Tag Archives: WLP518

Oct 202128Thu

The Opshaug starter was more or less ready to go so I took a gravity reading and threw it in. A thin film of foam almost coated the top of the bucket and there was an audible hissing as soon as the lid came off. Gravity (before pitching) came in at 1.039 making for just 0.5% ABV from the natural yeast, so still plenty of sugar there for the Kveik to get stuck into. Can’t wait to see how this turns out.

Sep 202112Sun

Sunday, 15:00

I used a tiny amount of harvested Opshaug that’s been in the fridge for an age, and if this works I’ll frankly be amazed. There can’t have been more than a tenth of a packet, so I plugged 0.05 packs into Brewfather’s starter calc and it recommended 1.5 litres of water with 150g DME. Threw in some Lipohop and plenty of yeast nutrients and hoped for the best.

Monday, 08:30

Nothing happening, so I’m switching off the stir plate to give her a chance to gather her thoughts.

Monday, 11:00

I’m halfway through brew day and the yeast starter still looks dormant apart from some isolated bubbles rising at the edge, so I switched on the stir plate again in case she needs more oxygen. The effect was immediate, with enough bubbles coming from the bottom of the flask to form a good head, which started filling up the neck straight away. So there’s definitely something happening, but I’m not sure I’ll reach high Krausen by the time I’m ready to pitch in a couple of hours. Keep the wort ready in the FV until this evening? This will be interesting!

Monday, 21:00

The starter has been bubbling away on the stir-plate for most of the day, increasing whenever shaken and slowing down when left, but it’s the gradual change in colour from dark, russety brown to a light, warm toffee hue that convinced me to pitch this now. Or maybe it was the sentiment it’s Kveik, innit?

Jun 202120Sun

Both the Opshaug Pale and Bure Gold that I’m brewing with my resident Opshaug Kveik are still fermenting when they should have finished out a couple of days ago, though to be fair the trend graphs provided by Tilt Pro are now beginning to flatten out a little so I’m looking forward to getting both of these put away in the coming week.

I don’t pay attention to the absolute values reported by Tilt, but I think it’s safe to say that both of these brews are going to be way stronger than they’re supposed to be; Bure Gold should be around 4.3% (previous efforts were 4.3 and 4.2%) and Tilt thinks we’re nearer 4.6% right now, Opshaug Pale was aiming for 5.3% in the recipe (5.9% adjusted for actuals) and I’m presently in the neighbourhood of 6.7%.

The only negative aspect of this continued fermentation is that my finishing hops will have had their contribution diminished a little due to the production and venting of CO2, but there’s nothing I can do about that now other than record what’s happened and adjust subsequent brews using this yeast accordingly.

#wisdom: I’m not sure if it’s a trait of WLP518 or the way I’ve harvested / re-used it, but my Opshaug Kveik has not started as furiously as expected, and taken much longer to ferment. If the Opshaug Pale turns out well then let’s repeat it, but dry-hop much later.

Jun 202110Thu

It’s just under 24 hours since fermentation started properly (approx. 36 hours after pitching) and we’re halfway towards FG, which means the yeast is at its healthiest point and ripe for harvesting. I used a glass jar and small ladle, both sanitised using boiling water. Pressure was reduced gradually over the space of about 15 minutes, and although the top of the Krausen had receded slightly from its high-tide mark on the bottom of the lid, when the pressure started dropping it reared up again and a small amount was ejected into the waiting blow-off bottle. This may not have been needed if it wasn’t for the top-cropping, but having it doesn’t hurt. Removing the Fermzilla’s top cap was predictably messy and I ended up washing it and the blow-off tube before sanitising and refitting afterwards.

#wisdom: don’t bother fitting the floating dip-tube to the lid if planning to harvest yeast, as it’s just in the way and one more thing that needs cleaning. Instead fit it when replacing the lid after top-cropping.

#wisdom: using a bigger mason jar for the yeast is recommended, since it’s really just foam at this point and compacts down to nothing when it’s chilled.

Jun 202109Wed

As per my previous experience with Opshaug, nothing happened when I first pitched last night after dropping the temperature down to an acceptable level, and nothing continued to happen for around 12 hours.

Wednesday, 09:22 (P+12)

This morning I finally saw some signs of life; a slight movement on the spunding valve gauge, some bubbles on the side of the Tilt, and some gunk floating on the surface. I’m not sure if this is part of the hot break / other protein deposits or if it’s some of the yeast resurfacing from its sugary slumber, but there are some clear areas on the lower slopes of the Fermzilla now.

Looks like we’re off!!

Wednesday, 11:22 (P+15)

Things are really going now, with foam islands linking up and growing almost as I watch. Pressure climbed to 8 PSI in 3 hours just now and I’m dialling it back down to 5 now that I’ve got enough feedback on the spunding valve. I’m also increasing temperature to 27℃ since most sources suggest Opshaug is happy between 25 and 35℃. Can’t wait to see what this looks like by late afternoon.

Wednesday, 17:22 (P+21)

Houston, we have liftoff. Even from outside the ferment fridge I can hear the spunding valve, sounding like a punctured tyre. The pressure has crept up again to just over 8 PSI and again I’m knocking it back down slightly because I want to top-crop some yeast when she reaches 50% attenuation. Reducing it wholesale at that point will probably stress the yeast and my Tilt as well, so it’s a question of keeping an eye on it and reducing gently, ideally stopping around 5 PSI, though now I’m slightly concerned that the increase in temperature and relatively low fermentation pressure will result in Krausen breaching the vessel and getting into my spunding valve, so I may inline a spare 5 litre keg for safety. Hell, at this rate I might just use the gas being produced to prep some kegs by filling them with sanitiser and then driving it out, rather than doing it later with cylinder gas.

Spunding Valve on Opshaug Pale, 21 hours after pitching

Wednesday, 22:22 (P+26)

One day and one hour after pitching unleashing this monster I’ve had to fit a two litre blow-off tank in the name of safety, lest we should wake up and discover that Opshaug Kveik has consumed not just my spunding valve, but our entire world. The beige, foamy mass is mere millimetres away from conquering the recently provided 2 litre bottle and shows no sign of slowing down. Attenuation sits at 31% so with a bit of luck I’ll be able to harvest nearer 50% at some point in the morning, unless this thing kills us during the night. Sweet dreams!

Jun 202105Sat

Kicked off the second of two kits that I purchased towards the start of the year, and unlike the other one this is will be kegged and enjoyed rather than given away. I’m also using it as a test bed for some top-cropped WLP518 Opshaug that was liberated from Good Night Vienna on 26th May.

The brew was started in the usual way according to instructions, adding 3.5 litres of boiling water to the contents of both tins, which were then rinsed out by half-filling with more boiling water. A teaspoon of Wilko’s yeast nutrient was also chucked in at this stage. Adding 3 five litre bottles of Tesco Ashbeck with semi-frozen slush brought the temperature of the 25 litre SS Brewtech bucket down to 20.2℃ at which point I pitched a small heaped teaspoon of yeast from a jar that had been allowed to almost get up to room temperature for approximately 40 minutes from the refrigerator. OG came in at 1.047, so slightly higher than my previous two runs at this brew which were both at 1.044.

May 202127Thu

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.

May 202126Wed

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.

Good Night Vienna (GNV) at 19 hours into Primary

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.

May 202125Tue

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 …

Vital Statistics from Brewfather

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.

Sparging with Tin Foil Hat

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.

Pitched Yeast

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.

From David Heath’s Kveik User Guide

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.

Vienna Lager, 7 hours after pitching Kveik