Trading Oxidation for Infection?

Sometimes my hoppy beers have a slight off taste. I suspect oxidation, so I'm trying to limit exposure to air. However, I need to dry hop my IIPA in a secondary, because I need the primary for the next batch. I don't keg or have CO2, so I decided to run a blow off tube from the primary into a sealed container with an air lock of Star San. Another hose takes the CO2 (that has bubbled through the Star San) from the sealed container to an empty sanitized secondary carboy. I put some sanitized foil over the top of the secondary/hose to allow air to escape from the secondary, but keep infections out -- I hope.

When it is time to dry hop, I will remove the foil and use a funnel to add dry hops to the empty secondary, without removing the hose. Then I will disconnect the hose from the blow off container and connect it to the valve on my primary. Then I can rack through a hose that is filled with natural CO2 into a carboy that is filled with natural CO2/air, minimizing the exposure to air.

I may try to use a similar procedure with the bottling bucket -- filling it with natural CO2 from the next batch.

I'm sure this has been tried before. Successfully? Obviously, I am increasing the risk of infection. Worth it?

I've started wondering whether the Star San airlock has a purpose in this scenario. What do you think? Why not just run a blow off hose from the primary directly into the empty carboy?

One purpose is to see bubbling, I suppose.

If by off-taste, you mean metallic. Then it's probably oxidation. But since you bottle I'd think that's the least of your worries. Once you add that extra sugar and cap those things the oxygen gets absorbed by the cap and another dose of fermentation happens. I'd be willing to bet that your issue is temperature based and not an oxidation issue. Unless you constantly shake and stir your wort.

wbarber69 said:

If by off-taste, you mean metallic. Then it's probably oxidation. But since you bottle I'd think that's the least of your worries. Once you add that extra sugar and cap those things the oxygen gets absorbed by the cap and another dose of fermentation happens. I'd be willing to bet that your issue is temperature based and not an oxidation issue. Unless you constantly shake and stir your wort.

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Thank you for your comments. The off taste is quite subtle, but I don't get metallic. I am very careful not to agitate the wort post-fermentation, but I usually dry hop in a secondary, then transfer to a bottling bucket, and then bottle, so there is exposure to air/oxygen. I rigorously control fermentation temperature, so I don't think that is it. Also, I only notice this flavor in hoppy beers, and they all have been dry hopped. Now that I think about it, I don't remember if I got this flavor when I dry hopped in the primary. Better records would help! I will check for this next time.

If I can confirm that oxidation is the problem, I will buy a CO2 tank to fight it, but I will still bottle.

I suppose I could purposely oxidize the hell out of one baby bottle (12 oz) just to find out if it makes a difference.

Have you tried filtering... You bottle so I guess not. You may be tasting hop resins.

wbarber69 said:

Have you tried filtering... You bottle so I guess not. You may be tasting hop resins.

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I hadn't thought of that. No, I not only don't filter, but I let my hops roam free at all times. And "hop resins" does seem like a reasonable description of the taste. What would be a good way to check that? Maybe add a couple hop pellets to one of the bottles?

I have been doing some testing of my own, kinda, when it comes to this. I keg, so I normally filter before I go to keg if I have something with a lot of dry hops (I use leaf and they are allowed to float without a bag or tube or anything). But this runs the risk of infection. Since I need 2 empty sanitized and purged kegs to filter it gets a bit demanding. So I've been running some tests on a couple of batches here and there. I can say that when I don't filter I do get a slightly more earthy, kinda dirty grass taste, where the filtered brew is crisp and clean. But I'm also doing a couple other things along the way as well. Like doing all my fermenting and dry hopping in one vessel instead of using a secondary. Really I've been trying to see if my methods have been overkill up until now. While you do lose some flavor from filtering it definitely knocks out those resins. I came to this conclusion after a friend of mine randaled a DIPA a while back. I noticed that earthiness even more and was able to calculate that it must be the late (very late) addition of the hops. Since I could see the pollen floating in my glass, I assumed the resin was to blame. While I haven't done enough testing on the matter, I will joy discourage any methodology you can come up with to try to single out what it is that's affecting your beer. Most times I've found that my beers never taste right right out the gate, but after a couple weeks of aging I tend to be able to reassure myself that I didn't screw it up.

Another thing you could try other than filtering would be gelatin. You add like a teaspoon in some warm water, let it cool then add it to the wort before you cold crash allowing it to take hold of any proteins or solids left floating and drag them to the bottom with the cake. I've even seen it force whole leaf hops to the bottom before. It may be an easy step to take next time. It won't add any flavor or aroma and it's a method that's been used millions of times before with great results. Your lhbs should have some.

I proceeded as outlined in post #1, regarding racking into a carboy filed with natural CO2 for dry hopping. All went well. I decided not to try the same thing with the bottling bucket, so I will just risk a little oxidation during bottling.

This should be a good beer to try this method of dry hopping. With the high alcohol and loads of hops, I challenge a few stray bacteria to infect this beer. I'm sure it could happen, but I'm not worried.

When I bottle next weekend, I plan to purposely oxidize one bottle, and then oxidize it some more. I could zap it with pure O2, but that seems excessive. I'll just pour it back and forth into glass several times, with a lot of splashing and foaming. Then, I should be able to determine if the taste I'm getting is oxidation. If not, I'll move on to hop resin, I guess.

If a beer is significantly oxidized, it'll have a distinct taste of wet cardboard that gets worse over time.

BigFloyd said:

If a beer is significantly oxidized, it'll have a distinct taste of wet cardboard that gets worse over time.

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Yes, I have heard that, but I'm not sure I've tasted it or would recognize it. Also, maybe oxidized hops are a little different? I'm looking forward to ruining my beer (one bottle), so I will know how it tastes for sure.

Update: I am now drinking this beer. It was slow to carbonate (3 weeks). After about 5 days in the fridge, it is fair to partly cloudy. Hopefully it will continue to clear. It does not have the same off taste that most of my hoppy beers have, so that's nice. That doesn't prove that oxidation was the problem, of course. I still haven't tried the one bottle that I purposely oxidized. If it has the off taste, I may have learned something useful.

I don't think it is oxidation. Even going from primary to secondary, to the bottling bucket, I suspect something else. You taste it in hoppy beers so is it a fair assumption that you taste it in light beers only? Beers lacking any dark speciality grains?

How about your water? Have you used the same water source the entire time? If so, have you considered changing the source? Perhaps use bottled spring water one time and see if you get that flavor you're talking about.

Short of that, you could try dry-hopping in primary for 5-7 days and then bottling. I realize you want the vessel for the next batch, but can you delay it by a week just to see? If you don't get that flavor and you're good on the water, then I would go back to your idea regarding transferring with CO2. I just think it's not incredibly necessary. Then again, for all I know all of my beers have that weird taste and I've never noticed because I thought it was normal.

Tonight I tried the one bottle that I purposely oxidized. To oxidize it, I poured the finished beer back and forth between two glasses just before bottling. I poured vigorously for a few minutes and formed a nice froth in the glasses. Oops, I forgot to sanitize the glasses, but it turns out infections are a myth. Relax.

So what did oxidized beer taste like? In this case, it tasted like an IIPA. Hops, bitterness, and alcohol. Maybe a slight hint of an off taste, but maybe that was in my head. So oxidation is a myth too. Continue to relax.

I really didn't learn what I hoped, so I will try again with another beer. Maybe the flavor of this one was so over-the-top that I couldn't taste the oxidation. Or maybe I'm not the super-taster I thought I was.

Singletrack said:

Tonight I tried the one bottle that I purposely oxidized. To oxidize it, I poured the finished beer back and forth between two glasses just before bottling. I poured vigorously for a few minutes and formed a nice froth in the glasses. Oops, I forgot to sanitize the glasses, but it turns out infections are a myth. Relax.

So what did oxidized beer taste like? In this case, it tasted like an IIPA. Hops, bitterness, and alcohol. Maybe a slight hint of an off taste, but maybe that was in my head. So oxidation is a myth too. Continue to relax.

I really didn't learn what I hoped, so I will try again with another beer. Maybe the flavor of this one was so over-the-top that I couldn't taste the oxidation. Or maybe I'm not the super-taster I thought I was.

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Neither infections nor oxidation are myths. Both can happen. Infections require some conditions that may not have been present in your experiment. Oxidation isn't quick. If you try this again, leave that beer in the bottle for 2 or 3 months and then sample it. You may find out why you shouldn't oxidize beer then.

I guess I needed smileys after the "myth" statements.
Yes, next time I will wait longer to try the ox beer. But if it really takes a few months, then I have less worry with hoppy beers, because I work hard to drink them fresh.

Oxidation and stale reactions take place quicker at warmer temperatures. I have been dry hopping my pales right in primary with 2oz of loose pellets at the tail end of primary fermentation Day 5/6 and normally keg at day 10/11. Firestone walkers brewer says this method allows the yeast to transform some of the compounds into the aromas we enjoy. For bigger beers, I tend to do 2oz in primary and a secondary dose in the keg bagged.

The wet cardboard description is odd to me because I never tasted that in my many years. I think descriptor comes from hot side aeration with malt oxidation. With west coast hoppy beers they just taste muddled and stale vegetable. Leave an ipa out in a glass over night, tastes terrible but never wet cardboard.

I have also found not all hops are created equal. Columbus/CTZ perfect example, so much variation on aromas with that hop. At times I have gone crazy switching/checking my process, then go onto a new batch of hops and boom incredible beer, then a few months onto another bag of hops and meh batch. I find buying in bulk at the start of harvest will at least allow you to identify that particular crop/farm version of that varietal for the year. Adjust your recipes as needed after a sample brew, this is what the pro breweries do instead of randomly buying Columbus throughout the year from various suppliers.