Saturday, July 5, 2008

A Lapsed Catholic

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.


Whorst said...

I use US-05 for my West Coast Pales, etc. For British beers I uses White Labs WLP005. I can't stand S-04. Maybe I need to try it again. It seems to mask all hop flavor and aroma. Thoughts?

Kieran Haslett-Moore said...

Yeah that has been mentioned to me before and I suspect there might be something in it. I have brewed well hopped beers with S-04 before however. I have a particularly hoppy batch of my Ordinary fermenting right now so that will be a test.

I think my experience with US-05 has been particularly coloured from my fermentation set up.

Anonymous said...

i wonder if trying out one of the lallemand yeasts is an option in the future if s-04 begins to annoy you. obviously nottingham is supposed to be clean, and possibly an ancestor of saf05, while windsor is a different beast again. but, as you have said before that your brewery tends to the malty anyway, an unattenuative yeast like windsor might leave things a bit unbalanced in the malt dept. worth thinking about i guess.