tag:blogger.com,1999:blog-2261525107149934458.post8862015710652476197..comments2023-08-17T06:55:36.859-04:00Comments on Woodland Brewing Research: Side by Side Starters 4 of 4Anonymoushttp://www.blogger.com/profile/18109943319735098753noreply@blogger.comBlogger13125tag:blogger.com,1999:blog-2261525107149934458.post-19879154165395910222013-03-05T04:17:00.473-05:002013-03-05T04:17:00.473-05:00That's okay.That's okay.Anonymoushttps://www.blogger.com/profile/18109943319735098753noreply@blogger.comtag:blogger.com,1999:blog-2261525107149934458.post-48903186548808205552013-03-05T04:16:19.477-05:002013-03-05T04:16:19.477-05:00Yes, that's what I would expect as well. Woul...Yes, that's what I would expect as well. Would a Zn plated screw (that I use for a stir bar) cause problems with yeast growth? Anonymoushttps://www.blogger.com/profile/18109943319735098753noreply@blogger.comtag:blogger.com,1999:blog-2261525107149934458.post-40531417537108350182013-03-04T12:56:45.402-05:002013-03-04T12:56:45.402-05:00Steve,
Are you growing the yeast on the stir plat...Steve,<br /><br />Are you growing the yeast on the stir plate in wort? When I propagate yeast on a stir plate I see MB based viability in the high 90's. <br /><br />KaiAnonymousnoreply@blogger.comtag:blogger.com,1999:blog-2261525107149934458.post-87213154649406659862013-03-04T12:04:01.701-05:002013-03-04T12:04:01.701-05:00Thanks Kai,
That's very interesting, and make...Thanks Kai,<br /><br />That's very interesting, and makes more sense as it follows the conventional brewing wisdom. Even though this was 42 different fermentations they were all inoculated with the same yeast. I would like to run this again with a different strain under similar conditions. The "active" yeast was started on a stir plate and I am suspecting there is something wrong with it. Although the growth is nearly two times what I would get in a manually agitated starter, everything I grow using the plate has a fairly low viability. <br /><br />SteveAnonymoushttps://www.blogger.com/profile/18109943319735098753noreply@blogger.comtag:blogger.com,1999:blog-2261525107149934458.post-82151015334934184442013-03-04T11:57:57.082-05:002013-03-04T11:57:57.082-05:00Thanks. Sorry for not directing the comment direct...Thanks. Sorry for not directing the comment directly to you. That was actually a repost from HBT. I seem to have trouble submitting comments from my iPad mini. tagzhttps://www.blogger.com/profile/16458556996997515544noreply@blogger.comtag:blogger.com,1999:blog-2261525107149934458.post-43967314236171294832013-03-04T10:52:41.165-05:002013-03-04T10:52:41.165-05:00Steve,
Nice experiment and thanks for sharing you...Steve,<br /><br />Nice experiment and thanks for sharing your data. <br /><br />But I'm actually seeing the opposite when it comes to fresh and aged yeast. Fresh yeast (a day or two old) growths more cells per gram of extract than older yeast (5 days to a week old). The difference is quite noticeable. None of this has been published yet since I want to run a few more experiments in order to test my theory on yeast reserves. But I seem to be coming to a different conclusion than you.<br /><br />All my experiments are done with stirred starters. Maybe that makes a difference.<br /><br />KaiAnonymousnoreply@blogger.comtag:blogger.com,1999:blog-2261525107149934458.post-62840518981368807882013-03-03T20:36:17.179-05:002013-03-03T20:36:17.179-05:00The yeast used in the test was in the refrigerator...The yeast used in the test was in the refrigerator for about a month, so I would think you would be okay pitching it cold.Anonymoushttps://www.blogger.com/profile/18109943319735098753noreply@blogger.comtag:blogger.com,1999:blog-2261525107149934458.post-15199732934273960702013-03-03T13:12:32.415-05:002013-03-03T13:12:32.415-05:00So Woodlands research is showing that viability do...So Woodlands research is showing that viability doesn't decrease very much over a months time at fridge temps. He also showed that stored yeast can out perform starter yeast on a small scale because the stored yeast has built up glycogen reserves. So, if I have a jar of yeast that has been sitting for about 4 weeks, would it be better to directly pitch at an assumed 1B cells per ml or do a small starter to activate the dormant yeast and then pitch.tagzhttps://www.blogger.com/profile/16458556996997515544noreply@blogger.comtag:blogger.com,1999:blog-2261525107149934458.post-9175299550767275302013-03-03T05:37:15.428-05:002013-03-03T05:37:15.428-05:00Thanks for your reply. Sure attenuation depends on...Thanks for your reply. Sure attenuation depends on the sugar composition. I was just pointing out that this aspect might be left aside in your experiment here since you used the same wort for every tube.<br />Cheers, SamAnonymousnoreply@blogger.comtag:blogger.com,1999:blog-2261525107149934458.post-59870212540361581282013-03-01T18:58:18.007-05:002013-03-01T18:58:18.007-05:00Thanks for the suggestion on the chart labels.
...Thanks for the suggestion on the chart labels. <br /><br />You are right that the percentage of each type of sugar are the same regardless of gravity, but there is more to attenuation than the types of sugar. In this case there was a pretty wide spread of attenuation. <br /><br />Yes, for an ale your pitch rate is correct. These were pitched to be more like a typical starter where the brewer is looking to double or triple the cell count. In a typical ale fermentation the cell count grows ten fold but takes about a week to get there.Anonymoushttps://www.blogger.com/profile/18109943319735098753noreply@blogger.comtag:blogger.com,1999:blog-2261525107149934458.post-64982405579918279502013-03-01T16:40:05.076-05:002013-03-01T16:40:05.076-05:00Steven, thank you for the axis labels and the figu...Steven, thank you for the axis labels and the figure descriptions. Really appreciated. And thank you for your experiment as well. I am really fascinated by the fact that the refrigerated yeasts seem to grow to a higher concentration than non-refrigerated ones. Very well done. I as well don't think there is a correlation between the attenuation and the original gravity. I can imagine the amount of un-fermentable sugars (in %) in all the different original gravities would stay the same. By increasing the original gravity, the percentage of un-fermentable sugars will still be the same. <br /><br />On the other hand, don't you overpitch dramatically in all your experiments? A standard pitching rate for 10 mL of 15°P would be (1E6 cells mL-1 °P-1 x 15°P x 10 mL = ) 150E6 cells, right? And you used 290E6 cells 10 mL-1 as the lowest cell concentration. Are there any reasons for overpitching?<br />Thanks again, cheers SamAnonymousnoreply@blogger.comtag:blogger.com,1999:blog-2261525107149934458.post-65282434938520988122013-03-01T15:24:12.263-05:002013-03-01T15:24:12.263-05:00That's a good question. From the daily data b...That's a good question. From the daily data both started at about the same pace, but the refriderated yeast just kept going. http://woodlandbrew.blogspot.com/2013/02/side-by-side-starters-part-1-of-4.htmlAnonymoushttps://www.blogger.com/profile/18109943319735098753noreply@blogger.comtag:blogger.com,1999:blog-2261525107149934458.post-68946546576605087322013-03-01T14:28:44.816-05:002013-03-01T14:28:44.816-05:00Thanks for the great work. I wonder if refrigerate...Thanks for the great work. I wonder if refrigerated yeast would still outperform yeast from a starter when pitched into partially fermented wort, such as when trying to re-start a stuck fermentation. Do you have any thoughts on this?Lee Morganhttps://www.blogger.com/profile/00698409525485698378noreply@blogger.com