When a diacetyl rest is used beer is krausened because when the temperature is cranked up Lager yeast go crazy and burn out. To complete the aging cycle and bring the beer back in line for natural carbonation to occur krausen is added. The rest is a blow out patch, diacetyl returns. Diacetyl is caused by a poor brewing process (chemically imbalanced wort lacking nutrients) along with poor quality yeast. It's better to repair the deficiencies than to use a diacetyl rest. The recipes and info about Lager and Pils cause problems which in turn causes a brewer to chase rabbits down holes trying everything to repair problems that may have been self inflicted.
Crisp and body are a balancing act involving saccharification, dextrinization and conversion and depending on the brewing method Mother Nature may be in control, not the brewer, and when Mother Nature is in control, we take what we get. Also, sweet tasting, non-fermenting types of sugar released by Alpha from the reducing end chain during saccharification are considered body in home made beer and that high temperature mashing creates big beer, which are not true. Limit dextrin is responsible for body and mouthfeel and dextrinization starts to take off at 149F and continues until Alpha denatures.
Depending on saccharification temperature the beer may turn out on the sweet side. You won't be able to tell at seven days. I'd say if it tastes sweet and gravity is 1018 transfer it and hope that the ducks line up. After two weeks in secondary (no diacetyl rest) place the beer in a keg without adding sugar. Make sure the gasket seals because sometimes they leak, and hope for the best. I have a feeling that natural carbonation will happen. Just hope that the beer is stabile enough to make it through the aging cycle without falling apart.
Oktoberfest is aged about nine months before it is tapped. At 1054, five, six months aging will work if the beer is intended to be naturally carbonated. Start testing for carbonation at two months.
If priming sugar was added and just by chance conversion occurred, the beer will over carbonate during the aging phase. The same thing will happen when CO2 is injected into the beer for carbonation instead of sugar.
To make Lager and Ale a few temperatures are required, along with boiling the mash, and using malt similar to Weyermann light and dark Pils floor malt. The malt is low in protein and slightly under modified. Throw in some sauer malz, too.
If a Beta rest wasn't used when the beer was made, second fermentation is kinda useless and it only increases the risk of infection and oxidation to set in. Beta is responsible for conversion. Alpha is responsible for liquefaction, saccharification and dextrinization.
During a Beta rest, 140, 145F, Beta converts glucose, which is simple sugar, into complex types of sugar, maltose and maltotriose. During the Beta rest Alpha is actively releasing glucose which in turn Beta turns into the types of sugar that make Ale and Lager. Pretty simple, right? Well, not really, because the quality of the malt used to make the beer comes into question. Depending on the level of modification it is very possible that the malt may not contain Beta or the enzyme is very weak and conversion will not fully occur during the rest, but not to worry, Alpha is busy pumping out glucose which yeast really loves a lot. The beer will end up very thin in any case.
An Alpha/Beta enzyme and several more types of enzymes are produced to make up for enzyme deficiency. The spec sheet that comes with each sack of grain is used to determine the quality of malt and to determine if enzymes will need to be added to make Ale and Lager with the malt or if the malt is more suitable for distillation. Data such as extract efficiency, gravity, pH, color, percentage of protein and level of modification are a few numbers that are listed on the sheet.
To counteract thinning and dryness caused by the Beta rest a type of starch is used. The starch is amylo-pectin, it makes up the tips of the kernel. The rest of the starch is amylose. Amylo-pectin is very hard, heat resistant, complex starch. Amylose is simple starch and it's not heat resistant. Amylo-pectin is the richest starch in the kernel and due to the heat resistance factor it does not "melt" at a fast pace until the temperature reaches 169F. When the infusion method is used at no time during the method is the temperature high enough to cause enough starch to enter into solution before Alpha denatures. The starch is the small, white, particles noticeable in spent mash.
Amylo-pectin contains limit dextrin which are tasteless, non-fermenting, types of sugar responsible for body and mouthfeel. When amylo-pectin is in solution, Alpha liquefies the starch chain at 1-6 links, releasing A and B limit dextrin and at the same time Alpha is busy liquefying amylose at 1-4 links, pumping out glucose. In the decoction method mash is boiled a few times and each time it is boiled more and more starch enters into solution. When the boiling mash is added back into the main mash dextrinization occurs. The finest Pils and Ale are produced from dextrin rich wort.
So far we got through kinda what Alpha does with simple and complex starch and what Beta does with glucose.
Now, let's assume that a Beta rest was used and the malt was rich in Beta amylase and maltose and maltotriose were formed during the rest.
Remember when I mentioned that yeast loves glucose a lot? Well, it doesn't care for maltose and maltotriose, too much. So, now what happens during fermentation when wort contains complex sugar; during primary fermentation yeast rips through glucose which is simple sugar, cranking out alcohol and it doesn't do anything with maltose because it doesn't love it, yet. So, after primary fermentation ends the beer is racked off the trub goop because after a while yeast begins to love the crap and off flavors occur which we don't want because the beer is going to be aged for months. The beer is transferred free of goop and ready for second fermentation to begin. (By the way, to get rid of trub, skim off hot break as it forms and after it ceases to form or greatly decreases, add bittering hops. Less hops will be needed because the wort will be a little cleaner. Skim off second break as it forms. Actually, it's good to rapidly cool the wort and allow it to settle for a few hours and rack the wort off the trub before adding yeast.)
During second fermentation another conversion occurs. Although, yeast prefers simple sugar because it doesn't need to work hard to get at it, it has to work hard to get at maltose, a di-saccharide. During second fermentation yeast absorbs maltose through the cell wall and within yeast is an enzyme that converts maltose back into glucose. The sugar is expelled back through the cell wall and it becomes yeast fuel. Gravity reduces closer to expected FG. During the aging cycle the same thing happens to maltotriose and natural carbonation occurs and expected FG is hit.
