Wyeast 1469 - injection of pure O2 after 18 hours?

[Gadjobrinus]

Thinking of trying something new, which is that rather than manually rousing the Wyeast 1469 over the first 24 hours, doing a few short bursts of O2 through the oxygenator. This, over a method I recall from @cire of plunging a heat-sanitized spoon through the krausen cap and lifting it up high to splash and aerate (more problematic here, as it's a simple, narrow/tall plastic bucket....imagine I'd be splashing a lot outside the bucket and potentially inviting infection; v. a large, shallow, square s/s vessel I then had).

What do you think?

 

[rmr9]

You could try it, fairly certain they spray the yeast back on top over in Yorkshire so I guess this is just kinda adding air in the opposite direction.

My best experience involved simply pushing the yeast cap back down (after scooping the dark gunk on day 1) with a spoon and doing a gentle stir. It wasn’t too hard and didn’t have any contamination issues. Thats what I would do - and will do - whenever I use 1469

 

[DBhomebrew]

Yeah, it's not just about the oxygen. Stir up that cap. While you're at it, harvest some of the cap for another batch. I found batches of 1469 to be progressively better when brewed in immediate succession.

 

[rmr9]

I’d like to think doing it that way, pushing the cap back down helps the yeast attenuate more since I got really good attenuation that way. Could just be guessing though.

 

[Gadjobrinus]

Thanks guys, makes much more sense. At 18 hrs, only traces of a krausen developing but roused nevertheless and will do it every 12 hours until seeing good, strong krausen. DB, thanks for reminding me on the top cropping. I'd forgotten I used to do that - after initial krausen and its crud, skimming and discard, then skimming some for later use into sterilized quart jars, boiled/cooled DI water on top. Just can't recall how I estimated the density/volume and therefore yeast population in the jar, for repitching. Agree re-pitched yeast is better than first-time, though can't recall how many generations I did before starting over (actually, used to start from slants, every __ generations).

Anyone has a method to parse how much yeast we gather, by density, etc., in the capture jar? I have a vague memory of @cire describing his method, perhaps on another site, so perhaps he'll see this and chime in.

 

[cire]

There's nothing scientific about my method, but it uses a sanitized spoon with no oxygen. A starter of a pint at least is pitched into a 5 gallon brew and yeast harvested from that brew can be enough for up to a 15 US gallon brew.

Usually there will be a covering 12 hours from pitching, sometimes not very thick, occasionally trying to escape. I usually brew in the afternoon, so pitch and aerate by paddle late evening, and as soon as there is a full covering, it will be returned into the wort. I usually rouse three or four more times that day. A typical 1040 wort reaches peak fermentation from 24 to 36 hours from pitching, when it can be harvested to leave a thing covering for protection. Once rousing is stopped, the fermentation rate is dramatically reduced.

I simply pitch all the yeast collected from the previous brew. If too much is pitched, the surplus is quickly removed and saved it for the next brew. My vessel capacities are almost double that of the brew and kept open until fermentation begins to slow, else the heat trapped in the top of the vessel makes the yeast become hyperactive.

 

[Gadjobrinus]

There's nothing scientific about my method, but it uses a sanitized spoon with no oxygen. A starter of a pint at least is pitched into a 5 gallon brew and yeast harvested from that brew can be enough for up to a 15 US gallon brew.

Usually there will be a covering 12 hours from pitching, sometimes not very thick, occasionally trying to escape. I usually brew in the afternoon, so pitch and aerate by paddle late evening, and as soon as there is a full covering, it will be returned into the wort. I usually rouse three or four more times that day. A typical 1040 wort reaches peak fermentation from 24 to 36 hours from pitching, when it can be harvested to leave a thing covering for protection. Once rousing is stopped, the fermentation rate is dramatically reduced.

I simply pitch all the yeast collected from the previous brew. If too much is pitched, the surplus is quickly removed and saved it for the next brew. My vessel capacities are almost double that of the brew and kept open until fermentation begins to slow, else the heat trapped in the top of the vessel makes the yeast become hyperactive.

I thought I'd seen somewhere this notion of harvesting the yeast then keeping it cold under a cold DI water blanket until wanting it for the next batch. Also, a way to guesstimate by yeast cake volume your total no. of cells. Somewhere else, apparently.

Great, thanks for the info Eric. So I oxygenated at pitch, yesterday 16:30, roused this morning at pitch + 18 hours, and on returning from work tonight, thick krausen was well established, and I roused again. I was thinking of rousing one more time (this evening) - that would be a total of 3 rousings, then. Then as of tomorrow skimming, discarding brown bits, taking middle layer of yeast and leaving a thinnish cap of foam. No plan to set under an airlock, merely lidded (plastic bucket) as it is now.

Sound reasonable? Any suggested changes?

Also, mind telling me what you use for your fermentor - material, I mean. Unfortunately I got rid of a nice s/s square vessel with a tri-clover port, so just thinking of getting a very simple s/s vat, thin gauged steel.

Which brings up a final point. What do you or anyone think of transferring the wort tonight, "final rousing," by vigorously pouring/splashing from the fermenting bucket into my 10-gallon, s/s stockpot (BK)? And then it would be the final fermentor? This would be pitch + 28 hours or so.

 

[cire]

No real science from me, I've read how it might be done, but find it unnecessary at my scale, plus the relative unimportance of time compared to a commercial production facility. Yesterday I'd intended to cask last Wednesday's brew, but circumstances meant it didn't happen until this morning.

When harvesting yeast, I add a spoon or two of wort for cover. I rouse as frequently as commitments allow until the yeast begins to level off or decline. If collected later, there will be less to harvest, and if necessary, some of the top layer of yeast will be added after racking.

I don't have to skim the first covering of yeast as I use whole hops and have a filter in the bottom of the kettle. After the wort is chilled, hops settle over the filter and just recycling a litre or two, the hops make a perfect filter for clear wort. I have 3 SS cylindrical FVs of 50, 0 and 100 litre capacity. They have loose fitting lids which are fitted after the brew until clear is finished and then after the yeast is harvested.

I can only suggest you find what works best for you. Top fermenting yeasts ferment very slowly unless roused. Once the yeast is harvested, fermentation continues at a slow pace and the wort will be seen to be comparatively clear. Real Yorkshire yeasts are not like Burton yeasts, which benefit from double drop and the Burton Union systems. Burton yeasts continue to ferment and, for example, will bottle condition more quickly than Yorkshire yeasts do. Just cool the wort when a couple of points from final gravity and the yeast will mostly drop out after a few days, leaving enough for conditioning at cellar temperature.

 

[Gadjobrinus]

Thanks Cire. So, your rousing - I seem to recall some notes from @McKnuckle indicating "they" [might have been Black Sheep?] rouse every few hours for several minutes, over 3 days." I'm at hour 36.

By:

I rouse as frequently as commitments allow until the yeast begins to level off or decline.

Do you continue to rouse during your first few days - in other words, so long as yeast is exhibiting growth/krausen redevelops, you keep rousing, until you see evidence (is it by the krausen thickness/density, however we measure it) it is starting to fall back? Just don't want to move from proper rousing to over-aerating the wort like crazy.

I'd love to go to whole hops and a filter bed like you have, but it's hard enough to find English hops regularly in pellets, in my experience. So, I do have to skim the brown crud. Presuming that, and I skim a layer beneath for harvesting - do you harvest during the entirety of your rousing schedule, or do you take a one-time harvest, whether you end up with 6 or 15 rousings?

 

[cire]

Black Sheep have cylindrical stainless steel fermenting vessels, a sort of Yorkshire Square. Black Sheep have a fixed regime for consistency and production requirements, which I don't. My fermentations last 2,3 or 4 days, during which the yeast will be harvested in a single operation. The temperature is allowed to free rise, but when it is cold in the brewery, that is aided by manual intervention. Once the yeast has been harvested at peak activity, the temperature is maintained until gravity approaches that of racking, when the fermented wort is cooled to reduce the quantity present at transfer. I will usually rack the beer after 6, 7 or 8 days after brewing, longer for high gravity beers. My beers are generally in the region of 4% ABV.

All the above has been derived over time for my brewing system and way of living, no more scientific than that. Once the yeast has been harvested, it is necessary to confirm that I have chosen the best point in the cycle and act appropriately. If done too early the yeast may need to be roused again to achieve further attenuation, if too late you may not get a covering to protect the wort during cooling and up to racking. In commercial breweries they will have a regime for each different brew. For a known fixed regime for your brewery, it will likely be necessary to settle on a particular brew with repeated testing until finding what will in future always work. I simply read what the yeast head is telling and take a gravity reading if in doubt. When a Yorkshire yeast isn't roused, fermentation will soon come to a virtual stop.

I rouse when I can and obviously don't when I can't, rousing has to fit into other aspects of daily activities. I will rouse as I go out for whatever reason and again upon return. If there is a long gap between those, fermentation will be limited.

 

[Gadjobrinus]

Black Sheep have cylindrical stainless steel fermenting vessels, a sort of Yorkshire Square. Black Sheep have a fixed regime for consistency and production requirements, which I don't. My fermentations last 2,3 or 4 days, during which the yeast will be harvested in a single operation. The temperature is allowed to free rise, but when it is cold in the brewery, that is aided by manual intervention. Once the yeast has been harvested at peak activity, the temperature is maintained until gravity approaches that of racking, when the fermented wort is cooled to reduce the quantity present at transfer. I will usually rack the beer after 6, 7 or 8 days after brewing, longer for high gravity beers. My beers are generally in the region of 4% ABV.

All the above has been derived over time for my brewing system and way of living, no more scientific than that. Once the yeast has been harvested, it is necessary to confirm that I have chosen the best point in the cycle and act appropriately. If done too early the yeast may need to be roused again to achieve further attenuation, if too late you may not get a covering to protect the wort during cooling and up to racking. In commercial breweries they will have a regime for each different brew. For a known fixed regime for your brewery, it will likely be necessary to settle on a particular brew with repeated testing until finding what will in future always work. I simply read what the yeast head is telling and take a gravity reading if in doubt. When a Yorkshire yeast isn't roused, fermentation will soon come to a virtual stop.

I rouse when I can and obviously don't when I can't, rousing has to fit into other aspects of daily activities. I will rouse as I go out for whatever reason and again upon return. If there is a long gap between those, fermentation will be limited.

Fantastic. Thanks for the generous thoughts, cire.

 

[Gadjobrinus]

48 hours in. I've roused several times per day, and anticipate perhaps one more day. Skimmed and discarded last night, and I harvested earlier today.