George Fix Decoction Conversation

At the risk of starting more debate (which is not a bad thing) I am passing along another link to another George Fix piece. This is an on-line conversation in which he talks a great deal about decoction. FYI

http://www.cmg.net/belgium/clubhub/transcript.html

It is interesting. I recently did a single decoction on a Weizenbock, and I'm really considering brewing it again using infusions in order to facilitate a direct comparison. I've mentioned melanoidin malt in other threads, as well, which I have used but have never compared directly to a decocted beer. I do wonder if it is just as effective as a decoction at introducing melanoidins into the finished product.

Thanks again BrewPastor for digging out such a great source of information. I see a lot of my views and techniques justified in this article:

G.Fix said:

Esters can be produced in many many ways. One of the most important is uncontrolled yeast growth at the beginning of the fermentation. As a consequence, I usually pitch at a few degrees lower than the steady state fermentation temperature because I have found the bad ester / nail polish tones can be very quickly formed from elevated temperatures at the very start. Ironically, we have also seen extremely high O2 levels (typically, when excess oxgenation of the yeast as opposed to the wort has been used). We are all concerned about lag times and correctly so. But, as far as esters go, I would prefer a "soft" start. more Where the fermentation may take up to 8 hours to get going, because of the initially low temperature. end

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This will make me work even harder to get the pitching temp for Lagers below 50F. The last one was pitched at 60F, which I thought was OK, but the fermentation started to fast.

G.Fix said:

In the temperature range of 140 - 145 F, beta-amylase is active. I find in my own brews that I can strongly affect the actual fermentability of wort by a rest in this range. The rest at 68 - 72 degrees C, pardon my change in temp's units does a number of things. Theoretically, this is where alpha-amylase is most active. There is also some new results showing that a rest in this range will incourage the formation of foam positive glyco-proteins.

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This shows Dr. Fix's german school of mashing. The 2 step saccrification (1405 and 168) will work very well for high to medium bodied beers. If you want to have a drier beer, you may have to do the Maltose rest at 150 in oder to get both amylases to work and convert most of the dextrines to fermentable sugars.

But I like the added benefit of the 2nd Sccrification (160F) rest -> improoved head retention (especially after I killed the head retention with my protein rest )

Kai

Kaiser said:

This will make me work even harder to get the pitching temp for Lagers below 50F. The last one was pitched at 60F, which I thought was OK, but the fermentation started to fast.

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I thought most people started their lagers ~65-70F and then chilled them once fermentation started?

<---- has never brewed a lager.

Teddy Roosevelt never brewed a lager? Wow!

Brewpastor said:

Teddy Roosevelt never brewed a lager? Wow!

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He sure as hell drank a few! Bully!

Baron von BeeGee said:

I thought most people started their lagers ~65-70F and then chilled them once fermentation started?

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That's the problem.

Home brewing literature commonly suggests that lagers are pitched warm and then cooled once fermentation started. But this is because home brewers notoriously underpitch their lagers. If they were not started a higher temps, you would not have enough yeast and a very sluggish fermentation. The latter seems worse than a the esters that are produced during the initial growth phase. Especially since most of these esters can be reduced by a diacetyl rest and/or long lagering. This is what I experienced with my first lager: strong alcohol aroma after 3 weeks, alcohol aroma was gone after 5 more weeks.

But in order to pitch cold, you need to have lot's of yeast (Noonan recommends 80ml of yeast sediment for a 20L (5Ga) batch. You won't get this much yeast when you make a simple 1-2qt starter. You will need to grow the yeast by making one starter, letting it ferment out, decanting the liquid, adding fresh wort, letting in ferment out ... and so on. This is best done on a stir plate in order to ensure good aeration. Which I still have to build for myself

Or you just reuse yeast sediment from the primary.

Kai

Baron von BeeGee said:

I thought most people started their lagers ~65-70F and then chilled them once fermentation started?

<---- has never brewed a lager.

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Not me. I pitch to fermentation temperture wort with a gallon of active yeast starter. My lag temps are 6 to 8 hours.

boo boo said:

Not me. I pitch to fermentation temperture wort with a gallon of active yeast starter. My lag temps are 6 to 8 hours.

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Boo Boo, when you pitch that large of a starter, aren't you worried about throwing off yout recipe. You should end up with 20% less IBUs if you pitch a gal of unhopped starter into a 5gal batch.

Kai

Kaiser said:

Boo Boo, when you pitch that large of a starter, aren't you worried about throwing off yout recipe. You should end up with 20% less IBUs if you pitch a gal of unhopped starter into a 5gal batch.

Kai

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I think pitching onto the yeast cake looks like the clear winner here. Well, once you get past that first batch!

Baron von BeeGee said:

I think pitching onto the yeast cake looks like the clear winner here. Well, once you get past that first batch!

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This means brewing a lager every other week. I don't think SWMBO will like this .

For the Oktoberfest, I used about 5oz of yeast from the Maibock primary. I revitalized it in a 2qt well oxygtenated starter which it completely fermented out within 2 days (at 60F). But I'm not really happy with the vigor of the fermentation. I have seen better and I thought I had enough yeast. But this beer has a long time go become really great; all the way to the end of September .

Kai

We need to have a good yeast thread again, along the lines of "how many generations..." Maybe I will work on that tomorrow.

Kaiser said:

But I like the added benefit of the 2nd Sccrification (160F) rest -> improoved head retention (especially after I killed the head retention with my protein rest )

Kai

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Again, something I can do with little effort and little cost. Add a half ppound of wheat to my grain bill for head retention. That just cut out an extra 30 minutes on my brew day.

So far decoction and stepping isn't adding one benefit that I can't do another way.

I'll put this out there again too--those of you who are doing step mashes (in cooler mashing systems) send me a beer and prove me wrong.

Brewpastor said:

We need to have a good yeast thread again, along the lines of "how many generations..." Maybe I will work on that tomorrow.

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I read something interesting I wasn't aware of in Warner's German Wheat Beers book. Apparently in an open fermentation where the yeast is cropped from the kraeusen it is possible to reuse it hundreds of time without fear of mutation, and they do. In a closed fermentation he indicates closer to 10 generations which is the number I was familiar with.