Concerned about a fast ferment using Saflager W-34/70

[rolomo]

I'm experiencing a very fast fermentation using 34/70.

I brewed a lite pilsner, 6 gallons net; pitched 3 packs of the yeast (I didn't have time to make a starter), and set the beer temp to an initial temp of 58f. After 24 hours I dropped the temp to 57. The next day, seeing the fermentation take off, I dropped to 56, and then to 54 the next day.

There seems to have been zero effect on the rate of fermentation. Over the three days the beer made a be line from 1.037 straight to 1.010. at this rate I should hit my FG of 1.006 tomorrow. That's 4 total days. Doing this in the past, multiple times, the fermentation would take about 7 days. Only difference that I can see is the 3 packs of yeast versus 1 pack and a starter.

Should this be expected? Was my starting temp to high? Should I have ramped down faster?
For references, 40/70 temp range recommendation is 53.6-64.4°F, so 57f would be on the low side.

 

[FloppyKnockers]

I've never used 3 packs in the same batch. I know it says 11.5g for 10 - 15L, but I didn't see that when I first used it nor the subsequent 30 times thereafter. I've always only used one pack.

I also subscribe to go low on ales, high on lagers. Since ideal is 53 - 59 for this yeast, I aim for around 57. I've never had a problem with it not fermenting or off flavors.

I think the reason why yours took off so fast and finished so quick was the relative low gravity and arguably - a lot of yeast.

The plus side is that your can jar that yeast cake into thirds and make several more batches before having to buy more.

 

[SanPancho]

yeah, thats a **** ton of yeast considering your OG. i mean 1037 is basically starter wort. three packs is crazy overkill. even two would be overpitch at that OG. i'd wager thats gonna be a pretty clean pils

 

[pvtpublic]

yeah, thats a **** ton of yeast considering your OG. i mean 1037 is basically starter wort. three packs is crazy overkill. even two would be overpitch at that OG. i'd wager thats gonna be a pretty clean pils

1037 is a really low OG for 3 pkg of yeast. You only needed one. Also, that much activity at those higher temps may result in a less than clean lager. You might still be ok, but with that pitching rate, you might have stressed the yeast pretty good.

 

[SanPancho]

negative. the yeast have basically been short-cycled.

warmish temps. huge pitch count. means little to no ester formation. 34/70 is fine up into 60s no problem, so fusels or other crap isnt an issue either. most likely i'd wager (assuming all other aspects are normal) that there'll be so little esters as to seem watery.

 

[pvtpublic]

negative. the yeast have basically been short-cycled.

warmish temps. huge pitch count. means little to no ester formation. 34/70 is fine up into 60s no problem, so fusels or other crap isnt an issue either. most likely i'd wager (assuming all other aspects are normal) that there'll be so little esters as to seem watery.

Esters and fusels wouldn't be what I would expect, more like polyphenols/autolysis like off flavors. Perhaps some solvents, starved yeast characteristics. I wouldn't expect any off flavors to be prominent, if detectible. It might be really thin and flabby considering both the pitch rate and OG. Certainly won't have an issue with acetaldehyde or diacetyl, haha

It could still wind up being really enjoyable. I've messed up pretty good on some beers that shouldn't have wound up being any where near as good as they were.

 

[Red over White]

I'm experiencing a very fast fermentation using 34/70.

I brewed a lite pilsner, 6 gallons net; pitched 3 packs of the yeast (I didn't have time to make a starter), and set the beer temp to an initial temp of 58f. After 24 hours I dropped the temp to 57. The next day, seeing the fermentation take off, I dropped to 56, and then to 54 the next day.

There seems to have been zero effect on the rate of fermentation. Over the three days the beer made a be line from 1.037 straight to 1.010. at this rate I should hit my FG of 1.006 tomorrow. That's 4 total days. Doing this in the past, multiple times, the fermentation would take about 7 days. Only difference that I can see is the 3 packs of yeast versus 1 pack and a starter.

Should this be expected? Was my starting temp to high? Should I have ramped down faster?
For references, 40/70 temp range recommendation is 53.6-64.4°F, so 57f would be on the low side.

How does it taste? I would not sweat anything until I could taste the results.

 

[VikeMan]

Regarding pitch rate, severe overpitching can cause some issues. Among them are excessive Acetaldehyde and Fusel Alcohols, and (faster) Autolysis. But how much of an overpictch (if at all) was this?

A typical pitch rate for lagers (real life world class commercial breweries, not dumbed down package instructions (which are not true "rates" at all)) is 1.5 Million cells per milliliter per degree Plato. 6 gallons of wort is 22713 ml. OG of 1.038 is 9.5 degrees Plato.

So at a standard lager pitch rate, you would want:
1.5M cells/ml/P x 22713 ml x 9.5 P = 323.66B cells

For 34/70, Fermentis guarantees "Viable yeast > 6.0 x 10^9 cfu/g" (i.e. 69 Billion cells in an 11.5 gram pack)

69 B cells per pack x 3 packs = 207 Billion cells

So, at a standard lager pitch rate and at Fermentis' own guaranteed minimum viable cell count, 3 packs would actually be an underpitch vs the desired ~324B cells.

OTOH, you will find many who claim that there are something like 200B cells in an 11.5 gram dry yeast pack, because someone once counted them. All I can say to that is that if Fermentis was consistently delivering anything close to 200B cells, they certainly wouldn't promise only 69B.

But let's speculate that there are actually 200B cells per package. Why not? It's the internet, the land of wishful thinking. When you sprinkle dry yeast into wort, you might lose about 50% of the cells. How do we "know" this? Someone supposedly measured it, just like the 200B cell count. So now we're looking at 200B x 3 x 50% = 300B cells. Pretty close a standard lager pitch rate.

TLDR: Arguably, many homebrewers underpitch their lagers. Your pitch was probably fine.

 

[hotbeer]

I don't do lager's. But since I got a RaptPill, I've seen that all my beers reach FG in 3 to 4 days from pitch. However there is more that goes on after FG is reached that takes longer and is why many of us probably wait 2 to 3 weeks or more to bottle or keg.

I don't know why you are concerned. Do you know for a fact that all your previous brews took longer to reach FG? I seldom ever checked FG of my previous beers until after all the suspend stuff fell to the bottom leaving a clear beer. Sometimes that was almost 6 weeks.

 

[mac_1103]

Regarding pitch rate, severe overpitching can cause some issues. Among them are excessive Acetaldehyde and Fusel Alcohols, and (faster) Autolysis. But how much of an overpictch (if at all) was this?
...
TLDR: Arguably, many homebrewers underpitch their lagers. Your pitch was probably fine.

I did read it, and what I got from it is that unless you have a microscope you really have no idea what your pitch rate is. Maybe it's just me, but I think this is fairly important. I mean, we all know that actual measurements have margins of error, so why do we so often pretend that estimates we find on the internet don't?

 

[rolomo]

I don't do lager's. But since I got a RaptPill, I've seen that all my beers reach FG in 3 to 4 days from pitch. However there is more that goes on after FG is reached that takes longer and is why many of us probably wait 2 to 3 weeks or more to bottle or keg.

I don't know why you are concerned. Do you know for a fact that all your previous brews took longer to reach FG? I seldom ever checked FG of my previous beers until after all the suspend stuff fell to the bottom leaving a clear beer. Sometimes that was almost 6 weeks.

I

 

[belgabrewing]

Holy schnikes...With that much yeast I am surprised you could not hear it buzzing!

 

[rolomo]

Following up on this thread. No issues with the beer or the firmentation. Came out clean.

Thanks everyone for the constructive inputs. Btw, the yeast packets were 2-years old, so thats why I went with three and a starter.