tag:blogger.com,1999:blog-2743871471433418538.post-86617350669675137342008-07-05T16:14:00.001-07:002008-07-05T16:15:35.458-07:00<a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://bp3.blogger.com/_FyzpRED8xTU/SHAAbZjsrEI/AAAAAAAAAjs/PJvJXjYsa7M/s1600-h/s-04.JPG"><img style="margin: 0pt 0pt 10px 10px; float: right; cursor: pointer;" src="http://bp3.blogger.com/_FyzpRED8xTU/SHAAbZjsrEI/AAAAAAAAAjs/PJvJXjYsa7M/s200/s-04.JPG" alt="" id="BLOGGER_PHOTO_ID_5219672438839487554" border="0" /></a>For sometime now I have been using Saf US-05 after becoming dissatisfied with my old yeast of choice Saf S-04. In the same period I swapped from fermenting in plastic jerry cans to fermenting in stainless corny kegs, as any brewer knows changing two variables at once is never a good idea but what’s done has been brewed. Recently I have been most concerned with the high ester character that my beer has shown. US-05 is renowned for being reasonably clean and neutral although there were murmurs from certain quarters about it having a potential acetal aldehyde problem. Certainly when used in my system with narrow tall fermentors with limited surface area the ester character has been significant and green apple has been a problem. And so I decided to dabble with S-04 again, many of the brews I did for the Winter Ales Fest were double batches with ½ fermented with US-05 and ½ fermented with S-04, S04 has won hands down. While the S-04 displays a little diacetyl post primary fermentation and if the fermentation gets to warm a little iso-amyl acetate (banana ester) the over all character of the beers fermented with S-04 is much cleaner. Like any Catholic its time for me to lapse I’m back in the S-04 camp.Kieran Haslett-Moorehttp://www.blogger.com/profile/04562970144894398803noreply@blogger.com