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Messages - nyakavt

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All Grain Brewing / Re: Efficiency: How Good is Too Good
« on: January 20, 2012, 08:20:24 AM »
Batch sparging efficiency can be broken down into mash and lauter efficiency.  Mash efficiency is affected by crush, grist yield, mash pH, time, temp, etc.  Basically how much of the potential starch do you convert to sugar?  Lauter efficiency is a measure of how much of this converted sugar you get out of the mash tun.  This is affected batch-to-batch by how much water you mash/sparge with, and there are fixed losses associated with dead space and apparent grain absorbtion.

You can measure the mash efficiency by taking a gravity reading of the mash.  This can be compared with the theoretical yield of the malt, preferably from a lot analysis of the malt you are using, a general analysis posted on the maltsters website, or a more general assumption (e.g. 2-row yields 36 p*gal/lb).  This can be improved most easily by crushing finer, but ensuring all your mashing parameters are in the correct range (pH, temp, time) is important for consistency and getting max yield.

Lauter efficiency is correlated directly with how much water is used to mash.  If you have 10 lbs of grain and mash/sparge with 10 gallons of water, you'll have a higher efficiency than if you use the same amount of water with 15 lbs of grain.  This is because the wort/sugar that is held back in the mashtun (by grain, dead space) is not as dilute, so you are effectively leaving more sugar behind.  There's not much we can do to improve this, because we typically have a fixed boil volume and don't want to boil 15 gallons down to 5.  So usually this effect is just accounted for, you'll notice a decrease in efficiency with bigger beers.

Kai has several articles on batch sparging efficiency analysis if you want more info, or you can just ask if you have specific questions.

Kegging and Bottling / Re: Homebrewer innovation : Mass bottle sanitizer
« on: January 19, 2012, 08:11:14 AM »
Anybody have suggestions on this front?  Most of my bottles are pretty nasty and don't get rinsed right after emptying.

Suggestion #1 would be to do something about the above

Yeah, that doesn't do much for the 500 or so that are sitting in the attic and have already been abused  ;D  Most of these were dirtied back before I started kegging and at a tailgate, so no running water.  I'd be lucky to just get most of the empties back.  They probably would have been fine if cleaned the next day, but hey if I wasn't lazy we wouldn't be having this conversation  ;)  Now they have a nice dried on layer of sludge on the bottom.  I wonder if it's less effort to remove labels from new bottles or clean the old de-labeled ones?

Kegging and Bottling / Re: Homebrewer innovation : Mass bottle sanitizer
« on: January 18, 2012, 07:06:40 AM »
These are conceptually like little landscape irrigation systems.  Similarly, all you need to do is design the laterals in a looped configuration as opposed to having several distal ends that will always have emitters with less pressure than those closer to the source.  Simply connect the end pieces with tees and a couple 90 degree elbows to create a continuous loop around the emitters. The pressure will equalize and it will perform much more as you intended. 
That said, man that's a lot of work compared to a dishwasher or starsan/bottle tree. But hey, sometimes it's about the process,  right?  ;) 

Now that you put it that way, it makes perfect sense.  I never thought about closing the loops.  Thanks, that helps a lot.

For sanitizing, yeah this seems like a waste of time, especially compared with just using a hand sprayer and hanging on a bottle tree.  But for cleaning, it would be great to have something so I didn't have to break out the bottle brush.  During the last mass cleaning I had to use the brush on about 40% of the bottles to get them sparkling, even after an oxyclean soak.  Anybody have suggestions on this front?  Most of my bottles are pretty nasty and don't get rinsed right after emptying.

Kegging and Bottling / Re: Homebrewer innovation : Mass bottle sanitizer
« on: January 17, 2012, 12:43:42 PM »
That's funny, I built almost the same thing about a year ago out of 1/2" CPVC.  The guy is right, the CPVC end caps caps are bigger than the bottle opening.  I got some 1/2" solid PVC stock from grainger, cut it into 1/2" long rods, and hammered it in the end of the CPVC.  Then a hole was drilled through the solid stock. 

Unfortunately I couldn't get mine to work properly.  All the flow was at the first few pipes next to the supply, the rest were barely a trickle.  I also didn't glue the long pipes down into the manifold, so they would pop off pretty quickly and kill the pressure.  I didn't want to glue them down so that they could be removed for getting out buildup (original purpose of this thing for me was a bottle washer).  I just stopped messing with the thing seeing how much additional work was needed to get it working.  And I haven't washed a bottle since  :-\

All Grain Brewing / Re: Efficiency: How Good is Too Good
« on: January 17, 2012, 10:32:09 AM »
Well, this is crazy....I just got a German pils in the fermenter. 12 lb. Best pils, 1 lb. Best Munich, target OG 1.042.  I got 10.5 gal. out of the mash at 1.044.  Promash tells me that's 99% efficiency.  I got 8.5 gal. of 1.051 in the fermenter.  Promash tells me 99% again.  When I do it by hand I get about 87%, much more believable.  I double checked all weights and measurements.

Maybe promash doesn't have the right malt analysis values, or is not handling the measured water volume properly?  IIRC Best Munich/Pils have a moisture corrected extract yield of 80% by weight, so at 100% efficiency you would have .8*13lbs=10.4 lbs (4.72 kg) of extract in the kettle.  You measured 1.044 (11 Brix) in 10.5*3.78 = 39.7L.  The mass of the mash is given by SG*Vol = 1.044*39.7 = 41.4 kg.  11% by weight is sugar, so .11*41.4=4.56 kg.  Therefore the efficiency is 4.56/4.72 = 96.5%. 

I don't have my spreadsheet handy, but this seems within the realm of possibilty on a 1.044 beer, maybe just a touch high.  Of course if the volume is off by a quart or if it is corrected to room temp, the effeciency would drop 3-4%.  I'm guessing you were in the low 90's on this batch.

All Grain Brewing / Re: Mash out questions
« on: June 16, 2011, 09:44:54 AM »
I also use a RIMS and its easy to set my heater controller to ramp the mash temp up.  I consistently measure several points Brix increase in the wort gravity with the mashout heating and recirculation.  Since its not a big deal for my system, I always do it.

This has been my experience as well.  There have been two or so batches where there was no difference in mash gravity (out of 20 sampled) before and after mashout, but most of them have showed a 1-2 brix increase after mashout. 

What I really want to know is if this same conversion happens as the wort in the kettle is heated to a boil?  Although the same thing would be happening the the enzymes as the temperature is raised, the starches that would be solubilized by the higher temp are still, presumably, in the MT, and therefore not exposed to the enzymes for conversion.

Good deal!  So on the strips at mash temp I'm still looking for a value of 5.2 - 5.5?  I might be thinking a bit to hard on this one.

You still want to shoot for 5.1-5.3 on the colorpHast strips regardless of the temp reading (I shoot for 5.0-5.3, which are the strip markings).  The decrease in pH of the solution due to increased temp is offset by an increase in apparent reading on the strip due to the chemical reaction of the litmus paper being affected by temperature.  The -0.3 systematic error inherent to the strips is still present and must be accounted for.  Also be aware that with darker beers the wort color can affect the color of the strip, so make sure to dab it with a towel before trying to read.

All Grain Brewing / Re: Electric stove-top: how far can you go?
« on: May 20, 2011, 06:45:43 AM »
I make all my beer on my electric stove.  Mostly 3gal batches with the occasional 4+.

Efficiency is largely about the bound water in grain (0.125qt/lb) as a percentage of the total water added.  If you want 3gal of concentrated wort from 10lb of grain, you could add 4.25gal of water in a no-sparge method.  We'll assume 90% conversion (I don't typically see 100%) of a 36ppg malt mix, so you'd have 10x36x0.9= 324points of sugar in your 4.25gal of water.  Since the grain holds 1.25gal, you'd get 3.0/4.25=70.6% of that sugar in your 3gal.  That'd be 3gal of wort at 229pts in 3gal or 76ppg.  Boil that then dilute in the fermentor to 5gal gal and you'd have a 1.046 OG beer.


Keep in mind that the apparent absorbtion (.125gal/lb or 0.5qt/lb) also includes volume contributed by the dissolved extract.  This makes the true starting volume larger, and the efficiency somewhat lower.  Extract contributes 0.63 L/kg (.303 qt/lb) of volume.  So in the example above the 10 lbs of grain is 36/46.214 = 77.9% extract by mass (10% less if you consider 90% conversion), *10 lbs = 7.8 lbs of extract, *.303qt/lb = 2.36 qts volume.  The efficiency then becomes 3/(4.25+2.36/4)=62%, leaving you with 3 gallons of 1.067 wort or 5 gallons of 1.040 wort, per your method above.

A two runoff sparge would be somewhat more efficient, which can be important when dealing with higher gravity beers.

same as above but split the water so that there are two equal runoffs:

strike water: 11 qt
absorbtion: 10*0.5 = 5 qt
runoff 1: 11-5=6 qt
sparge water: 6 qt
runoff 2: 6 qt

e1=vout/vtotal = 6/(11+2.36) = 44.9%
v_left = 11+2.36-6 = 7.36 qt
e2=vout/vtotal = 6/(11+2.36-6+6) = 44.9%
etotal=e1+(1-e1)*e2 = 44.9%+(1-44.9%)*44.9%=69.6%.

total collected: 6 qt + 6 qt = 3 gal
gravity: .696*324/3 = 75.2 points in 3 gal, or 45 points in 5 gal.

As far as how much a difference this is vs. a full volume boil, you could get about 88% efficiency with a two sparge collecting 7 gallons preboil, which would yield 5 gallons of 1.063 wort at the end of the boil for the same 10 lbs of grain.  Or to put it another way, you can get the same 1.045 wort by using 7 lbs instead of 10.  Not a great example, however, since you'd probably want to back off on the efficiency for quality reasons at this point.

General Homebrew Discussion / Re: Aging beer and hot summer days.
« on: June 25, 2010, 11:59:19 AM »
The rule of thumb in brewing (and lots of other chemistry) is for every 10°C increase in temperature, the rate of the chemical reactions that cause staling roughly double.  Dr. Bamforth said on the hot side aeration episode of Brew Strong that a beer that would stale in 3 months at 20C will stale in 1 month at 30C, 1 week at 40C, and 1 day at 60C.  Conversely, it can take 9 months at 10C.  He doesn't explain why these numbers are triple, not double those 10C cooler, but I guess is that it's not an exact rule of thumb.  Big breweries actually use this to test the packaged stability of their beer and see what it will be like however many months down the road.

Before I got into kegging, I used to store all my bottled beer in a 75F closet (24C).  Storing like this I noticed a slight amount of oxidation on some beers after 3 months, and a lot of it at 6 months.  A schwarzbier that has been in there over a year still holds up quite well, which a bit weird, but most everything else that has been in that long is not very good to drink, including an overly oxidized traditional bock and an autolyzed and oxidized maibock.

The other concern that homebrewers have that commercial brewers usually don't is the amount of yeast in the bottle.  That will eventually autolyze, releasing unpleasant flavors into the beer (think beef broth).  This happens faster at high temperature, just as aging does, so you want to be careful about the amount of yeast that gets in your bottles if you need to store warm or for a really long time.

IMO if you can only store the beer at 95-115F (35-46C) you'd be better off making batches small enough so that you can keep all the bottles inside, or get some sort of cooling solution like another fridge.  At that temperature it's going to stale before you can enjoy it.

Kegging and Bottling / Re: Epoxy Mixers in the Dip Tube ?
« on: June 25, 2010, 06:51:56 AM »
The resistance value of 3/16" is ~3psi/ft, simply divide the pressure by that value and it will yield the approx length of hose required to balance the system.

I'm not so sure about that.

My 5 ft line works pretty perfect at 10psi (w/o a mixer) which would mean it's closer to a 2psi per foot drop.  That is the value that I've seen most oftern during my searching.

I've also read that as you get in the upper psi range like around 30 the drop is < 1.  In other words the tubing resistence isn't constant with pressure.

Have you ever carbed a beer to 25psi and served it w/ 8-9' lines?

I agree, I've used lines that were much longer than necessary and it doesn't cause excessive foam, just a very slow pour.  You can see the difference if you hook up a long line and a short line back to back on the same keg.  The resistance of tubing is not a static value, it changes based on the flow rate.  If you pour slowly at say 80 oz/min the resistance is closer to .94 psi/ft, whereas a very fast pour of 192 oz/min would be more like 4.7 psi/ft (see this guide from the inventer of Ventmatic faucets (thanks to P-J for sharing this). 

When balancing a system you need to pour slowly enough so that carbonation does not come out of solution, and have enough resistance in the line to dissipate all the pressure at the regulator.  So a high carb beer hits you twice, first you need a long line to dissipate all the pressure at the regulator, and you need to pour slower so the resistance of your tubing decreases, necessitating an even longer line.  To avoid having 20+ foot lines, looks like the mixing nozzle is the way to go.

Another thing that can cause foaming is a clogged dip tube or a perforated dip tube, which sometimes happens if they crack.  Sounds like you got it sorted out though.

General Homebrew Discussion / Re: Lagering Times
« on: June 23, 2010, 10:43:30 AM »
I always go by taste since the condition of the yeast during fermentation and recipe is going to have a big effect on the answer in addition to the OG.  For example I had a dunkel that tasted great after 2 weeks, a Dortmunder that took 8 weeks, and a Bohemian Pilsner that took 5 weeks, all around the same OG.

Yeast and Fermentation / Re: Predicting yeast cell counts
« on: June 18, 2010, 05:52:37 AM »
The mr. malty calc has a limit to the amount of growth that it will recommend with one starter, that happens to be 6 yeast packages worth.  So if it would take over 6 of your 20% viable packages to ferment the batch (6*20=120 billion cells), it jumps up to a new minimum.  This isn't particularly useful since most of us don't have two or more identical old yeast packages lying around. 

The other limit the mr. malty calc places is a minimum starter size of 1L.  This is the generally accepted minimum for significant new cell growth in a WL or Wyeast package. 

For old smack packs or a small amount of slurry, doing a mult-step starter is what you want.  It will ensure that you have a timely fermentation at each step to minimize the risk of other microbial infection, as well as reduce greatly the required amount of wort needed to get to your final cell count.  The wort usage is reduced with a multi-step starter because there is a starter pitching rate that results in the maximum amount of growth, above which the growth rate declines.  For example, if your starter pitch rate is 100 billion cells/L on a stir plate, there will be 130 billion new cells grown per liter of starter wort.  If your pitch rate is 12.5 billion cells/L, the new growth will be only 57 billion cells/L.  You can see a plot of the mr. malty stir plate tab, the x-axis is the starter pitching rate and the y-axis is the starter growth rate:

You should size each step to remain within the 100-12.5 billion cells/L pitching rate, to ensure timely fermentation and always have the minimum number of cells needed for adequate growth.  The closer you stay to the high side of that pitching rate, the more efficient your wort usage will be, at least with a stir plate.  You can use the formula on the chart in a spreadsheet to estimate the growth from each step size, and don't forget to add the starting cell count to get the total after each step.  So for example if you have 20 billion cells and pitch at 100 billion cells/L, that's a 200 mL starter * 130 billion new cells/L = 26 billion + 20 billion (starting count) = 46 billion after step one.  Keeping the same rate for step 2, 46 billion cells into a 460 mL starter * 130 billion new cells/L = 60 billion + 46 billion starting = 106 billion after step 2.  You'll have to play with the starter sizes to keep the minimum pitch rate and not grow too many cells for what you need.

An alternate method for doing the math above is to have the calculator do it for you.  Input your recipe parameters and yeast viability and adjust the volume down until it recommends only 1 yeast package in the starter (remember the smallest it will recommend is 1L, so this is not the most wort-efficient sized starter).  The 'cells needed' result is the final cell count in this starter.  Next input this number into the viability field and adjust the recipe volume again until you reach either the desired recipe volume or the next step size to keep to 1 yeast package in the starter.  You can repeat until your final recipe volume is reached.  As your viability exceeds 100%, you need to be cautious that your pitching rate does not exceed 100 billion cells/L (e.g. if the 'cells needed' in a previous step is 150 billion, make sure you make at least a 1.5L starter in the next step.  You may need to adjust the intermediate starter sizes to make sure this is the case).

Kegging and Bottling / Re: Beer Gun vs. CP Filler
« on: June 17, 2010, 11:19:50 AM »
Kai, what's the longest you've kept unpurged tap-filled bottles, and what temperature were they stored?  How long did it take for oxidation to show up, if it has yet?  I'm considering this method to free up keg space since I don't have a special filler, and it will probably be the higher alcohol beers that require 6-12 months of aging. 

All Grain Brewing / Re: The Ideal Batch Sparge
« on: June 10, 2010, 11:09:33 AM »
I know this is a bit late, but I thought about running sizes and batch sparging a bit and came up with an analogy that makes sense to me.  Imagine that you have a kettle that always leaves 1 gallon behind when drained.  

That's exactly how I have modeled batch sparging on various occasions.


Yep, I've found your model to very accurately predict the into-kettle efficiency when all the starch is converted prior to the first runoff.  Since I got my refractometer inconsistencies sorted, my 3 most recent calculated efficiencies were within 1% of observed efficiency.  It's a very useful tool for recipe formulation and for seeing how much efficiency decline to expect when brewing bigger batches but collecting the same amount of wort.

All Grain Brewing / Re: The Ideal Batch Sparge
« on: June 10, 2010, 10:18:49 AM »
I know this is a bit late, but I thought about running sizes and batch sparging a bit and came up with an analogy that makes sense to me.  Imagine that you have a kettle that always leaves 1 gallon behind when drained.  So if you have 200 'points' of sugar and dilute it to make 5 gallons of wort, that's a 1.040 wort.  If the kettle is drained as much as possible, 1 gallon of 1.040 wort will be left behind, or 40 points out of a possible 200 (20%).  This is analagous to a no-sparge. 

Next collect the same amount of wort in two steps, first by collecting 3 gallons then collecting 1.  For the first runnings the wort will be 1.050 gravity, leaving 1 gallon behind.  Adding 1 more gallon of water will dilute the wort to 1.025, again leaving 1 gallon behind when drained.  So here you leave behind 25 points out of a possible 200, or 12.5%.  This is a single sparge with unequal runnings.

Finally, collect the same amount of wort in two equal steps.  This is done by a 3 gallon wort which is drained, followed by adding 2 gallons and again drained.  The first draining leaves 67 points behind, which is diluted to 1.022 by the second addition, and again leaving 1 gallon behind.  Here you leave behind 22 points, or 11%.  This is a single sparge with equal runnings.   

You can see the difference between equal and unequal runnings (1.5%) is relatively small even for a large difference in runoff sizes.  The size of the 'dead space' at the bottom of the kettle can be represented in your MT by the amount of wort absorbed by the grain and any dead space, easily measured on your next batch.

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