First time liquid yeast

[Poochops]

Hi all, I'm planning brewing a big big beer at the weekend and I'm using liquid yeast for the first time (well, second, the actual first time 9 months was a disaster that stalled 2/3 of the way finished) I've got myself a fresh pack of wyeast Belgian abbaye II with a manufacture date of 5th December 17 and am about to make a starter.
OG should be 1.096/8 and the brewers friend calculator says I need over 700b cells! It also says that two 2l steps will only get me in the mid 400s. I think this will be plenty personally but does anyone know any better?
What I plan is to pitch a 2l starter and brew it out, then crash, decant, and add 2l more wort, brew, crash and decant again then pitch the slurry, have I got this right? Should I do a third? I was planning on brewing Sunday then storing in my no chill cubes till the yeast was ready but depending on the replies I might be best waiting till next week.
Thanks

 

[Zephyr259]

Using the calculator here, it says you need 402 billion cells for 23 L at 1.098. Do you have a stir plate? Based on the yeast's age it looks like a 2L starter at 1.040 will get you 380 billion, if you can nudge it up to 2.15 L then you're good in one step. These figures assume a stir plate, without one it's going to take 3 stages.

 

[IainM]

I think this will be plenty personally but does anyone know any better?
What I plan is to pitch a 2l starter and brew it out, then crash, decant, and add 2l more wort, brew, crash and decant again then pitch the slurry, have I got this right? Should I do a third?

I'm putting a triple with similar gravity on week after next and this is exactly what I plan to do. I think two 2L starters should be fine, as you have fresh yeast to begin with. If you put it on now then it will probably be finished and ready to crash in 24-36 hours. The second starter will finish a lot quicker. You might be ok with one 2L starter but personally I wouldn't risk it as I've had a couple of high gravity beers not turn out so great after skimping on the pitching rate.

It is probably worth noting that Belgian breweries don't pitch at as high a rate as American brewers, which is what the Brewer's Friend calculator uses for high gravity beers. I'd suggest scrolling down and reading the 'pitching rates', 'finding the balance' and 'key variables (revisited)' sections on Stan Hieronymous' article about brewing Belgian beers. From this, I would suggest really aerating the wort and possibly doing a second aeration after 6-12h, to compensate for the pitching rate.

 

[Poochops]

Ta both of you, I thought the pitch rate seemed extremely high you've kind of confirmed what I thought, i pitched it last night and it's go going fine, it had a good shake this morning and it'll be getting a good few more when I pass.
Now, is chill, decant, add more wort desirable, or alternatively I could add 2l of 1.080 wort to give me 4l of 1.040 in total for the second step? This would save a day or two crashing (in my head at least), its in a 5l water bottle.
Cheers

 

[IainM]

Ta both of you, I thought the pitch rate seemed extremely high you've kind of confirmed what I thought, i pitched it last night and it's go going fine, it had a good shake this morning and it'll be getting a good few more when I pass.
Now, is chill, decant, add more wort desirable, or alternatively I could add 2l of 1.080 wort to give me 4l of 1.040 in total for the second step? This would save a day or two crashing (in my head at least), its in a 5l water bottle.
Cheers

I'm not sure. The second 4L starter would have about 2.3% abv from the get-go and end up over 6% abv, which intuitively I guess wouldn't be great for what the goal of making a starter is: having the healthiest yeast possible. That said, people do do it so it is probably ok.

 

[Zephyr259]

I've done both, normally given time to properly crash the first starter and decant I'll do that, but I often don't want to wait the extra time. However, I tend to do a small then big starter based on inoculation rates. For example my barley wine (15 L at 1.90) needed 240 billion cells. My stored yeast was a bit old and it was a small overbuild I'd kept so the first starter was only 400 mls, followed by a 1.5L to get me to the full cell count. For the 2nd starter I made 1.1 L of wort using the DME required for 1.5L and added that to the first batch. My volumes seems way off for some reason so I topped up with some boiled water. Worked fine, starter went off like a rocket and so did the beer it got pitched into.

According to the notes, the yeast growth is based on the amount of extract in the starter,

Spoiler: Maths

All growth rate data comes from the work done by Kai Troester of Braukaiser fame. My original intent was to include both the Braukaiser and Mr. Malty calculations, and allow users to pick from both. However, the more I delved into the subject, the more convinced I became that the Troester figures were more reliable. Troester makes his formulae freely available, while the Mr. Malty formulae are treated like something of a trade secret. Troester has published data from multiple experiments that seems to indicate repeatable results to back up his assertions, whereas I can't really find any experiments to back up (or back into) the Mr. Malty figures.

Specifically, the growth equations used in this calculator are, as follows:

- For stirred starters, if the initial cell count is less than 1.4 billion per gram of extract, the growth rate is 1.4 billion cells per gram of extract.
If the initial cell count is between 1.4 billion and 3.5 billion per gram of extract, the growth rate is 2.33 - (.67 * initial cells) billion cells per gram of extract.
If the initial cell count is greater than 3.5 billion per gram of extract, there is no growth.
- For simple (non agitated starters), the growth rate is .4 billion cells per gram of extract, up to an inoculation rate of 3.5 billion cells per gram of extract. If you exceed this, there is no growth.
- For shaken starters, the growth rate is .62 billion cells per gram of extract, up to an inoculation rate of 3.5 billion cells per gram of extract. If you exceed this, there is no growth.

The formulae for stirred and simple starters comes from the article linked below detailing estimating yeast growth rates, and the formula for shaken starters comes from the 2013 NHC presentation also linked below.

most starters are going to grow 1.4 billion cells per gram of extract used, which means doing a 4L at 1.040 is going to grow a huge amount of yeast (up to 616 billion cells).

 

[Poochops]

I'm not sure. The second 4L starter would have about 2.3% abv from the get-go and end up over 6% abv, which intuitively I guess wouldn't be great for what the goal of making a starter is: having the healthiest yeast possible. That said, people do do it so it is probably ok.

I hadn't considered that to be fair, and I do want to save some back for a future starter so it probably warrants the cold crash in that case. Reading the link you posted (very interesting, thanks) I'm now thinking it might be better to pitch the lower end anyway. I'm allowing myself to be convinced by this quote

"At American microbreweries, the usual pitching rate is 1 million cells of yeast per milliliter of wort per degrees Plato (cells/mL/°P). (One degree Plato is roughly equivalent to 4 gravity “points” on the specific gravity scale.)

Common advice for homebrewers calls for boosting the pitching rate by 50% for higher gravity beers. In contrast, Westmalle pitches 5–6 million cells per milliliter for its 19.6 °P (1.081) Westmalle Tripel — just over 0.25 million cells/mL/°P."

that 1 million cells per ml per degree is a failsafe rather than necessarily always desirable. Only time will tell I guess.

 

[Poochops]

most starters are going to grow 1.4 billion cells per gram of extract used, which means doing a 4L at 1.040 is going to grow a huge amount of yeast (up to 616 billion cells).

Thanks for the explanation and I'm probably going to cold crash it now, but see in that spoiler though, it says shaken starters produce 0.67 billion cells per gram, so am I right in thinking 2l should make 134 billion, plus the original 74 billion viable cells in the pack = 208, then when I pitch that into another 2l I'll make it up to 208+134 = 342 billion? Or am I missing something?

 

[Zephyr259]

No problem, you maths looks right based on 200g of extract. If you like the results from liquid yeast I'd recommend you look into building a stir plate, as seen in the maths, they just over double the amount of yeast you can grow in each step.

In reference to pitching rates, I go with 0.75 for ales and it's been fine, I did use the recommended 1.5 rate for my bock, that was a pain to grow up, if i start doing high gravity lagers frequently then I'm going to have to look into getting a 5L flask.

 

[Poochops]

Nice one, thanks again, I have all the bits for a stir plate came today as it happens, little time waster for tomorrow! I have a 2l flask from my first disaster with liquid yeast but I'm a great deal more to grips with brewing nowadays so it's time to get back in the driving seat.

 

[Zephyr259]

Ah, cool cool. A 2 L flask does most things, for my recent barley wine I grew 300 billion cells from 9 billion in 2 starters (the 0.4 / 1.5 mentioned above). It helps that I brew 15 L batches, going up to 23L would stress the starter volumes a bit. I've had a couple of 1.5L starters push foam out the top and get everything sticky/yeasty.

 

[Poochops]

last night I put the starter in the fridge, it had had 48 hours in the airing cupboard where the temp is most stable and I shook it half a dozen times during fermentation, it was cloudy when it went in and had a nice layer of yeast on the base. So just now about 15 hours later I took it out, it was still cloudy but arguably less cloudy and with a bit more yeast on the bottom. I poured off 3/4 of the beer and warmed the remainder up to room temp, added another 2l of 1.040 wort and shook the bejeesus out of it several times, removing the lid in between shakes to gas off.
Basically I was wondering whether the beer should have been clearer or is it accepted that some cells will go down the drain, should I have done differently? And when it's finished should I let it clear fully before adding the yeast to the brew?
Thanks.

 

[Zephyr259]

I'm not sure as to what the "correct" answer is, but I leave mine in the fridge for 24 hrs if I can and most of the yeast drops out. From the starters I store it can take days or a week for some strains to drop completely clear so i think what you've done is fine. It's all a bit of educated guesswork anyway. :-)

 

[Poochops]

Yep! the more I read about it the more I'm realising that a bit of guesswork is needed
I'm in no rush anyhow now, I've got 2 cubes full of fresh wort from my Brewday today so when the yeast is finished working I'll crash it till I'm happy, probably a couple of days then pitch it in. Thanks for the tips :

 

[Zephyr259]

You're welcome, beer's pretty resilient. Temperature control probably has more effect than the assumptions we make in our "precisely calculated" starters.

Hope it comes out a good one.: