Tips For Minimizing Oxygen (O2) Ingress When Brewing Juicy, Hazy IPA’s
By Shung Chieh
Recently, like many of you, I’ve started brewing juicy, hazy/New England style IPA’s. For whatever reason, the first two times I tried the style, the results were great where the beer was golden, with fragrant bouquet and bright, hop-forward taste. But after that initial success, I went through a series of batches where the results have been inconsistent and never quite as good as the first two tries. I think part of this is because I started brewing hazy IPA’s just before the pandemic, and since there wasn’t much beer on hand, the results were tasted quickly and batches were quickly consumed 😁. Later however, during the pandemic, the length of time between brewing and consumption increased significantly since there was more beer than I could drink (until I started sharing it). There were tell-tale signs of oxidation (beer is more brownish than golden, and at times the taste was more like wet cardboard, rather than bright, with strong citrus and tropical flavors and nose).
So, in an effort to regain the quality of the early results, I’ve made a conscious effort to reduce oxygen ingress at all the key steps, but especially during the introduction of dry-hopping. After following some suggestions on the internet (thanks especially to https://homebrewfinds.com!) I ended up at the following process:
I perform primary fermentation in a SS Brewtech brewbucket and resort to dry-hopping via a Corny keg. The brewbucket isn’t specifically needed – the key is that the primary fermentation vessel support a low-O2 transfer to a Corny keg. For example, I also have a Spiedel fermenter which I modified to support low-O2 transfer.
After primary fermentation (usually 3 days), I perform a gravity or pressure transfer from the brewbucket to a keg. My process is similar to this article, except that I use this ball lock post stuck into a stopper which I put into the bucket.
Here are two photos:
One of the unexpected things I found is that the transfer can take a while (sometimes 30 minutes). I think the post can get clogged, and a few times I need to resort to a small low 1-2 psi hit from CO2 to restart the transfer or speed it up.
The next important improvement came from switching to dry-hopping in the Corny keg. I often use a keg as a secondary fermenter, but previously, I was dry-hopping in the primary fermenter. Unfortunately, however, I inevitably introduced O2 when I added the hops in primary with my simple setup.
To dry-hop in the keg, I put my hops in the following canister, and connect it using hooks to connect the chain to a keg lid with a tab and also to connect the chain to the loop on the canister. I also modified the keg to use a floating dip tube, so that I can transfer more “clear” beer from the top to the serving keg (or if I’m lazy, just serve from this fermentation keg). I load up the hops in the hop filter canister, make sure the lid is twisted on tight (I had it come undone once, and that makes a sludgy mess at the bottom of the keg), and put the lid onto an empty keg. .Then I purge/vent the keg 5 times with CO2, and on the last time, fill it with CO2 with just a few psi. Then I hook up the brewbucket to the keg and perform a gravity transfer per steps 2 and 3.
Here’s a photo of the keg lid with hop canister:
While in the “fermentation” keg, I use a spunding valve (I especially like this duotight version although I also have a home-made one based on this) to vent CO2 produced during the fermentation. I usually set it to vent at 3-5psi. Some recipes call for 3 days of dry-hopping, but I usually dry-hop for a week, sometimes two.
A side note regarding hopping in whirlpool during the cooling of the wort:
I use a standard hop spider. It took me a while to learn that it’s the temperature that matters (and time), rather than a “physical/mechanical” whirlpool that matters. So, I’m careful to allocate sufficient time, at the right temperature (~160-180F, 20+min) when it comes to whirlpooling the hops. Yes, I swirl the cooling wort for a short while for the other reasons to whirlpool, but don’t spend as much time doing it as I did early on when I was still learning.
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