I agree with your numbers study and have read the results elsewhere previously when doing my own yeast testing. Despite the numbers; when comparing the resultant beer from dry pitching and rehydrating, I have found the rehydrated yeast to produce better beer. I have also found that pitching more yeast also produces a better beer. I don't how this all correlates, but it certainly seems to me that there is much more at play then just simply the number of viable cells. How they grow, multiply and work is obviously affected by the way they are treated.
little john's brewing ohh a world of possibilities is awaiting you my friend. Fermentation science and yeast health are two of my favorite things in brewing. There's so much to know and every little detail makes an impact in the quality of the beer, rate of fermentation, yeast health, cell density, growth rates, beer stability, and so on. I don't say that I have found any studies on beer quality with hydrated vs non-hydrated, however you are absolutely on target about pitch rates. I can't say there's a single most critical step, but this one is up there. The number of cells pitched certainly has an impact on flavor. A larger pitch will generally create a cleaner beer, faster fermentation, and clean up off flavors faster like diacetyl. However, this leaves the cells with less nutrients impacting cell health at the end of fermentation. If repitching continuously with a very high rate not only will you be able to use the yeast less, but it will have negative impacts on flavor as your population will be mostly old cells. The larger the pitch, the less growth. Being able to hit the sweet spot pitch rate for each strain is both art and science. This is generally accepted in the range of 0.75 to 1 million cells per ml of yeast per degree Plato for ales. As mentioned before, this is only one piece of the puzzle. Oxygen, sugar composition of the wort, wort nutrients, pitching temp, fermentation temp, free rise temp, the quality of flocculation, how quickly you harvest (and at what temperature), if there's any oxygen involved post fermentation, and of course how well you cleaned and sanitized your vessel all play major roles in the road to great beer and healthy happy yeast. I'm so lucky, at the brewery I work, to play a role in managing some of these things and it fills my heart with joy every day.
It is indeed an intriguing art. As you say, it is hard to find studies or tests on beer quality; the end result we are all after. I am doing testing and trial batches that compare simple things we as brewers do, and how they affect the beer we drink. I aim mostly at newer brewers to help with improving their results. In this case I was not worried about how the yeast would be down the track, most brewers are not reusing yeast so was based on clean fresh pitching. I was interested in your result of close to 200b cells in a dry pack, have never found any evidence to support that sort of number before. Cheers mate.
I make wine and I've pitched BREAD YEAST dry into wort and the eventual alcohol content was still in the range of what is classified as a wine. So no, hydrating yeast isn't necessary, especially if you're using a true brewing yeast.
Have to admit, I freaked out when I realized that I dry-pitched my very first batch of mead (simply forgot to hydrate). Thank you for this video and a super cool scientific study. I will be linking and sharing this video. Peace!
200 billion yeast cells per dry yeast package appears to be a common misconception. I can't find any references to a study to support that. The only study I could find found 8B cells/gram in Safale S-04, which equates to 92 B cells in the package. I think it's prudent to only expect about 100B cells/ package. Luckily dry yeast is cheap, so I always pitch double. See Van Den Berg, S., & Van Landschoot, A. (2003). Practical use of dried yeasts in the brewing industry. CEREVISIA, 28(3), 25-30 (Table 1).
This is really interesting information. Have you ever downloaded the Scott Labs Fermentation Handbook? Perhaps you can exchange some data with them, and maybe they can remunerate you in exchange.
Great video! Not sure if you're still responding to comments on this video but I noticed in the beginning there looked to be a bunch of M47 yeast packs. Have you used this before in a dubbel? I'm putting together a recipe to brew a dubbel and considering using that yeast but haven't found much information on it specifically in a dubbel.
I dig the work. I've been working to a low-energy sort of home brewing, so I've been pitching dry yeast for a while. Since I'm not propagating or harvesting, I've had exactly zero issues with it. Perhaps as I expand (hopefully soon) into to a more sustainable model I'll be able to validate what you've posted in a more scientific fashion. At this point, my conjecture agrees with your results.
Great video for us yeast geeks! I typically rehydrate dry yeast only to do 2 or 3 step starters. Yes I could buy more dry packs but DME in bulk is less expensive.
i guess im randomly asking but does any of you know of a tool to log back into an Instagram account? I was stupid forgot the account password. I appreciate any tips you can offer me.
@Chad Landen Thanks for your reply. I got to the site thru google and im trying it out atm. Looks like it's gonna take a while so I will get back to you later with my results.
Nico Tumulty Great question! Fermentis recommends 25-29C water temperature. I go right in the middle. Additionally, you want a 1/10 ratio of water to yeast by weight. So 11.5 grams to 115ml. Wort temperature for pitching depends on the style your going for. Generally clean, low ester, Ales you are looking to ferment at 20c. However, for optimal yeast health it's best to pitch 1-2C cooler and let the yeast bring the temperature up. The benefit of this is controlled yeast growth resulting in better yeast health, less leakage though the cell membrane, and a cleaner beer. This ties directly into having proper pitch rates though. Making great beer isn't one thing I another, but a series of small things in perfect harmony. Regarding hydration: I hadn't checked the Fermentis website in a while, but now in their FAQ they even state that you'll only see a 3-6% loss by directly pitching into wort without hydration. Fitting my numbers almost exactly. A lot can go wrong with hydration. Did the water get sterilized, was it too hot or cold, was the water ratio correct for best yeast health, did you give it enough time, etc. These can all result in damaging the yeast or infecting your batch if grossly mishandled. Thus direct pitching is a much safer bet.
