Wednesday, August 13, 2008

Diacetyl rest started for Oktoberfest; starters started for Altbier

So I had two beer-related things on my to-do list this evening. The first was make a starter for this Saturday, when I am planning on brewing my Altbier. The second is check the gravity on the Oktoberfest, which has been in the primary for eleven days and I'm ramping up for the diacetyl rest.

The starters were pretty routine. I'm making two 500mL starters for ten gallons of Altbier. Why two starters? Well, I'm pitching five gallons with White Labs WLP029 German Ale/Kölsch yeast, which I like (I actually just had an excellent Altbier that Iain at Rock Bottom Orland Park brewed with WLP029), but it bothers me that it came from a Cologne brewery. For the other five gallons I'm pitching White Labs WLP320 American Hefeweizen yeast. Why an American Hefe yeast? Well, the rumor is that this yeast came from Uerige, the most famous Altbier brewery in Düsseldorf, by way of Widmer. The problem is the yeast doesn't flocculate well, so you need to either treat it or filter it. As such, I bought some finings to add to the secondary. Anyway, stay tuned to find out how this experiment turns out.

In the meantime, determining what to do with the Oktoberfest gave me pause. I've always waited until fermentation was pretty much done to start my diacetyl rest, but in this case it's clearly still going. There's still a nice Kräusen on the beer, and it's gravity is reading 1034. With an O.G. of 1061 and an estimated F.G. of 1018, that means I'm only 60% complete with my fermentation, and I didn't want to start my diacetyl rest until I'm at least to 67%, if not 75%. However, Richard Stueven of the Green Bay Rackers recommends starting your diacetyl rest when you get around halfway done with fermentation. And the thing is, I have one temperature-controlled chest freezer and one lagering refrigerator which doesn't have a thermostat (it's just set to the coldest setting). Right now my chest freezer is full with ten gallons of my Oktoberfest, so I can't brew the Altbier until I can keg the Oktoberfest and get it out of the chest freezer. I tasted the beer and it definitely needs some time, as it still has some harsh edges (some phenolics and possibly some DMS or diacetyl) and I don't want to rush things. But I've decided to trust my brewer to the North (hey, if Wisconsinites don't know about lagers, who does?) and have ramped up the temp to 60°F from 50°F over the past two days. We'll see what happens. I'm a little nervous but it makes sense that you want to start the rest when fermentation is still active, as that's what cleans up the diacetyl. I guess time will tell if I made the right call.

So now the only question left is whether to brew Saturday or Sunday. I suppose I'll take a gravity reading on Friday and go from there. Look for an update then. For now, time to go to bed. Guten Nacht!


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