Decoction Reasoning & Why single infusion Just doesn't work

[Brandon]

[Brandon]

[lhommedieu]

Hey Guys,

I just joined the forum. It's nice to see a thread devoted to decoction mashing. I've been brewing for about 3 years and recently switched to decoction mashing German lagers. I agree that it's a labor-intensive method but it works for me. I've received a lot of advice from VladOfTrub over at HomeBrewTalk.com and use his Tri-Decoction method. I'm waiting for the weather to cool (I'm brewing in my garage and use the ambient temperature in there to cool and a Ranco controller + fermwrap to heat) as well as a 14.5 gallon conical to arrive before brewing my next beer, a Maibock.

Re. Victory pils: I think that it's a well-made beer that's drastically over-hopped (probably due to recent trends in American craft beer consumption that favor hoppy IPA's); I don't like it for that reason.

[Bryan R]

I am actually a step masher that is a converted decoctor now. I just can't get enough of it. WEe keep trying to get Mike( Vlad) over here....

[Brandon]

[lhommedieu]

I've used a chest freezer in the past to regulate my fermentation temperature, but I got worried about burning out the compressor, so now I just wait until the ambient temperature in the garage stays below 50F and use a fermwrap to bump the temperature up to where I need it. I wanted to follow a traditional German schedule and start brewing earlier this year, but the weather has not cooperated; hopefully my brewing season will run at least 3-4 months and I'll be able to brew enough batches to last the year.

[Brandon]

[lhommedieu]

I'm in Long Island, NY. I'm in PA quite often, as I have family in Williamsport. 70F is terribly hot for Christmas; I'm going to get my equipment out and set it all up over my Christmas holiday. Hopefully temps will fall in January and I can brew through March/April.

[Owenbräu]

Hitting the maltose rest after the first decoction (60-63C) is supposed to increase extract and fermentability as the boiling process has completely solubilized and broken down a lot of starches, which are then more readily available for beta amylase to chew down into maltose. I am curious, does the decoction also affect the structure of the starch? Can it break down the branches in amylopectin, thereby making more straight chains of starch available to beta amylase? Or, does boiling just release starches from the protein matrix and not affect the starch structure? Maybe I should start a new thread so not to hijack this one.

[lhommedieu]

Three quotes from VladOfTrub over at Homebrewtalk.com:

There are four enzymes that work on starch conversion. The a & b amylase, maltase and dextrinase. The enzymes don't necessarily make long or short chain sugar. What alpha enzyme does is liquify the starch into carbohydrates and amylose by taking the long chain starch and breaking it apart. The long chain has a reducing end and a non reducing end. Beta amalase can only break down the non reducing ends of the chain. Beta is responsible for forming fermentable maltose. What causes the non fermentability of wort is limit dextrins. The limit dextrins are at the branch "Y" after the amylose is broken down to amylopectin. They are a-limit dextrines. There are b-limit dextrins, too. Alpha enzyme produces maltriose. It is needed in lagers to allow for a long cold aging process. It also, produces some glucose which ferments and the a-limit dextrins that are non fermentatable....

Beta is active at 133F, working on amylose and amylopectin very slowly, when the pH is in the right band. A 10 minute rest at 133F, action of any kind is very limited, being close to useless.

Conversion can begin at 130F, even though the mash isn't at the temp for gelatinizing starch. Beta is active breaking up dextrin at low temps. In certain types of malt, Maltase and Dextrinase are not completely kilned off. They are debranching enzymes that make beta and alpha work better. Alpha, basically liquifies starch and breaks up amylose and amylopectin, forming carbs. It releases certain sugars, and a thing called a-limit dextrins. Beta only works on the non reducing end of the stewed up starch chain, creating sugar and b-limit dextrines. Alpha chops up the chain at certain points, creating more non reducing ends. Debranching enzymes create more non reducing ends. The more non reducing ends, the faster beta works.