Guest Posted August 8, 2011 Share Posted August 8, 2011 I have for a long time taken great pains to aerate (whisk the bejeezus out of it) my wort prior to pitching, however I rehydrate my yeast in cooled boiled water now and rerely, if ever... just 'sprinkle' here's the thing.. Dry jeast comes with not only all their starter nutrient but also an oxygenator.. ?? So IF I have this right and Im open to suggestion if you are out there PB, that you are better off rehydrating dry yeast into water first and then adding to the wort after 15-30 minutes or as I like to do slowly introduce wort to the rehysrated yeast and then pitch.. being that they can better control what goes in and out of the cell wall.. Ive often read about a 'kill rate' of up to 50% of viable cells if just sprinkled.. (possibly less?) whats the word on this? Do I have my understanding correct? If not where is it out? Now I know that alot of Manufacturers reccomend rehydration into water first Im wondering if it is for these reasons? Is it detrimental when pitching Dry yeast to have too high an 02 count? Yob Link to comment Share on other sites More sharing options...
weggl Posted August 8, 2011 Share Posted August 8, 2011 Bit too technical for me Yob, I aerate the wort simply by filling it with a hose on pretty hard, puts heaps of air in it. As for dry yeast I usually chuck a couple of teaspoons of Dex into some cooled boiled water, throw in the dry yeast and give it 1/2 hour on my stir plate. Its up and running when I\u2019m ready to pitch. I don\u2019t worry about all that other stuff. I do the same with cultured yeast, Dex and water. Its never failed me yet. Stay cool, don\u2019t worry. Warren Link to comment Share on other sites More sharing options...
Guest Posted August 9, 2011 Author Share Posted August 9, 2011 it's the technical stuff Im after, Not so important if you (as I do) re-use yeast. (as you have the required viable cell count already) But when I come to pitching a fresh packet I want to do so with methods that ensure maximun Yeast health. I find 50%-80% of the research I do is yeast related. A better understanding and practice of good yeast management can never hurt the end product. Very interested to see what PB2 Has to say on the topic when he gets a chance[joyful] Link to comment Share on other sites More sharing options...
weggl Posted August 9, 2011 Share Posted August 9, 2011 Yob, you must have a lot of patience, counting yeast cells![love] Link to comment Share on other sites More sharing options...
Guest Posted August 9, 2011 Author Share Posted August 9, 2011 love MR MALTY... Ive been making so much better beer with propper yeast management, but to be able to manage it propperly you have to understand it.. this is what I want to clarify here, that is.. something im not sure of.. starters no worries, cleaning and repitching viable yeast cells no worries, knowing what hop oils do to yeast cells got it.. when and why to ramp temps up yep no drama etc etc.. I could go on.. months of learnin and IMO time well spent. and I have MUCH more to learn yet like below. is pitching dry yeast into aerated wort bad for yeast? is it better to aerate after pitching the yeast? Water or wort? dunno for sure, jury is still out[bandit] These are all valid questions if you care for your yeast and also the end result. Yob I fully intend to email a few manufacturers that I use alot, coopers included, as can be seen here. Link to comment Share on other sites More sharing options...
Hoptimus Maximus Posted August 9, 2011 Share Posted August 9, 2011 is pitching dry yeast into aerated wort bad for yeast? is it better to aerate after pitching the yeast? Water or wort? I know Fermentis suggest if pitching the yeast without rehydrating then wait 30 minutes and then aerate. Guess that does not answer your question whether pitching into aerated wort is less desirable than pitching into non aerated wort. I suspect it is not harmful but rather the best result is to aerate after the yeast rehydrates itself slowly when sprinkled on the wort surface. Yes one can find so many questions. Sometimes I think we pamper these little suckers and that they are tougher than we give them credit for. Link to comment Share on other sites More sharing options...
Guest Posted August 10, 2011 Author Share Posted August 10, 2011 Sorry Yob, I can't answer your Q's and this is slightly OT but the Yeast book is a great read. I have it at home but will try look it up if I think of it later. Someone like Wolfy on AHB may have an idea. PS, I love your hop garden coming together. I've been watching with interest. Link to comment Share on other sites More sharing options...
PB2 Posted August 10, 2011 Share Posted August 10, 2011 Wort aeration is more relevant when pitching liquid yeast or yeast that has been through one or more full primary fermentation cycles. It's okay to pitch dry yeast onto an aerated wort or non-aerated wort. Most of us brewers, making 20 to 23 litre brews, are not likely to achieve a dissolve O2 rate anything more than 4ppm. Link to comment Share on other sites More sharing options...
Guest Posted August 10, 2011 Author Share Posted August 10, 2011 It's okay to pitch dry yeast onto an aerated wort or non-aerated wort. Most of us brewers, making 20 to 23 litre brews, are not likely to achieve a dissolve O2 rate anything more than 4ppm. thats sweet news indeed, the question now is I guess though, at what ppm does it become a concern for dry yeast? Not that I have the equipment to test for such things, just interesting to know these things... id love to see/play with some of the equipment you guys must have[love] Link to comment Share on other sites More sharing options...
LeonardC2 Posted August 11, 2011 Share Posted August 11, 2011 Well,I've done some experimenting myself in this area. I liked how My English bitter performed with the re-hydrated yeast. I put 2tsp of dextrose in 1.5C of luke warm water,stirred to dissolve. Then stirred in the cooper's 7g ale yeast sachet. I let it sit 2 hours,15 min while I tried to chill down the wort kettle on a hot day. It started bubbling some 9 hours after I pitched it. Rather quick,steady bubbling. It got down to 1.008 from 1.030. I made it from the package kit. Re-hydrating with dex seems to work well for pale to mid ales. But my small starter took my IPA (based on the OS draught can) with DME from 1.050 down to 1.010! So they can help cut lag time. They start more vigorously as well,ime. I noticed that the cooper's ale yeast is also available in a 15g sachet too. A quick re-hydrate with that one should handle a mid gravity ale quite easily. Link to comment Share on other sites More sharing options...
Guest Posted August 11, 2011 Author Share Posted August 11, 2011 more info in this link.(Brew Strong) Aeration going to listen to it again, im sure they said 8ppm was what the average homebrewer could achieve... [unsure] Link to comment Share on other sites More sharing options...
PB2 Posted August 11, 2011 Share Posted August 11, 2011 I caught up with our resident Dr. Yeast in the tea-room and quizzed him: Can a wort have too much saturated O2 at the start of fermentation and if so how much is too much? What effect would this have on the beer? Not verbatim but the gist of his answer went something like: Different strains have different O2 needs, 12-15ppm is common. O2 levels over 25ppm is considered too much for most yeast strains, producing odd flavours (which he did not elaborate on). The bonus when using dry yeast is that elevated O2 levels are not really necessary for a clean fermentation. Too much saturated O2 is not something to worry about for us amateur brewers - it's a bit like stressing over breaking the open road speed limit when you drive a clunker that can only do 80kph tops. [lol] Link to comment Share on other sites More sharing options...
Matty A Posted August 11, 2011 Share Posted August 11, 2011 it's a bit like stressing over breaking the open road speed limit when you drive a clunker that can only do 80kph tops. [lol] Can we go downhill to get it [biggrin] Link to comment Share on other sites More sharing options...
Guest Posted August 11, 2011 Author Share Posted August 11, 2011 Nice one PB, thanks for that, it's awesome to get a responce like this to a serial pest on a quest[lol] (for knowlege) Fom what I can gather, with "air" the most saturation you will achieve is about 8ppm, and for worts below 1050 this is fine. (and as you correctly say, different yeast have different needs) With O2 injection via stone etc, these levels can be raised but is linked to the pitching rate required for both the wort and the yeast selected... it's all quite complicated but as my worts are 'usually' never over about 1050(ish +/-) it's not going to be a real issue... This is not to say that I dont want to understand the science behind it and learn more. My thanks to you and the resident Good Dr Yeast[happy] Yob Link to comment Share on other sites More sharing options...
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