I have used SNS starters the last couple of years and my fermentations with them have been fast, furious and mostly krausen-free. These are the characteristics of an overpitch, and even when I have only pitched half the starter into a 5 gallon batch it still happens. When I use dry yeast or if I make a stir-plate (and chilled and decanted) starter I get normal krausen and a more restrained fermentation, so I know the problem is with the yeast.
Many of the new yeast packages don’t require a starter at all so I think I will start direct pitching if the package is new and only make a starter if the package date is nearing its “best by” date. When I need a starter I will continue to make 1 liter starters in a 1 gallon container with OG = 1.030 - 1.035 and just pitch smaller and smaller fractions of the starter until I find the amount that works properly.
Has anyone else faced this issue with SNS starters?
What is the fault in the beer that you are trying to correct? How are you defining “overpitch”? For me, unless there is an issue in the finished beer, I don’t really care much what fermentation looks like.
The only issues I’ve ever had from overpitching are restrained esters in English ales in general, and diacetyl in WLP002 specifically. These have all been related to using a full pack of yeast (suitable for 5 gallons of beer) and pitching it all into a small (2.5 gallon or less) batch size. I’ve never had an issue with my SNS starter beers, even when pitched in a 2.5 gallon batch.
You just nailed the fault. I have had “restrained esters in English ales” and some lack of character in other beers that have been outstanding in the past. I have also had head retention issues except with the hoppiest of beers made with SNS starters.
Perhaps I am misdiagnosing, but what else could cause this behavior? My fermentation temperatures are not too high - generally 67 or 68 F for ales. I have double and triple-checked my thermometer to make sure of that. I have “normal” fermentation with krausen if I use dry yeast or a stir plate starter, so I know that my overall process is fine.
I know I have mentioned this in the past and maybe one of our resident yeast gurus can put a finer point on it but… when the right amount of yeast is pitched and the yeast go through their various phases, the yeast produce more flavors that beer drinkers find “pleasing”. You just end up with a tastier beer. If you pitch more yeast than you need, the yeast may not behave the same way and may not produce these flavors. Of course you’ll still have beer but you may not find it as good. Many times when I harvest yeast I end up with about 400ml of slurry in a flask. Not all of that is yeast, clearly. I seem to remember the old Mr. Malty yeast calculator telling me I needed between 180ml and 200ml of lager yeast slurry for a 1.050 lager. Poke holes in that concept if you like… I have no idea if it still holds water. That said, I typically pitch about half of the harvested yeast into a new batch as opposed to pitching ALL of it and it comes down to the concept of the yeast going through its various phases. As far as diacetyl in English Ales… S-04 will do that to me if I don’t get the fermentation warm for a bit towards the end. Head formation and stability never suffered and esters seemed normal.
somewhat related to OP, who i think answered their own question(statement), but he is right about increased cell counts and the suggestion of -just dumping the yeast pack directly in, no starter- is actually pretty well true these days and an industry minimum standard.
white labs has redone their packaging so they have some larger pack whcih my online homebrew store has replaced the older small packs with.
Ales with a specific gravity < 1.064 (16 °P): pitch 1.0 Kg (2.2 lbs) of thick slurry (40% yeast solids) per 1 BBL (1.17 hL) or 1 Liter (1 quart) of thick slurry per 1 BBL (1.17 hL)
Lagers with a specific gravity < 1.064 (16 °P): pitch 2.0 Kg (4.4 lbs.) of thick slurry (40% yeast solids) per 1 BBL (1.17 hL) or 2 Liters (2 quarts) of thick slurry per 1 BBL (1.17 hL)
High lagers with a specific gravity > 1.064 (16 °P): pitch 3.0 Kg (6.6 lbs.) of thick slurry (40% yeast solids) per 1 BBL (1.17 hL) or 3 Liters (3 quarts) of thick slurry per 1 BBL (1.17 hL)
I believe 1 US BBL ≈ 31 US gal. 1 US Qt ≈ 32 US fl oz. So, ~ 1 fl oz per gal Ale harvested yeast slurry and ~ 2 fl oz per gal Lager harvested yeast slurry < 1.064. ~3 fl oz per gal harvested yeast slurry > 1.064 to meet the WYeast Professional recommendation.
I have had good results with this recommendation.
To meet this recommendation, Ken will need a little over 3 more oz of slurry in his lager in a 5 gal batch < 1.064. (200 ml ≈ 6.7 fl oz)
Not the exact answer you’re looking for, but for 3 gallon batches I would pitch 1 of the old PurePitch pouches no starter and get the performance I was looking for. I’m guessing that the new pouch sizes will be suitable for most 5-gallon batches, if for no other reason than to be competitive with Omega and Imperial’s larger liquid packs.
I always wondered why some of the yeast packages had language on them like “100 Billion Cells. Enough to pitch directly and successfully inoculate 5 gallons of wort”. That suggests you could smack a pack of Wyeast 2124, wait for it to swell and use it without making a starter… which I have never heard of anyone doing. I have done that with five gallons of 1.050 ale wort but not a lager. I have also seen brewers make something like a porter and pitch THREE pouches of 1056. Somewhere in there we got the message that you need to pitch massive amounts of yeast and we also got the message that there was such a thing as underpitching (this is very bad we were told) but not overpitching. Could you overpitch and create a beer that was not as good as pitching the proper amount of yeast? I think so.
Also: I once bought the 1056 equivalent of Imperial’s ale yeast. No nutrient pack to smack. The yeast was fresh so I brewed, used pure O2 in the wort and pitched. It took something like 36 hours to start and the beer was dreadful… ultra-cloudy and the flavor was really off. Part of that had to be on me but why did fresh ale yeast take so long to start? I should have made a starter, clearly.
For a small batch brewer that doesn’t “harvest” yeast, it is very discouraging. The last thing I want to get involved with is measuring yeast on brew day - especially liquid yeast - but maybe I should start, at least to confirm or deny the possibility. Open packs of dry yeast should be easy enough to store, but the remainder of liquid pouches would end up getting discarded.
Yeast always has a level of mystery to me. You can’t look at a container of yeast and understand it’s health status, how many viable cells there are, etc. Yet yeast has to be the most important part of the process so these two things cause me some anxiety sometimes. 99 times out of 100 it’s not an issue but I’m always thinking about it. It’s one reason why I have been embracing dry yeast more and more because it’s easier to control, easier to use, has a longer shelf-life and using the right amount seems easier. The truth is that I am a beer drinker who likes to make and drink beer. I am NOT a scientist so when our yeast experts share information I tend to listen. I have been using SNS starters now for my last three runs of lager yeast and my beers have been coming out great… not necessarily better than with my stirplate starters but still… the beer has been good.
I struggle with repitching rates when I make really low ABV beers (under 4% ABV). Back in the day the rule of thumb was a third of the slurry from a modest ABV ale into an equally low ABV ale; but a about a half of the slurry from a modest ABV lager into an equally low ABV lager. Then adjust upward for bigger ABV ales and lagers, to include the full slurry (from a modest ABV lager) into a high gravity lager, such as a dopplebock.
The recommendations from Keith seem to be in line (or perhaps just a bit higher slurry volume) than my old rules of thumb. If the slurry is harvested on the date to be re-pitched (very fresh), I now consider the re-pitch to take just a little less than the amounts we both indicated in order to see nice yeast growth, but with quick starts. Oxygenation is also helpful on re-pitches from the perspective of fermentation taking off quickly (and unnecessary in the context of dry yeast direct pitching).
I think it would be beneficial for homebrewers to worry less about cell countvand concentrate more on yeast health and vitality. That could reduce overpitching.
The new liquid yeast packages have higher cell counts, perhaps higher than necessary, when they are fresh from the factory. By the time a homebrewer gets around to pitching that yeast there will be fewer viable cells. Without the capacity to stain and count cells, there is really no way to tell the health and viability of a package of yeast. I purchase liquid yeast from a store that I know has a good distribution chain that keeps the yeast refrigerated at all times, so that helps. The most popular strains are purchased and re-stocked frequently, while less popular strains might sit around for months. I recently purchased 2 of the new White Labs pouches and one of them was packaged in January. If the pouch was only 2 months old I would just pitch it directly, but I decided that for a mid-June brew I needed to make a starter. Then I know that the revitalized yeast will be healthy, but I will pitch only part of the starter to make sure I am not overpitching.
My concern as a 3 gallon brewer is simply whether or not I should be pitching a full 11g pack of dry yeast or should I stick to the Mfg’s pitch rate calculator. Almost always I am overpitching, but does it affect the finished beer?
That was the question I sent to Lallemand earlier today. Hopefully I’ll get a reply.
based on using that lallemand calculator, for brews this year and retroactively checking beers that had imho yeast related issues. i think it is an accurate tool. simply having this tool, let alone having some imho better strains than fermentis has solidified lallemand as my go to dry yeast choice. i DID contact fermentis about if they were working on or had a yeast pitch calculator and they never replied to me.
also @megary, yeast "harvesting imho is incredibly simple. i usually do 2 or 3 beers off of a yeast i choose and simply take the yeast left on the bottom and put it in a 1 gallon glass carboy i habe, sanitized and then add that directly to the wort anywhere from that day up to 10 days later. it has never, ever been an issue.
Yeah, I have been harvesting yeast for as long as I’ve been brewing. I’m very careful with sanitation and I just pitched 2124 into a SEVENTH batch this spring! :o