Zymurgy

This will be a long boring post but useful to me. It's going to be a homebrewing "manual" of sorts, shamelessly copied from various sources, most expecially (so far) Charlie Papazian's Zymurgy teachings and John Palmer's How to Brew site and one more good one.  Also Adam's sort of led this charge with a recipe document (available only to those with whom the doc's been shared, though.)


So, here are some key topics:
  • Steep about 1lb/batch when making an extract beer..Steeped grains will add from 10-20 gravity points /(lb/gal) Don't get them over 170F or tannins will be extracted.
  • Mashed grains OTOH will reach about 0.03/lb/gal gravity change. Theoretical max around 38. So far I'm getting about 0.023 though. This "mash calcs" spreadsheet describes the temps and H2O quantities needed.
  • Sparging has the potential to generate tannins, especially as temp goes up and pH as well, as the diluted wort loses it's buffering ability. We have good water, so the buffering is far less of a concern here in Colorado. 
  • "Degrees Lintner" is the measure of diastatic power (enzymatic concentration). You need > 30L on average for the mash to complete in an hour. (This is the opposite of Lovibond which basically means darkness from roasting and you need 20 Lovibond or Less to mash.) Anyway, the "grain bill" listing type and quantity of grain to be mashed needs to average out to 30 Lintner, eg 2lb 120L "two row" and 6lb of carmelized specialty grain (denatured by the hot malting). 
  • The "Original (specific) Gravity" you ferment dare not be too high. The incremental specific gravity for added dry malt extract (DME) is about 0.041/(lb/gal) (about10% less for liquid malt extract) and one to 1.5 lb(DME)/gal is a pretty good quantity. OG above 1.06 is very high.   You can expect to yield 30"points"/lb in mashing, (including the sparge). That's dogma: I certainly haven't achieved it, got perhaps 20 points, on my 3rd try.
  • Palmer specifies "...standard mash conditions for most homebrewers: a mash ratio of about 1.5 quarts of water per pound grain, pH of 5.3, temperature of 150-155°F and a time of about one hour." there are multiple temps with different purposes, and higher temps destroy low temp enzymes, so you have to raise the temperature over time. Some good temps and their relevant enzyme are: protease at 130F,  then beta amylase at 145F, & alpha amylase at 157F. An insulated mash tun (drink cooler) will easily hold temp for 45 minutes with just a degree of drop. (Here're two a nice mashing summary videos  from BobbyNJ, who seems pretty expert, and here is linked John Palmer's  mash enzyme chart.
  • Sparge with another .5qt/lb to .75qt/lb, probably shooting for about 7gal of wort altogether. Doing this at 170F denatures all the enzymes & fixes the sugar mix. If you went hot (for alpha amylase) then it's important because otherwise the complex sugars will keep getting cut up until the boil starts. Since that's right away, this doesn't seem a big deal to me but maybe the time variability thus introduced is the problem. Doesn't seem like there's a big difference between English (batch) or German (continuous) sparging. German reputed to have higher yields, which matters 'cause it reduces the boil volume... Avoiding temp above 170 requires some attention. Calculate the quarts of H2O to reach 170F and thereafter dilute the sparge water down to 170F.
  • A starting gravity measurement is good now. Shoot for 7 gal to boil down to 5, thus the gravity is only 5/7 (71%) what it will be after the boil. Elevated temperature also makes the wort seem weak: at 90F, the hydrometer will read 0.0042 light, 006(100F), 008(110F),  01(120F) and 0.02 light at 160F. Tabulated.  This measurement could motivate some LME addition if deemed necessary (eg if something went wrong with the mash.)
  • Boil for an hour to extract hops bitterness. Hops in after the break. No lid: want aromatics to escape. Insulate the pot somehow? (A little Al foil works.)  I'm thinking of straining the break out (not tasty) right before adding hops, and straining the hops out right before the fermenter (plugs the kettle filter).
  • CP recommends boiling all the water because chlorine will mess with the beer.  Using pre-boiled and cooled water to speed wort chilling is a good idea though. This is for extract beers that can be boiled in concentrated form. Grain beers though, have to be boiled down to desired gravity, so dilution cooling's not possible.
  • Oxygen contact with the fermentation will create vinegar or solvent tastes, so prevent that. (dry ice chips in the bottom of the secondary?) Oxygenate before pitching, only! (...but do it very thoroughly then.)
  • you can't pitch the yeast until the wort is truly cooled: I've killed the yeast in the past.
  • Hydrate first, & then grow the yeast in a dilute solution: too much sugar can make it hard for yeast to hydrate and get started.
  • Add airlock and darkness, and wait.
  • Pitch aroma hops after the blow off, or in the secondary. Here again prevent O2 contact, filling the secondary with sterile water, perhaps? ...using CO2.

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