Saturday, 30 July 2016

Sour Session IPA (kettle-soured, fermented with Brett)

Shortly after brewing my first kettle-soured beer (a Gose, half dry-hopped with Citra, the other half with fresh lime zest), I've been keen on doing another beer with the same technique. The souring-with-Lactobacillus-sourced-from-L. plantarum-capsules approach worked fairly well the first time; while the pH didn't get QUITE as low as I would have liked, the process was relatively painless, with no purging of oxygen necessary, and lower temps for souring required (compared to using Lacto from grains, or even a direct, commercial pitch). I also have quite a few capsules left, so I might as well put them to use, no?

It was easy to pick what to brew next using this method - I've been a big fan of hoppy sours since I first tried Funky Gold Amarillo by Prairie Artisan Ales last year. What a fantastic beer: the perfect level of sourness, big tropical fruit hop character... just amazing. Hoppy sours are now the next big thing, with many commercial breweries releasing their own iterations. Most of these are quick-soured with Lactobacillus, which makes sense; if you want to focus on hops, you don't want a beer to take months to sour properly. Mind you, the dry hop is really the big thing here, as high bitterness in a beer from large early-boil additions doesn't really work in a sour - the flavours can clash in a big way.

I have to be honest here, and admit that I did not set out to brew a "Sour Session IPA". My original plan was to have something in the 6% ABV range, which is around where most of the hoppy sours out there seem to finish. More on that later. But to start off, I used the exact same grist that I have used for my Brett IPAs (most recently, an Azacca single-hopped beer fermented with Brett brux Trois Vrai), simply because I wasn't looking for something complicated, and this one has worked well in the past. Mostly 2-row and Wheat malt, it has a bit of Carapils and Acid malt as well, and that's it. I was looking for a very pale beer, here, and this gets you in the area of 4 SRM, which I thought was perfect. I mashed at 153 F to give the beer a bit of body, since I was pretty sure I'd be fermenting with Brett after souring.

From what I can tell, most hoppy sours are dry-hopped, and have very little - if any - hops added before fermentation is complete. As I mentioned, high bitterness apparently doesn't work in a beer like this, but I still wanted to get as most hop flavour and aroma in this beer as I could. I finally decided on adding no hops during the boil, but I did end up doing two large additions after the propane was turned off: a 20-minute steep, and more once the immersion chiller began chilling. I chose Columbus (CTZ) and Hallertau Blanc, two varieties that I really enjoy but don't get used as much as I'd like. My thoughts were that the two together would give a nice mix of dank, tropical, pineapple characters. Even with a total of 6 oz between the two being used, the calculated IBUs only came to around 10 (in contrast, Funky Gold Amarillo is listed as having 18 IBUs).

I had way too many ideas of what I wanted to use for the dry-hop additions, and finally decided that my best option here was to split the batch after boiled and chilled, so I could ferment the wort separately and dry-hop with two different varieties. I chose two of my favourite American hop varieties right now: Equinox, a quite-new hop that is very unique ("lime, lemon, papaya, green pepper"), and Citra. And I don't really have to say anything about Citra at this point, do I?

The process I used to sour my wort was the same as I used for my Gose. I made a 1 L, 1.040 DME starter and chilled it to 100 F, then opened and pitched in 5 plantarum capsules. This time, however, I added a very small amount (~0.5 mL) of phosphoric acid to the starter before emptying in the capsules, to bring the pH down to ~5, and give it a head start. Now, I left the flask on a heating pad like the first time, which kept the temperature at 95 F or so. After a couple of days, the pH was only down to 3.85, and I started getting discouraged. However, I decided to leave it a while longer since I wasn't in a hurry. The next morning, my wife inadvertantly unplugged the heating pad while I was at work all day; I didn't notice till I got home, and plugged it back in. The next morning I checked the pH again, and it had dropped to 3.21! Maybe unplugging the heating pad had nothing to do with it, but I'm wondering if maybe L. plantarum works better at room temperature than it does in the 90s? Research by others indicates it should work plenty fine at 95 F, and that it doesn't start having issues until you get above 110 F. Whatever the reason, it seemed to work better this time compared to when I used the same method for the Gose. Maybe the phosphoric acid-induced push had something to do with it?

So I mashed, sparged, vorlaufed, etc. as usual, to a little over 5.5 gallons, heated it all to a boil and chilled it down to 100 F. At this point, I gradually added small amounts (1 mL at a time) of phosphoric acid until the wort pH had reached ~4.5. Lowering the wort pH to 4.5-4.8 has been shown to aid in preventing foam degradation (check out a detailed explanation on the Milk the Funk Lacto Wiki here). The wort was then transferred into a Better Bottle, where I then pitched the Lacto starter. Instead of immediately turning on a heat pad and attaching a heat belt, I waited until the temp got down to the 80s F, and then switched on the pad and belt, which kept the temp in the high 80s. After several days, the pH was down to 3.3 (and tasting sour), which surprised me again, as this was quite lower than I had got to with the Gose, at 3.69. Obviously I got to a better place with the starter this time around, and it worked very well considering the temp never got above 85-86 F.

I continued on, bringing the soured wort to a boil for 5 minutes, then cut the propane and threw in the first hop addition for a 20-minute steep. Once I started chilling, the second addition went in (smelling delicious, by the way), and I chilled it all down to about 64 F. The batch was split into two 3-gallon Better Bottles, both aerated for 45 seconds with pure O2, and then the Brett starter was pitched in an equal volume into both, at 66 F. The OG came in lower than planned, at 1.053, but I wasn't too concerned (or surprised, since my efficiency has been lower than normal lately, and using a good portion of Wheat malt never helps it).

Both beers were undergoing active fermentation by the next morning, and slowed down very quickly, with virtually no airlock activity by the following evening.. Now, the temperature didn't get that warm (maybe 72-74 F at its peak), but I had no reason to be concerned; I checked on the beers regularly, as is my practice, and didn't notice any major spikes or drops in temperature. However, when I took a gravity reading a few days after pitching, it was only at 1.020! D'oh! But I thought, hey, it's Brett, maybe it needs some more time, but alas, after another week the gravity hadn't budged. So, I was forced with deciding whether to give it more time (which didn't seem like it would help), pitching another yeast to hopefully drop it more, or just go ahead and dry-hop it. I went with option #3, and re-classified this beer as a "Sour Session IPA". What I was worried about, however, was bottling this beer. Any beer at 1.020 would make you worry about bottle bombs somewhere down the line, but a 1.020 beer with Brett in it? Exactly.

Ultimately, I kegged one half (Equinox) and bottled the other (Citra), adding sugar to aim for only 2 vol CO2, as opposed to the 2.5 I would normally go with. And when the beer seemed carbed after 5 days, I put as many bottles as I could into the fridge, which was a good thing because this beer is now DEFINITELY carbed to higher than 2 vol; probably closer to 3, in fact!

But how do the two beers taste? There's a lot of similarities between them, but ultimately the Citra dry-hopped half comes out on top. Thankfully, neither tastes sweet to me, which was obviously a worry with the high FG (as an aside, I think this strain may just need extra time; a friend had a beer finish at 1.020 as well, and after leaving it on pineapple for an additional month, found the FG had dropped to 1.005).There's something in the Equinox beer that I can only describe as slightly... clashing. For some reason, the bitterness in this beer - despite only having a calculated IBUs of 10 - feels too high. Not sure if it's the Equinox (can't see it), the dry-hop addition being slightly larger than the Citra half (maybe?), or if I simply got more bitterness out of the steep than I calculated (but that doesn't make sense, because the Citra half had the same steep).

On the plus side, the sourness is pretty much right where I want it. Definitely enough for you to know this is a sour beer, but not TOO mouth-puckering. Nice hop presence, lots of fruit, with the Citra beer being somewhat brighter, without the slightly-harsh finish of the Equinox. The body is smooth, but not overly-full (a worry with that 1.020 FG) and it certainly doesn't taste too sweet.

So, I'm calling this one a success, with room for improvement. For a re-brew, I'd use a less-finicky Brett strain, and cut back on the flameout hop addition; maybe halve it and go from there. Otherwise, a good brew to have on hand for this season, and further proof that souring with Lacto plantarum capsules works!

Recipe Targets: (5.5 gallons, 75% efficiency) OG 1.057, FG ~1.014, IBU ~10, SRM 4.1, ABV ~5.8%

3.7 kg (71.8%) Canadian 2-row
1.1 kg (21.4%) Wheat malt
200 g (3.9%) Carapils
150 g (2.9%) Acid malt

CTZ - 49 g @ 0 min (with a 20 min hop steep)
Hallertau Blanc - 35 g @ 0 min (with a 20 min hop steep)

CTZ - 49 g @ 0 min (after started chilling)
Hallertau Blanc - 35 g @ 0 min (after started chilling)

Citra - 48 g dry-hop for 5 days (1/2 the batch, in primary)
Equinox - 70 g dry-hop for 5 days (1/2 the batch, in primary)

Misc: 1/2 tab Irish Moss at 5 min

Bacteria/Yeast: Lactobacillus plantarum capsules (5) in a 1 L starter; after souring, wort fermented with WLP648 Brett brux Trois Vrai (with a starter, ~200 billion cells)

Water: Fredericton city water, carbon-filtered; 5 g Gypsum and 5 g calcium chloride added to mash

- Brewed on May 24th, 2016, by myself. 50-minute mash with 15 L of strike water; mash temp on target of 153 F. Mashed-out for 10 minutes with 6.75 L of boiling water to 167 F. Sparged with ~2.5 gallons of 168 F water for final volume of ~5.75 gallons. Heated to a brief boil, then chilled down to 100 F. Added ~4 mL phosphoric acid till wort pH was 4.5, then pitched Lacto starter.

- 26/5/16 - pH reading of 3.31; moved BB to back room of garage where temp was in the low 60s F, until I was able to complete the brew.

- 31/5/16 - 5-minute boil. Final volume ~5.5 gallons; OG low at 1.053. Chilled to 64 F, then split the batch into two 3-gallon Better Bottles. Aerated with 45 seconds of pure O2 per fermentor, pitched yeast starter at 66 F.

- Fermentation going strong by the next morning, very strong in the evening, but visibly slowing by the next morning. Several days later, gravity was reading 1.020. A week later, no change. Added dry hops to the Equinox half and kegged it four days later; waited a few extra days for the Citra half, then bottled after a four-day dry hop, aiming for 2 vol CO2.

Appearance: Both pour with a moderate-sized, white head that, despite the low pH, shows quite good retention. Body is yellow-coloured, with a fair amount of haze.

Aroma: Very big and bright, for both beers, like sour orange juice. 

Taste: More sour orange juice, but the Equinox beer has a slightly-harsh, tinny aftertaste that takes away from the positives. The Citra, meanwhile, all gels together very well and is quite refreshing.

Mouthfeel: Medium-bodied, creamy. Equinox beer, being kegged, has moderate carbonation, while the bottled Citra half is higher, as I had expected; effervescent.

Overall: Citra wins, and I don't know why! 

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