Taste is pretty good here now that it’s had 3 weeks to condition fully, but I’m slightly underwhelmed by the lack of carbonation. There’s a hint of head, some very slight fizz on the tongue, but all said & done it’s not quite enough for a lager. I think next time we can increase it to 2g of Dextrose for those 330 ml bottles, maybe even 2.25g.
Pressure transfer to Cornelius Keg
The Fermzilla version of this one’s been cold-crashing for 3 days now, time to get it into a Corny keg. Standard setup this afternoon; brought the ready purged keg up to 9 PSI matching the Fermzilla, connected the Bouncer filter between the liquid out posts, popped the PRV on the keg to get things going before connecting the gas posts with a straight line. I left the Fermzilla in the fridge the whole time, and there was enough height difference to the keg for gravity to do it’s thing, filling it in around 20 minutes.
I’m not 100% convinced I need the Bouncer filter when doing a pressure transfer via the floating dip tube as that doesn’t really pick anything up, especially on a cold-crashed beer where everything’s well and truly dropped out. If anything, the Bouncer is a bit of a pain as it doesn’t handle pressure too well and is just one more thing to clean at the end of the day.
15 Lager Bottles
The 5 litres or so that I moved to the SS Brewtech Mini Bucket ahead of applying pressure to the Fermzilla has been bubbling very, very slowly while it’s sister vessel was cold-crashing, so I’m going to call time on this one and also put it away. This time I used Bag-Thing on top (but forgot to refill it) and added 1.5g of Dextrose to each of the 15 clear lager-style 330 ml bottles before filling those via the bottling wand and tube attached to the bucket’s lower spigot. I started out by also priming the first bottles with CO2 from the cylinder, but noted that on drawing out the wand I will have sucked air back in as the level went down, so I gave up on the CO2 figuring that there’s no finishing hops to be oxidised anyway, and that the reaction of beer on dextrose did produce some gas which had the caps lifting a little while they were waiting to be fixed.
Even though I kegged the Fermzilla first I set it aside before measuring OG, and instead bottled the SS bucket then measured OG there from the inch or so that was below the dip tube. The brew bucket came in at about 1.017 and when I got around to grabbing a sample from the Fermzilla’s collection jar I thought there was a discrepancy, because that weighed in at 1.019 to 1.020 – difficult to say due to carbonation. It soon dawned on me that I was seeing a difference because the Fermzilla was still at chiller temperature, so anywhere between 4 and 6℃. Plugging those values into Brewfather’s hydrometer temperature correction tool soon had my numbers lining up.
The controls were set for 2℃ approximately 24 hours ago and she’s now down to 4.8℃ and falling. Pressure has dropped from 20 to 15 PSI. At this rate she’ll spend the majority of the weekend just above freezing and get kegged on Monday.
SS Mini Bucket
I hope to have enough time to also bottle the contents of the mini bucket, assuming airlock activity has stopped by Monday. Probably won’t cold-crash this batch since she’ll have some time in the bottles to condition anyway, and I may well need the ferment fridge for my next batch.
The Fermzilla’s fermentation chart has been flatlining for a couple of days now with Tilt reading a steady 1.014 so I thought I’d grab a reading via the regular hydrometer before cold-crashing, and the news isn’t all that great: 1.020 @ 24.1℃ = 1.021. That should make for 4.9% ABV against a predicted 5.9% (and it tastes just fine) but I’m going to leave it just a little longer to see if we can drop a few more points towards the predicted 1.011. Might as well, bottling date isn’t for another 3 days according to Brewfather’s recipe.
SS Mini Bucket
Airlock activity has tailed off gradually since I racked 5 litres to my SS Brewtech Mini Bucket but there’s still some bubbles every few minutes, so I’m not going to worry about taking a gravity reading just yet. Besides, my expectation is that fermentation will be going on more slowly in the bucket, which isn’t under pressure and has been sitting around 4℃ cooler than the Fermzilla.
I have just over 25 litres of Vienna Lager in the Fermzilla, and because I don’t want to try bottling carbonated beer later on I’m moving 5 litres into my SS Brewtech Mini Bucket before increasing fermentation pressure in the Fermzilla to 20 PSI.
The idea is simple; gradually reduce pressure over a couple of hours right down to nothing, connect the beer out post to the bucket’s spigot, close the spunding valve and let fermentation push the brew out. I’m hoping that there’s enough yeast in suspension to keep the fermentation going without anything else needed, but if it looks like it’s stalled then I can always move some Krausen across later on as well, or just pitch more yeast. Gravity presently at 1.023 so we’re about 75% complete.
One thing was slightly weird; the hose connecting both vessels seemed to be pulling quite a lot of gas, even though both ends were fully submerged in the brew. I can only guess that this is CO2 being produced by the wort as its inside the tube, otherwise I’ve got a leak and a problem when it comes to kegging from the Fermzilla later on.
15 minutes later: the bucket’s airlock’s bubbling away happily, looks like my little Opshaug friend doesn’t mind his new environment. Pressure going up again gradually in the Fermzilla too – I didn’t want to add CO2 from the tank so as to increase pressure gradually because I’m concerned about the effects of all these changes on the Tilt.
Seeing some lovely Krausen on the brew tonight I couldn’t help but harvest some more yeast to add to yesterday’s bounty, which had settled down to a disappointingly paltry film at the bottom of its glass jar since I liberated it yesterday. Dropping the pressure briefly from 5 PSI to zero resulted in some bubbles rising to the top and also out of the dip-tube, so I can only hope the yeast and (more importantly) the Tilt Pro is happy being de- and re-pressurised so rapidly.
On refitting the spunding valve after cropping I took the opportunity to increase pressure to 10 PSI, based on positive feedback from others who have done the same with their Kveik.
With fermentation finally underway I wanted to have a go at top-cropping some yeast for the first time, and also start to apply a little pressure, just in case whatever’s caused my yeast to have such a delayed start might have further impact on the brew by producing off flavours. This is however supposed to be a malt-forward brew and I therefore don’t want to kill those esters altogether, so I’m going to leave it at 5 PSI for now.
On the cropping front I only managed to get a very small amount of yeast. David Heath reckons you’re supposed to steer clear of the FV sides and avoid any foam that’s turning dark brown, so all I managed to do is grab a very small amount from the middle of the Fermzilla’s foam hat. There isn’t enough to even think about using it for a serious brew, but I think I’ll play around a little bit and see how much I can grow it using a starter, maybe then add it to a kit brew instead of the included yeast.
As a parting note for tonight; I hope I haven’t killed fermentation by temporarily adding 10 PSI from the CO2 tank so that I could check the spunding valve was correctly set. Kveik is supposed to be as resistant to pressure as it is to temperature, but as soon as I swapped the airlock for a spunding valve the turbulence below the surface all but stopped. I’m sure it’ll be off again by morning …
I was fully expecting to have to restart with another yeast this morning, so it came as a pleasant surprise when I opened the ferment fridge and saw a good head of foam on Vienna. Checking the Tilt’s chart on Google Sheets (damn, forgot to ‘point’ that device at Brewfather) it appears as though we really only got going around 04:00 so with luck I’m just witnessing a delayed reaction to Kveik’s supernatural powers, and things will liven up from now on. If that’s the case then I can expect to be top-cropping some yeast by this afternoon. We’ll see.
Things are going so well in fact that I’m swapping the airlock out for a blow-off tube, ending in a bottle in a jug, just in case it gets even more lively. At least you can hear it now without having to open the fridge.
Another busy brew day from 07:00 to 14:30 today, starting my fourth ever all-grain brew and first ever Vienna Lager. Also using Kveik for the first time, specifically WLP518 Opshaug Ale Yeast. This time around I paid more attention to my vessel volumes at various stages and used the internal markings instead of a measuring jug to gauge initial fill. I’ve still not sussed out where I’m losing so much liquid but at least this time I waited until the end before adding more water to make up numbers, decanting just over two litres of cold tap water into the FV. Hope that’s not going to be a problem later …
Brew Day Notes
07:00 – Start heaters. Water was added last night to 28 litre mark using B40 internal scale, malt pipe fitted, chiller drained. All other pipes filled.
07:40 – Start dough-in
07:51 – Dough-in finished, but need to pat things down slightly to get all grains covered. Ready for 20 minute mash rest at 07:55, internal level reads 34 litres. Mash temp 60℃, MLT target temp 68℃.
08:15 – Rest finished, initial stir, levels now just below 34 litres. Nice consistency, slight foam building on stirring.
08:40 – First stir. Turn the centre pipe off while stirring so as to allow levels to equalise for first measurement. Looks like we’re about 33 litres now, so a loss of maybe 3/4 litre loss since mash start? Seems high – probably just slight level difference between inside and outside malt pipe. Mash temp after stirring is 69℃ in places, reducing MLT target to 65℃. Lid has been on for the whole mash (including rest) apart from occasional level checks.
09:00 – Second stir. Still looking good, levels slightly lower again after a few minutes with the centre pipe off – maybe 32.6 litres on the internal scale? Mash temp 65.1℃.
09:10 – 15 minutes left to run including mash-out, and since the liquid is flowing freely I’m not going to stir again. Previous sparges have been over too quickly for my liking, so I’m going to let the grain bed settle for the last 15 minutes and will try using aluminium foil on top with a couple of holes to distribute the sparge water flow evenly, ideally slowing it down in the process.
09:23 – starting to heat mash to 75℃. The mash tracker has stopped and offered a ‘continue’ button, so I guess I press that when I’ve reached target temperature. Heaters are in Mash (PID) mode so capped at 50% in case there’s grains to scorch the elements, but temperature is climbing very slowly.
09:34 – Taking too long, creeping up 0.1℃ at a time, currently at 70.4℃. Going full manual and increasing heaters to 60%. The pump is recirculating inside and outside, wort looks clear, hopefully anything in there won’t be scorching the heaters due to the extra 10%. Temp increasing slightly faster now. Maybe a neoprene jacket would help at times like this?
09:44 – Mash-out temp 75℃ reached, starting timer and reducing heat back to mash mode to see if it can actually hold this temperature. Noticed a change in foam with some lighter, bigger stuff being produced, probably as a result of the temperature increase. Protein?
09:48 – Halfway through mash-out, temperature holding just fine with heaters on auto and sitting at 20%. Mash temp perfect 75℃ – same as kettle. Wort wonderfully clear now.
09:54 – Mash-out complete. Turning off centre pipe in order to measure levels. 5 minute rest to equalise and I’m at 32.25 litres, having lost maybe 1.5 litres during mashing. SG is 1.047 at 60.9℃ but at 60.9℃ – equals 1.063. Getting ready to sparge.
10:15 – Tin foil deployed, starting sparge. Holes punched in using a fine pin make water distribution easier across the top of the grain bed, but I’m not happy with the slap-dash process of shaping two halves of tin foil – feels like it takes long time during which the grain bed is draining without new water being added, and I’m worried about the impact this will have when water does start to flow. One thing that tin foil does have going for it is the way you can adjust water distribution above the grain bed by pushing down in certain areas or adding more holes.
10:40 – Damn, forgot to time the exact finish of the sparge. Anyway, the grain bed has been draining and seems to have given up all its juice now. Internal scale reads 29 litres but to be fair that’s with the malt pipe raised, and previous measurements had it lowered. BF thinks I should be at 30.94 litres after sparging, so I’m two litres short. Gravity at 59℃ is 1.042 which equates to 1.057. Pre-boil gravity should be 1.051 so I think I can safely add 2 litres and re-measure, but I’m going to leave it until later and do a fermenter top-up instead.
10:50 – Malt pipe removed, steam hat and condenser fitted, heaters set to 100%. Currently at 68.8℃.
11:25 – Hot break came and went around 96℃ with quite a bit of foam. 60 minute additions are now in, boil timer running. Had enough time while approaching boil to empty and rinse the grain pipe and have a sandwich. Next stage is 15 minute boil additions in 38 minutes. Noticing for the first time a small amount of bubbles on the way to the pump. Is that normal?
11:48 – Still boiling just fine. I’m alternating between 65 and 70% heating power since that keeps things going without going too vigorous or stalling, so I should minimise boil-off while not getting a high-tide mark of hops that add little value. Opshaug Kveik has been warming to room temperature for about 90 minutes now, and I opened the packet and transferred it to a sanitised glass jar ahead of pitching.
12:07 – 15 minute addition Protafloc added. I also cut in the chiller for sanitisation (pumps paused, then heater to 100%) and judging from the difference in levels there’s about 2.25 litres in the chiller which I’ll recover at the end, but which I can’t measure for post-boil volume with the pumps off. Maybe should have done that before cutting the chiller in – can’t change much in 15 minutes thereafter. On a positive note, when the temperature briefly dropped as a result of adding the chiller the bubbles on the R/H tube also stopped, which means they’re a result of boiling rather than a leak of some kind.
12:11 – 10 minute additions are in; 2.5g yeast nutrient and 22g Hallertauer Mittelfrueh.
12:21 – End of boil, heater off, pump to 25% for a little whirlpool while things settle down enough to read the levels. Steam hat off and to one side, lid back on. Looks like we’re at 26.8 litres hot, plus the 2 litres in the chiller. Wow. This might call for a second FV. Let’s see how things look when I start to chill and transfer.
12:27 – Chiller on, pump to 25%. Tank temperature 95.1℃.
13:06 – Emptied into FV, 24 litres including scavenged contents from chiller. Post-boil gravity 1.062 / 21.6℃ = 1.062. BF was expecting 28.54 litres and 1.056, so I’m topping up the FV with 2 litres otherwise I’m looking at 7.2%! Added just over 2 litres, bringing volume to 25.5 and OG to 1.058. This will be 6.2% which isn’t too bad. Not sessionable, but not bad.
12:21 – added one level teaspoon Opshaug Kveik, just stirred it in as per David Heath video. Seems ridiculously small amount. Rest in jar back to the fridge, fit airlock and floating dip tube to Fermzilla, deploy blue Tilt. Once it’s at 50% attenuation I’ll top-crop some yeast and will swap the airlock for spunding valve.
14:30 – Clean-up finished. Not having aerated the wort today (didn’t seem necessary with so much foam) saved time as I had less to clean, CIP kit worked very well. Brew is in the ferment fridge wearing heat belt dialled to 25℃, presently it’s 21.5 and no signs of activity yet. Hope that was enough yeast, just doesn’t seem possible.
19:40 – Absolutely no activity yet. Isn’t Kveik supposed to be up for it from the word go? Double checked my quantities against the video, and yes, one shallow teaspoon does 25 – 30 litres of wort. So I’m adding another 1.5 teaspoons, just in case the yeast isn’t as healthy as that in David’s YouTube instructions.
23:00 – Still nothing. The new yeast has joined it’s sibling in the bottom of the Fermzilla’s trub jar. If it’s still the same by morning I’m racking to a new FV and pitching US-05. Reducing temperature by 1 degree in preparation … and the desperate hope that it might start something. Good night, Vienna.