturbed, especially the really dense pellets (bt/dt). So I pulverize the pellets in a Cuisinart and pour that in.

I ferment in 6.5g Italian glass and have to be quick about adding the hops, and I'll do a perfunctory CO2 flush of the head space afterwards just for grins. Surely makes the conical folks with their CO2-purgeable hop droppers cringe But, the rest of my handling is pretty tight, and I routinely keep kegs of the haziest IPAs around for as long as 5 months and they're still excellent, so I'm good with what I'm working with...

Cheers!

Thanks. That's some pretty good data. I've generally heard that it's better to not dry hop "too cold," but the definition of "too cold" isn't often defined. I've generally assumed they mean to dry hop at regular fermentation temps and not fridge temps (i.e. 60s and 70s as opposed to 30s and 40s). I think the pellets falling to the bottom at colder temps is probably one of the reasons for this advice. I'd never thought of pulverizing the pellets, though I know that when Cryo hops were first introduced, they were sold as a powder.

I have seen mixed reactions to the biotransformation, while personally I'm just more worried about oxidation.

I'm thinking of maybe just slightly lifting the fermenter lid on one side, then pushing the bags of hops in and quickly closing the lid. I'm sure some amount of oxygen would still get in that way. While I know how to purge kegs, I'm not sure how to purge fermenters.

In the old days, I had some bottled double IPAs (six or seven different hops with massive dry hopping) that still tasted great several months later, so I'm honestly just worrying about something I've never had in any of my beers before just because I never considered the risk of oxidation. On the positive side, I can transfer the beer from the fermenter to the keg via a spigot in the fermenter.

I've never added Campden tablets when bottling or kegging, but I'm starting to consider it as an option just to reduce the risk of oxidation further.

 

[day_trippr]

I would use caution if considering the use of SMB at kegging, because if you don't get the amount right, there can be a sulphurous character left behind. Ascorbic Acid has no similar down-side...

Cheers!

 

[worlddivides]

I would use caution if considering the use of SMB at kegging, because if you don't get the amount right, there can be a sulphurous character left behind. Ascorbic Acid has no similar down-side...

Cheers!

Yeah, I've never used it outside of getting rid of chlorine and chloramine before the mash, so I do feel a bit hesitant to try adding it during kegging.

To be honest, I think I'll just try to avoid oxygen as best as possible and not use it and only consider using it in the future if there's any perceptible oxidation in this beer. I don't have any ascorbic acid on hand, but it does seem a better option in this case.

 

[Miraculix]

Why not just add a bit of sugar together with the dry hops?

 

[worlddivides]

Why not just add a bit of sugar together with the dry hops?

That idea did cross my mind, I think, because you mentioned it in another thread.

I'd imagine it's enough sugar to create CO2 to fill the headspace and push out any oxygen, but not enough to increase the ABV any more than, say, 0.1% or so. Is there any established principle for it? For example, 1 gram of table sugar per gallon of beer?

 

[IslandLizard]

Being a fervent bucket fermenter, I've drilled a 1" access hole in a few bucket lids "opposite" the airlock hole,* using a 1" hole saw and then a piece of very fine sandpaper around a thick dowel to smooth the edge. They fit standard 1" bungs, creating a good seal. I can even pressurize the headspace a bit, the lid will bulge somewhat.

When dry hopping, I blow CO2 in through the airlock hole at around 10 psi, while adding the hops (commando style, not bagged**) through the 1" access hole counterstream. Then purge the headspace a few times for good measure.

* At the time I avoided drilling through the lettering on the lid, so my placement was not arbitrary.
As time passed I've concluded there are better areas for the hole. One would be truly opposite the airlock hole and perhaps somewhat closer to the outer edge. Reason: farther away from the "input hole" may actually provide better or more complete purge characteristics.
I also use that access hole to gently stir the dry hopped beer a couple times during dry hopping. For that I use the back end of a long plastic brew spoon, which has a little paddle. All done against a counterstream of CO2 of course, followed by a few "swollen lid" purges. In that light, the current distance of the hole from the center of the lid works well. Or perhaps placing it halfway to the edge.

** I think I get quicker and better extraction putting the hops in loose vs. bagged. IIRC, Scott Janish also recommends against bagging. I've never done any comparisons.

 

[Miraculix]

That idea did cross my mind, I think, because you mentioned it in another thread.

I'd imagine it's enough sugar to create CO2 to fill the headspace and push out any oxygen, but not enough to increase the ABV any more than, say, 0.1% or so. Is there any established principle for it? For example, 1 gram of table sugar per gallon of beer?

Just throw in two or three hand full. I guess about 50gram or something like that.

 

[worlddivides]

Being a fervent bucket fermenter, I've drilled a 1" access hole in a few bucket lids "opposite" the airlock hole,* using a 1" hole saw and then a piece of very fine sandpaper around a thick dowel to smooth the edge. They fit standard 1" bungs, creating a good seal. I can even pressurize the headspace a bit, the lid will bulge somewhat.

When dry hopping, I blow CO2 in through the airlock hole at around 10 psi, while adding the hops (commando style, not bagged**) through the 1" access hole counterstream. Then purge the headspace a few times for good measure.

* At the time I avoided drilling through the lettering on the lid, so my placement was not arbitrary.
As time passed I've concluded there are better areas for the hole. One would be truly opposite the airlock hole and perhaps somewhat closer to the outer edge. Reason: farther away from the "input hole" may actually provide better or more complete purge characteristics.
I also use that access hole to gently stir the dry hopped beer a couple times during dry hopping. For that I use the back end of a long plastic brew spoon, which has a little paddle. All done against a counterstream of CO2 of course, followed by a few "swollen lid" purges. In that light, the current distance of the hole from the center of the lid works well. Or perhaps placing it halfway to the edge.

** I think I get quicker and better extraction putting the hops in loose vs. bagged. IIRC, Scott Janish also recommends against bagging. I've never done any comparisons.

View attachment 854317

Really appreciate the detailed explanation and the pic. My airlock hole is also about as small as yours, so not really big enough to put hops in. Since my current batch is currently fermenting, I'm thinking Miraculix's idea might be the best one for this current batch.

I've always dry hopped in hop bags, both with pellets and whole hops, mainly because it's easier to clean up and I've always assumed the extraction was roughly the same either way, but if the extraction really is better just thrown directly in there, then I might have to try it "commando style" too. Are there any drawbacks?

 

[worlddivides]

Just throw in two or three hand full. I guess about 50gram or something like that.

50 grams seems a bit much, but it does give me a better idea. I just checked Brewers Friend and 50 grams of table sugar would increase the ABV by 0.2%, whereas 25 grams would increase the ABV by 0.1%. Maybe I'll shoot for 25-35 grams then. Granted, a 0.2% ABV increase isn't a lot, but I'm trying to keep it at the line where it creates enough CO2 while changing the ABV as little as possible.

 

[Miraculix]

50 grams seems a bit much, but it does give me a better idea. I just checked Brewers Friend and 50 grams of table sugar would increase the ABV by 0.2%, whereas 25 grams would increase the ABV by 0.1%. Maybe I'll shoot for 25-35 grams then. Granted, a 0.2% ABV increase isn't a lot, but I'm trying to keep it at the line where it creates enough CO2 while changing the ABV as little as possible.

This should do it as well. If you're really conscious about it, you could probably lower the fg a little bit next time to compensate for the late sugar addition.

 

[IslandLizard]

I've always dry hopped in hop bags, both with pellets and whole hops, mainly because it's easier to clean up and I've always assumed the extraction was roughly the same either way, but if the extraction really is better just thrown directly in there, then I might have to try it "commando style" too. Are there any drawbacks?

I don't know for sure if loose hops give better extraction than bagged hops as long as the bagged hops have plenty of room to expand, so the beer can fully permeate the bag. IIRC, count on at least 4 times expansion of the volume of the added dry hop pellets.
I do think agitation speeds up extraction, and probably more so when the hops are bagged: Diffusion is a slow process!

By agitating (stirring) 2-3 times during the dry hop I hope for quicker and better (more complete) extraction. The dry hops are only in there for 2-4 days. I then cold crash for 2-4 days, using a CO2 filled mylar balloon on the airlock shaft, to prevent air from sucking back in.

By that time all hop (pellet) pulp has sunk to the bottom, together with the yeast.

I then siphon the clear beer (using a pre-primed racking cane with 4-5 feet of tubing attached) from above the trub into a 100% liquid pre-purged keg. Toward the end of the transfer I tilt the bucket toward the side where the siphon is mounted to, keeping the siphoning well deep. Then pull the liquid QD off the keg as soon as I see cloudy beer going into the tubing.

Here's a link to Scott Janish' article on Dry Hop Recommendations:
https://scottjanish.com/dry-hop-bes...s-a-guide-for-process-and-recipe-development/
There's a downloadable PDF on the bottom of the (yellow) abstract.

 

[worlddivides]

Appreciate all the info. I'm thinking I'll use Miraculix's sugar idea and your "commando" dry hops. I've never tried it before, but I guess I don't see any reason not to, especially if it gets quicker and better extraction (at the very least, it'll be a nice way to test it out for myself). Cold crashing before transferring should also help significantly reduce the amount of hops that get transferred.

 

[IslandLizard]

Appreciate all the info. I'm thinking I'll use Miraculix's sugar idea and your "commando" dry hops. I've never tried it before, but I guess I don't see any reason not to, especially if it gets quicker and better extraction (at the very least, it'll be a nice way to test it out for myself).

Yeah, give it a try!

I guess this may be difficult or impossible for you to do right now, but want to mention it for the future:
Janish recommends doing a soft (cold) crash for 1-2 days to drop most of the yeast, before adding the dry hops. The beer is kept at that cool temp during the dry hop time, then cold crashed to drop everything.

 

[worlddivides]

Yeah, give it a try!

I guess this may be difficult or impossible for you to do right now, but want to mention it for the future:
Janish recommends doing a soft (cold) crash for 1-2 days to drop most of the yeast, before adding the dry hops. The beer is kept at that cool temp during the dry hop time, then cold crashed to drop everything.

That's actually possible for me to do now, either by adding more ice bottles around my fermenter to lower it from where it is now (64F or so) to around 56F or by sticking the fermenter in the fridge, though that would eventually lower the temp into the 40s. If I remember correctly, Janish recommends... mid to upper 50s, I think? I read about it a while back, but I don't remember the exact details. I think the idea was that a slightly colder dry hop had more pleasant flavor extraction? I mean, I probably should just click on the link you posted and refresh myself on the details. Though I suppose you might have meant it's not possible for me now because if I dropped it too low, my yeast would stop fermenting the sugar I want to refill the headspace with CO2.

 

[IslandLizard]

Yeah, I didn't know you had the capabilities to cool the fermenter with beer and keep it at that lower temp for a few days. using ice bottles. And then cold crash to low 40 or 30s.

I presume you've got other things in your fridge that need to stay cold, so that option is out until you're ready for the cold crash, and keg it.

Keep in mind, neither soft crash nor cold crash are imperative. Beer will clarify on its own at any temp, when it's done fermenting, given a few days to a week (or 2) depending on the yeast used.

Though I suppose you might have meant it's not possible for me now because if I dropped it too low, my yeast would stop fermenting the sugar I want to refill the headspace with CO2.

Glad you remembered and reminded me!
Soft crashing would be the wrong thing to do if you want to add sugar to start a slow referment after adding dry hops, hoping to consume any redissolved O2 and possibly purge O2 from the headspace.

Instead, you can add dry hops at the end of fermentation, while it's slowing down. Although I'm not sure if any newly introduced dissolved oxygen will be consumed, since there's no new yeast growth to be expected at that point. It will merely start purging the gasses in the headspace, including any oxygen that entered along with the hops.

How are you going to add your dry hops? Once I became aware of oxygen risks in late fermentation, I started pushing hop pellets through the airlock hole in the lid (removed the grommet first).

Hop flowers can be added that way too, but they will likely float, which is not good either. A weighed-down bag would still be best for those, IMO. And do it when fermentation is still somewhat active.

 

[worlddivides]

Yeah, I didn't know you had the capabilities to cool the fermenter with beer and keep it at that lower temp for a few days. using ice bottles. And then cold crash to low 40 or 30s.

I presume you've got other things in your fridge that need to stay cold, so that option is out until you're ready for the cold crash, and keg it.

Keep in mind, neither soft crash nor cold crash are imperative. Beer will clarify on its own at any temp, when it's done fermenting, given a few days to a week (or 2) depending on the yeast used.


Glad you remembered and reminded me!
Soft crashing would be the wrong thing to do if you want to add sugar to start a slow referment after adding dry hops, hoping to consume any redissolved O2 and possibly purge O2 from the headspace.

Instead, you can add dry hops at the end of fermentation, while it's slowing down. Although I'm not sure if any newly introduced dissolved oxygen will be consumed, since there's no new yeast growth to be expected at that point. It will merely start purging the gasses in the headspace, including any oxygen that entered along with the hops.

How are you going to add your dry hops? Once I became aware of oxygen risks in late fermentation, I started pushing hop pellets through the airlock hole in the lid (removed the grommet first).

Hop flowers can be added that way too, but they will likely float, which is not good either. A weighed-down bag would still be best for those, IMO. And do it when fermentation is still somewhat active.

Since I don't have a way to get one of the Cool Brewing insulated bags I used when I lived in the US (I really love those things), I ended up buying the biggest food delivery insulated bag I could find, which is big enough to fit a 5 gallon fermenter, though I cannot zip it shut with the airlock attached (I could if there was no airlock), so I used velcro insulated sheets to cover the entire area around the airlock, so it effectively keeps all the coolness inside without letting practically any heat inside. I thought it would be effective, but I'm honestly surprised at just how effective it is. I turn off the AC before I go to sleep and when I wake up in the morning, it's in the mid 80s around the insulated bag, but the fermenter itself is at 64 and the ice still isn't completely melted (it's at that point that I switch out new ice bottles and turn on the AC).

I'm kind of going overboard with trying to clarify the beer. I used half a whirlfloc tablet, plan to cold crash, and also plan to add gelatin upon kegging. It's part of the reason why I'm not really worried about the addition of loose pellet hops messing with the clarity (whirlfloc was something I just kind of bought on instinct since I always used it before I learned about gelatin).

I have considered adding at the end of fermentation, but I only want to dry hop for 3 days, maybe 4 at the most.

I'm thinking of just lifting the lid a little bit on one end and just quickly pouring the hops from the vacuum-sealed bags immediately, then closing it back up. I thought the airlock hole might be too small, but to be honest, most pellets would probably fit in there, but that would take a lot more time because I'd probably have to add them one or two at a time. The airlock hole is also probably too small for my funnel to fit in there, so crushing the pellets and adding them as a powder probably isn't a great idea, though I suppose crushing them and then pouring them from the vacuum-sealed bags might work.

When I used to add whole hops, I would also add 2-3 sanitized marbles to the hop bag to weigh it down, and I always felt that worked pretty nicely.

 

[SkyPilot]

What about placing a weldless TC port on the lid? Then you could use one of the hopbong kits with it, or just dump them in the larger opening more quickly.
Would be heavy during the addition process so you would need to be careful not to over stress the lid. Might want/need to add a large dia plate on top/under lid to distribute the load.

 

[HM-2]

If you are soft crashing I would strongly advise against the sugar method. The last thing you want to do is throw extra fermentables in when the yeast is cold and precipitated out then let the temp rise back up during the DH. That's a recipe for restarting fermentation and in the worst case getting a tonne of diac.

Some people on here swear by pulverising hops into a powder with a blender or nutribullet and pouring that in, which'll work with a much smaller hole than pellets.

 

[Miraculix]

If you are soft crashing I would strongly advise against the sugar method. The last thing you want to do is throw extra fermentables in when the yeast is cold and precipitated out then let the temp rise back up during the DH. That's a recipe for restarting fermentation and in the worst case getting a tonne of diac.

Some people on here swear by pulverising hops into a powder with a blender or nutribullet and pouring that in, which'll work with a much smaller hole than pellets.

I agree, the sugar method should never be aplied on the colder side. This is something that needs to be finished before temperature is being lowered.

 

[worlddivides]

If you are soft crashing I would strongly advise against the sugar method. The last thing you want to do is throw extra fermentables in when the yeast is cold and precipitated out then let the temp rise back up during the DH. That's a recipe for restarting fermentation and in the worst case getting a tonne of diac.

Some people on here swear by pulverising hops into a powder with a blender or nutribullet and pouring that in, which'll work with a much smaller hole than pellets.

Yeah, I already mentioned that (in my response to Island Lizard). Definitely don't plan to do them both since they wouldn't be possible to do at the same time, considering my yeast would likely go dormant in the 50s. And despite what Janish and some others have said about cold-side dry hopping, it really is a subjective thing. Brulosophy did one of their ExBeeriments a while back comparing dry hopping in the 30s and dry hopping at fermentation temps (I think it was 70 or 71), and the testers were able to reliably tell a difference, but more of them preferred the taste of the "warm dry hopped" beer. Although there does seem to be a consensus on dry hopping for 2-4 days as opposed to 7-14 days (though there are some major breweries that do very long dry hopping with great results), there seems to be less of a consensus on cold vs. warm dry hopping.

I intend to do cold crashing after dry hopping is finished and when I'm ready to package.

 

[DVCNick]

I've tried to do the cold crashing before dry hopping to drop the yeast out, then warm it back up to dry hop.
What I've seen is that dumping the dry hops in causes a lot of C02 to come out of solution, stirring the entire thing up, and seemingly eliminating any benefit that might have been gained with the cold crash.

Are people using fermenters with trub-dumping capability and doing that prior to dry hopping after crashing?

 

[HM-2]

Are people using fermenters with trub-dumping capability and doing that prior to dry hopping after crashing?

In my case yes, when I can. I have one fermenter that lets me dump trub and one that doesn't.

 

[shavy]

Appreciate all the info. I'm thinking I'll use Miraculix's sugar idea and your "commando" dry hops. I've never tried it before, but I guess I don't see any reason not to, especially if it gets quicker and better extraction (at the very least, it'll be a nice way to test it out for myself). Cold crashing before transferring should also help significantly reduce the amount of hops that get transferred.

Have you seen this thread:
https://www.homebrewtalk.com/threads/dry-hop-questions-using-magnets.727698/post-10271832

 

[worlddivides]

Have you seen this thread:
https://www.homebrewtalk.com/threads/dry-hop-questions-using-magnets.727698/post-10271832

I had not. It's definitely an interesting idea. It won't work for this batch, but I can keep it in mind for the future.

 

[worlddivides]

I'd also imagine that a closed transfer from the fermenter into a CO2 purged keg would be a great way to avoid oxidation, but I'm not sure how much of the liquid in the fermenter will be able to be transferred into the keg and I worry what will be the case if there's more liquid in the fermenter than can be transferred into the keg, so I'm thinking I'll just transfer via silicon tubing to the bottom of the keg with the lid open (maybe with sanitized saran wrap covering the opening except the tubing), much like how I used to transfer the contents of the fermenter into a bottling bucket with priming sugar already in it. For reference, I have a 3 gallon keg, but I have 3.4 gallons in the fermenter. I knew that a decent amount of that would end up as trub and also get absorbed in dry hopping, so I might lose 0.2 to 0.5 gallons, but I kind of worry if I try to transfer the contents of the fermenter via a closed transfer and there are actually 3.1 gallons transferred over (or even 3 gallons exactly). I have to imagine this isn't a unique problem. Especially if someone has a 5 gallon keg and they fermented 6 or 6.5 gallons.

 

[SkyPilot]

……. kind of worry if I try to transfer the contents of the fermenter via a closed transfer and there are actually 3.1 gallons transferred over (or even 3 gallons exactly). I have to imagine this isn't a unique problem. Especially if someone has a 5 gallon keg and they fermented 6 or 6.5 gallons.

If I understand your concern correctly this works pretty well for me so far

https://www.kegland.com.au/products/duotight-flow-stopper-automatic-keg-filler

 

[worlddivides]

If I understand your concern correctly this works pretty well for me so far

https://www.kegland.com.au/products/duotight-flow-stopper-automatic-keg-filler

I do think it totally would, but I have no idea how I would get ahold of that in Japan.

 

[mac_1103]

I'd also imagine that a closed transfer from the fermenter into a CO2 purged keg would be a great way to avoid oxidation,

It's the best way to avoid oxidation.

but I'm not sure how much of the liquid in the fermenter will be able to be transferred into the keg and I worry what will be the case if there's more liquid in the fermenter than can be transferred into the keg,

Are you worried about overfilling the keg or are you worried about what to do with the beer that doesn't fit? It's easy to avoid overfilling the keg with a scale or a product like the one linked in post #28. Any leftover beer can just get bottled directly with priming sugar or transferred to a PET soda bottle and carbonated with one of these.