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Messages - tschmidlin

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7861
Yeast and Fermentation / Re: Culturing up a pitch from bottle dregs
« on: August 27, 2010, 10:53:49 AM »
Tom,
What do you think about doing the first and second step ups for a big starter with a glucose/dme mix and then the final starter with all DME?  I have been considering ways to reduce the cost of making large starters, short of doing a mash just for starter wort.
That will be totally fine, although I'm not sure you even need the mix.

Basically, high levels of glucose repress the expression of maltase regardless of the presence of maltose, and it happens quickly - in less than 20 minutes IIRC, the levels of maltase are falling.  The yeast will preferentially ferment the glucose, then when that drops below some threshold they will turn on the maltase genes and go after the maltose.  So by doing a mix for the first couple of steps they'll essentially be yo-yoing between the two sugars.  This is not especially stressful for the yeast though, they're fine - the only difference is the expression of all of the maltase genes.  I don't remember how many there are in the cascade . . . ok, according to SGD there are 10 that are directly involved in maltase, but only 2 are the actual enzymes themselves.  But that doesn't include all of the genes needed, because there are maltose permease genes.  Anyway, I wouldn't worry about these details much, I just thought you'd be interested.

Bottom line, supplementing your starters with glucose is fine, especially if the last step before pitching is all DME.  You could use sucrose (table sugar) for that matter, maltase can invert that too, it's cheaper than glucose, and won't suppress maltase the way straight glucose does.

7862
Zymurgy / Re: 2010 Sept./Oct. - Batch Sparging
« on: August 27, 2010, 10:18:03 AM »
And then one day soon at a nice picnic you'll be standing their admiring your 70 qt cooler and you'll start thinking, "I could just put a little braid in there..."
I mash in a converted keg though, so there's really no need to change.  Although it would fit more grain . . . or if I wanted to do a second mash . . . :)

7863
Yeast and Fermentation / Re: Culturing up a pitch from bottle dregs
« on: August 26, 2010, 11:38:01 PM »
I'm a grad student getting a PhD in Biochemistry and have done a lot of work with yeast.  Our standard media is 2% glucose.  I propagate all of my fermenting strains with the same formula and have had great success growing stuff out of bottles.

Unfortunately though, between grad school and kids my brewing schedule is chaotic and I never know very far in advance when or what I'll be brewing, so I usually don't have time to pull something from the -80 and grow up a pitchable quantity.  And if I do have time for that, I normally don't have time to do cell counts or stain to check viability.

But I will say this; 2% glucose is research standard growth media for a variety of reasons.  One is the suppression of the crabtree effect, which will help the yeast stay healthy - face it, ethanol is bad for them.  Another is that glucose is easy to ferment, and if you're just trying to grow mass you want it to be easy on them.

That being said, I always use DME for my starters, never glucose.  You want the yeast to already have made and be making maltase when you throw them into your beer, it decreases the lag time.  Some people say that yeast grown in glucose lose the ability to ferment maltose, which is really incredibly unlikely unless you do it for a long time.  But they will take longer to get going, because glucose represses the expression of maltase so first they have to switch the maltase genes on.  So always feed your yeast maltose before putting them in your wort.

7864
Beer Recipes / Re: New Glarus Crack'd Wheat
« on: August 26, 2010, 11:13:18 PM »
According to Stan, the primary temp and time are proprietary, the yeast is Bavarian Weizen, it has pilsener, wheat, and caramel malts, 36 ibus, and is hopped with hallertau tradition, cascade, and amarillo.  OG 1.053, 6% abv, 86% ADF.

There's more info scattered throughout that you might be able to glean some information from, so it's worth getting your hands on a copy of the book I think.

7865
Extract/Partial Mash Brewing / Re: Sour ales
« on: August 26, 2010, 10:08:48 PM »
Actually i might have missed something. I thought making these was basically the same as any other beer. How long to they take exactly?
They're done when they're done.  You'll have to rely on your taste buds to tell you when they've hit the level you want.  The Saccharomyces will be more or less done in a couple of weeks, the Brettanomyces generally takes longer to get the flavor development most people are going for.  The Lactobacillus can work pretty quickly, given the right conditions.  I've aged my Flanders for over 2 years at times, but you generally don't need to wait that long.  One year is enough time usually, and some people do well with 6 months or less.

I have heard that about the plastic. So it is not true for glass, right? I can use the glass for different beers?
The glass should sanitize fine.  The plastic should too if it's sound tubing, but it's really not worth the risk.  Invisible cracks are like canyons to the critters.

7866
Extract/Partial Mash Brewing / Re: Cursed at 1.020
« on: August 26, 2010, 10:00:08 PM »
Is it true that corn sugar ferments better (more) than table sugar?
Corn sugar is glucose, it is easily transported into the cell and broken down.

Table sugar is sucrose, which is a disaccharide of glucose and fructose.  The yeast first has to break the bond between the two units (although this happens by itself at some rate under acidic conditions), then break them down further.  But both of the subunits are easily broken down by most yeast.

7867
Yeast and Fermentation / Re: Culturing up a pitch from bottle dregs
« on: August 26, 2010, 09:47:03 PM »
You should definitely do it.  If they make a beer that you think might have less stresses yeast of the same variety try culturing from that, but even still it's worth a try with what you have.

If you are really worried that the yeast is stressed, make a light starter, as little as 2% DME, so 2 grams in 100 ml of water.  You should definitely supplement with nutrients, the proportion will depend on what nutrient you're using.

Daughter cells from stressed mothers will themselves be weak, but the nicer the conditions the faster subsequent generations will recover.  The packaging and shipping conditions will have selected for cells that are best able to survive those conditions, but that doesn't mean that they will be so mutated as to be wildly different from the fermenting strain.

If you've made plates before, I recommend them for yeast culturing from bottles.  It is nice to just dump some dregs on the plate and look for what grows.  From there you can streak to other plates and pick a nice looking colony.  A plate recipe is the same as your starter recipe, just with some agar added (available from morebeer.com).

7868
Zymurgy / Re: 2010 Sept./Oct. - Batch Sparging
« on: August 26, 2010, 09:07:40 PM »
Amazon has the 70 qt xtreme for $40 and free shipping right now:

http://www.amazon.com/Coleman-70-Quart-Xtreme-Cooler-Blue/dp/B000G64I1A/ref=sr_1_2?ie=UTF8&s=sporting-goods&qid=1282877033&sr=8-2
The 100 quart one comes with wheels, $75.  You could probably fit 75 lbs of grain in that!  ;D  I've been needing a new cooler anyway, and I'm a fan of the wheels.  According to coleman.com, it's got the drain channel too.
http://www.amazon.com/Coleman-100-Quart-Xtreme-Wheeled-Cooler/dp/B000G64FJK/ref=pd_luc_sim_01_02_t_lht1

But I think I'm going to get the 70 qt one and see how it goes.  I actually intend to use it as a cooler, not as a mash tun!  :o

7869
Kegging for me too, and probably looking for a leak in my CO2 system.  Maybe clean some kegs.  Who knows, the list of things to do is pretty long :)

7870
Kegging and Bottling / Re: Fermenting is done!!
« on: August 26, 2010, 01:50:34 PM »
I can only go to 20psi, cause I am using a 20lb tank...So at 20psi, I think I will pour beer out of it in 2 days, and keep trying it until the desired carbonation is reached.
The size of the tank has nothing to do with how high you can set your secondary regulator.  If your secondary regulator only goes to 20 psi, then that's as high as you can go.  If your secondary reads to 30 or 60 psi as many of them do, but you can only get 20 psi out of the tank, then your tank is probably almost empty.  What does the primary regulator say?

CO2 tanks have liquid in them when they are full, and maintain a fairly constant pressure inside the tank as long as the liquid is there.  The pressure they have depends on the temperature of the tank.  PV=nRT  R is a constant.  In the tank, volume (V) is mostly constant, but a you use the gas the V will increase over time as the liquid turns to gas.  n is the amount of gas, which will increase slightly as the volume increases.  The temperature you keep the tank can vary, so this will affect the pressure of the gas in the tank slightly, but as the pressure increases the gas is more likely to turn into liquid.  So anyway, the bottom line is that as long as there is liquid in the tank the reading on the primary, high-pressure, gauge will remain pretty much where it started.  It is only when the tank is empty of liquid that the needle on that gauge starts to move.

Yes, you can turn up the pressure and carbonate it faster, but like svejk said, you have to catch it at the right point.  Over-carbonated beers are a total pain to deal with, so I don't recommend turning it up that way.  Your choice though . . .

If you're in a hurry, the better way to do it in my opinion is to set it to the pressure you intend to serve with, then shake the keg vigorously and repeatedly for as long as you can take it.  Take a break and then do it some more.  It takes some energy and you'll probably work up a sweat, but there's no danger of over-carbonating with this method.  And it can be a good workout. :)

7871
The Pub / Re: Let it be known.....
« on: August 26, 2010, 10:01:55 AM »
OMG! 14+ posts a day!?
What? :)

I sit in front of a computer 12-15 hours a day, starting jobs and waiting 5 minutes to 72 hours for them to finish.  Check the results, start more stuff.  That gives me lots of time for reading random stuff online.  It used to be the news, now it's the forum.

Bring it on Drew, I can take it.  I think.  :)

7872
Other Fermentables / Re: Mead and Potassium Hydroxide (KOH)
« on: August 26, 2010, 09:53:11 AM »
The potassium is beneficial to live yeast but will not help dead ones.
Hilarious!  ;D

7873
My argument being that marking things up 50% or better over your competition and expecting your customer base to support this out of goodwill is bad business, not that all LHBS are bad businesses.
I agree, that's bad business.  I assumed you were referencing one shop as a bad business, not LHBS in general.  I wouldn't expect anyone to support a shop where they don't like the owner, the staff members are rude, the prices are exorbitant, etc.

Sounds like we agree.   :)

7874
General Homebrew Discussion / Re: Your Homebrew Name
« on: August 26, 2010, 09:24:09 AM »

7875
Extract/Partial Mash Brewing / Re: "Black I.P.A" recipe
« on: August 26, 2010, 09:17:05 AM »
Oh, one more question. I'm having trouble finding a local Homebrew supply store with Alexander's LME. Can I use a substitute?

Yes, you certainly can.
Dur.  Of course you can!  I misread it and thought he was looking for a recommendation on a substitute.  My bad.   :-[

Thanks Denny.

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