Chad Stevens Seibel Notes 2006:

 

• For the vast majority of brews, a minimum of 120 ppm of Ca2+ is desired in the brew water at mashin.  This helps maintain a more stable pH throughout the brewing process and in the final product.  Darker grains can handle even more Ca2+.
• Protein > Polypeptides > Peptides > Amino Acids > Moieties (combinations of stuff smaller than Amino Acids but bigger than a molecule) > Molecule > Atom
• Phytase – releases mineral content of the grain.
• Lager yeast can digest Rafinose, Ale yeast can’t.
• 1-4 linkages & 1-6 linkages:

 

 

 

 

 

• pH is critical in the solubility of alpha acids.  48 ppm soluble in 5.9pH wort; 400 ppm soluble in 5.2 pH wort.
• Keep mash pH between 5.4 & 5.6 for a whole host of reasons.
• Wort pH should be between 5.2 & 5.4 at end of boil.
• RIHE – Reduced Isomerized Hop Extract – is widely used for head retention.  Commercially available as “Tetra Hop” and “Hexa Hop.”  Use 2-3 ppm for foam stabilization, results in 1.7 times increase in perceived bitterness over traditionally brewed beer (Molson’s); post boil only, dosed at bottling; plain extract is best.
• Beta-Glucan is a polymer of glucose 1000 units long with alternating 1-4 & 1-3 bonds.  B-Glucan is exponentially more viscous below 153^of – keep above 153 during run-off.
• Ensure you do not go above 170^of during run-off or you will burst the starch in the “steely ends” releasing starch into the mash/wort and actually increasing the viscosity of the run-off.
• “Cinamar” is the German dark beer colorant used for most German dark & schwarzbiers.
• When yeast breaks down sugars, the result is 51% CO₂ and 49% alcohol by weight (with various other much smaller fractions, e.g. esters…).
• When checking for starch in an Iodine test, use as little iodine as possible – as little color as possible in the solution so you can see color change, not staining, in the starch molecules.
• In American (Molson’s) mash process, corn is boiled 20 min = 45 minutes from wetting to addition to the main mash.  Coors pressure-cooks adjunct to reduce time and pressure boils (“Mile High City”).
• Modern lautering holds clear wort as a high priority.  During the ‘60’s and 70’s, cloudy wort was considered no big deal; it just results in more trub, most brewers thought.  Studies have shown however that flavor suffers and colloidal stability decreases if cloudy wort is transferred to the boil.

 

• Charlie Papazian is the main arbiter of style in the world today.  The US is a big market and those who export to the US want our recognition.
• Clean your boiler once every 40 boils.
• 8% evaporation rate is THE standard “rolling” boil rate.
• Bigger floccs go into trub better – don’t boil so hard and long you break up the floccs.
• New Belgium is using a Merlin boiler.  They’ve had problems with it stripping desirable volatiles.

 

• Lessons from High Gravity commercial brewing:

 

1. Never ever ever add pure O₂ (nascent oxygen) to wort in ferment, and if you oxygenate with it, let the wort sit for a bit before pitching – results in cell wall damage & off flavors.  Use sterile atmospheric oxygen if you need to oxygenate wort in ferment.
2. Up to 20^oP (18^oP at Molson) up to eight generations before using new yeast culture.
3. Had to drop temp a bit and add zinc sulfate to control ester production.  Also added yeast hulls for nucleation sites.
4. Take temp down to where fermentation almost stops then bring back up a degree or two – to control ester production.

 

• High Falls & New Belgium add carbonated dilution water to their beer stream that has been pre-deoxygenated with a vacuum pump.  Beer stream runs about 8%+/-.
• Acetobacter – requires about 10,000 cells per ml to result in spoilage.  They increase 20 fold each fermentation; they don’t die out in ferment.
• Lactobacillus & Pediococcus – require 300-500 cells per ml for spoilage.
• Rule of thumb for new yeast propagation is 20-30 generations.
• Pitch 1 liter slurry per barrel of wort.
• Germans propagate at fermentation temp.
• In plant propagation – transfer to fermentor in log phase (at max yeast cell growth – high kreusen).
• Acid wash yeast with food grade phosphoric at between 2.1 & 2.2 pH, 2-4^oC, for no longer than 2 hours.  Don’t reuse yeast that was in beer of greater than 8% ethanol.
• Chlorine as an oxidizing sanitizer requires 200 ppm in solution.  Household bleach is a 3% chlorine solution.  You need to mix it 150 to 1 with water to achieve 200 ppm.  This is .53 cups bleach per 5 gallons water or 5.1 teaspoons per gallon.
• Iodophor – 25 ppm, weak tea.
• Big fermentors – chill wort stream to 65^of for a 68^of ferment so cooling jacket doesn’t draw yeast down to bottom of cone through advective currents.  And/or, let ferment take off before letting cooling jacket set point take over.
• Europeans ferment at 5 psi to decrease ethyl acetate and decrease fusel production.
• Laagering - beer max density is achieved at 37^of.  As temp falls below 37, a density inversion is created causing an upward flow from the bottom.  This inverse flow can have an effect on flocculation and haze settling.
• New Belgium Fat Tire fermentation – wort chilled to 15^oC (59^of ) then allowed to free rise to 26^oC (78.8^of) till finished out, then crashed to -1^oC for 48 hours before being filtered.
• Free-rise ferment – the cooler a liquid, the more oxygen it can entrain.  Additionally, the yeast use up all available oxygen within the first four hours of the ferment.  If you start out as cold as the yeast can operate, they will have much more O₂.  Ester production occurs at a background level throughout the entire length of the ferment, but the vast majority of esters are produced at the aerobic/anaerobic transition; you can see a huge spike in gas chromatography of headspace gases during this transition.  The higher the temp, the higher the ester production.  So, if you start out cool, and go through the a/ana transition cool, ester production will remain low even if you allow the temp to rise substantially later in the ferment.  Allowing the temp to free-rise results in substantially faster fermentations with lower final gravities.
• High Falls – any beer made with all malt 2-row gets zinc.  6-row wort has enough zinc according to the lab.  .2 ppm is the recommended amount of zinc in the wort at the beginning of fermentation.
• Pyruvate = pyruvic acid.

• Glucose

     6c (carbons)

      /\

3c       3c

               Glycerol    Pyruvate

                        |           |

                   Lipids    Ethanol (or may be changed into keto acids to provide amino acids)

 

• NAD is the coenzyme that drives this process – it’s how yeast get energy.  Nicotinamide Adenine Dinucleotide.
•       Yeast need O₂ in the wort to strip H from saturated fats to make UFA’s.
•       Yeast need .1% UFA in order survive.  Through natural budding, if the first generation has 1%, then subsequent generations have .5%, .25%, .125% and so on.
•        If pH is above 4.5, watch for diacetyl.
•       Alpha-acetolactate > diacetyl is a spontaneous reaction.  Oxidative decarboxylation of a-acetolactate – all it takes is a little O₂ at bottling, and a little heat, and you end up with diacetyl.  To make sure all the precursor has been metabolized, heat a sample to 140^of for 30 min, this forces the reaction, cool, taste side by side.  No diacetyl, no problem.  If there is diacetyl, do a diacetyl rest before bottling and check again.
•       Pump beer from as close to the tank as possible (as short a suction run as possible) and place the pump as low on the tank (below) if possible.  Don’t exceed 6-ft./sec flow rate.  Keep 17 ft. of head pressure or better to ensure CO2 remains absorbed.
•       Although hot fluids are less likely to absorb oxygen, polyphenolic compounds (anthocyanogens or tannin complexes) are readily oxidized.  Even though these compounds are removed in the trub, on the yeast, settled or filtered out, the oxidized flavors and aromas remain a part of the beer.  DON’T HOT SIDE AERATE.
•       Ball valves have wipers on either side of the ball.  When the ball is cocked partially open/closed, fluid can be trapped between the ball and the wipers.  This fluid is very difficult to get out and this area is very difficult to sanitize.  High heat may be the only way to kill everything in this type of valve.  Butterfly valves are much more sanitary.