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Messages - mabrungard

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781
Yeast and Fermentation / Re: rehydrated dry yeast temperature shock
« on: January 17, 2015, 01:05:18 PM »

They recommend 105 degrees in Yeast, though I think some manufacturers recommend closer to 95 degrees. 

This is interesting though: http://seanterrill.com/2011/04/01/dry-yeast-viability/

The thing that could easily catch many, is for the water temperature to be too hot and the cells being killed on contact. Without a thermometer, it could be difficult to say the water was cool enough if you aiming for 100 or 105F. You just know its warmer than body temperature. However with certainty, I can tell when water is colder than body temperature. It just seems like an appropriate safety precaution.

I had not seen Sean's work on this subject. Just what I expect from the orange-hatted one. That work points to exactly what I contend, plain cool water is a better method.

782
Yeast and Fermentation / Re: rehydrated dry yeast temperature shock
« on: January 17, 2015, 10:53:56 AM »
I'm surprised to hear a recommendation to rehydrate at 100F. While I do boil my rehydration water to help sanitize it, I do let it cool to room-temperature before adding the dry yeast.

I've done unscientific trials on hydrating and not hydrating and have come to the conclusion that I get significantly better performance when I hydrate the yeast. I can understand that you could easily screw up the rehydration process by not properly working with the water, but I still think that we are better off with rehydration. The reduced osmotic stress placed on the yeast due to rehydrating with plain water just makes sense to me. Sugar-filled wort places more osmotic stress on the yeast, and I can imagine, does reduce the overall viability and numbers for the yeast pitch.

783
Yeast and Fermentation / Re: Right RPM for stir plate?
« on: January 17, 2015, 08:37:25 AM »
"My problem with stir plates is that they, like yeast rinsing, have been sold to the home brewing community based on faulty information.  A stir plate is a poor investment when used with an Erlenmeyer flask and a stir bar.  This setup has been sold to home brewers as a self-aerating, "set it and forget it" way to propagate yeast.  The craziest thing is that brewers who arrived on the scene after the introduction of stir plates have been taught that starter media is always too foul to pitch.  Foul smelling media is a sign that the yeast cells in one's starter are stressed."

...


"My post was meant to bring attention to the fact that temperature-controlled fermentation chambers are one of the first things that are pushed onto new brewers when they inquire about process improvement, not that there is never a need for temperature control.  More often than not, quality control problems have little to do with whether or not not a brewer is using tight or stepped temperature regulation during fermentation, especially when using a yeast strain that is as forgiving as BRY 96, which is the most popular yeast strain in home and craft brewing by a sizable margin.  The number one thing that will hold brewers back from producing quality beer is less than optimal sanitation."


Mark, I see that we agree on the uselessness of trying to propagate a starter without adequate oxygen. Aerobic conditions are REQUIRED for the yeast to synthesize sterols and just putting yeast in a narrow-ended flask is not going to keep the starter aerobic. Nor is a shot of oxygen, once or occasionally. I found that since the need for oxygen in keeping starter wort aerobic is relatively low, the use of air is OK...as long as its filtered adequately to prevent contamination. I understand that filtering at the sub-micron level should be sufficient to remove air-borne contaminants. I also found out the hard way, that using an air-stone for starter aeration is NOT required. Just pumping filtered air into the headspace over the starter wort is adequate. That should keep that headspace at over 19% oxygen content and that should easily transfer to the wort. I have to admit that my apparatus may be better suited for that transfer since I create 1 to 2 liter starters in a 6 liter ehrlenmeyer flask. That leaves a large surface area between the headspace and wort.

Mark, I have to point out your experience with the importance of temperature-control is biased. A basement in a home located in the northern US is actually a nicely temperature-controlled environment that is truly an advantage compared to those that live in a hotter climate and don't have a cool basement. You forgot to take of your blinders on that issue. While I am in the same situation as you...with a nice cool basement...I remember my days in Tallahassee and the dire need for temperature control then. For most brewers, temperature control is a critical step in producing high-quality beer.

784
Yeast and Fermentation / Re: Right RPM for stir plate?
« on: January 16, 2015, 01:42:14 PM »
Wow! What a great thread that is hidden under this crappy title. I had not considered looking at it until now and am glad I did.

First to the OP's question, I agree that the proper stir plate rpm is that which keeps the yeast in suspension. There is no need or advantage to high rpm and a frothy vortex.

Mark, you have incredible knowledge shared here. I agree that a stir plate is not ideal, but I don't think that its terrible. One thing that is true, is that a stir plate alone is not sufficient to keep a starter aerobic when using typical narrow-ended vessels. There is little chance that there will be enough exchange with the normal atmosphere to transfer enough oxygen. That is why I flood the headspace of my starter flask with ambient air that is filtered through a 0.45 micron filter. That way, I know there IS enough oxygen present in the headspace to transfer into the gently-stirred wort below. Mark, is your problem with stir plates the fact that they aren't keeping the wort aerobic...or some other reason?

According to (Verstrepen KJ, et al.Yeast flocculation: What Brewers Should Know.” Applied Microbiology and Biotechnology, Vol 61, pp 197-205, 2003.), flocculation is generally inhibited during active fermentation by the presence of mannose, maltose, glucose, and sucrose in the wort. So that means that if the yeast tend to quickly settle when you stop stirring, the wort is exhausted. With the information in this thread from Mark, I now know that I should get that starter into the fridge to settle for decanting. I have probably been continuing the stirring for too long. I'll revise my procedures.

Mark, I read your contention that temperature control is not that important. But I'm concerned that your example yeast species may not be a true case in point. While it apparently works for that relatively clean fermenting yeast, I'm curious if that result can be applied across the entire yeast spectrum? I anticipate that it can't. Can you expand on that?

785
All Grain Brewing / Re: Water Chemistry
« on: January 16, 2015, 12:52:52 PM »
any feedback on calcium levels and if there's any  negative effects at higher levels?

In ale brewing, there doesn't seem to be too much detriment to brewing with high calcium content. One aspect that may be either good or bad, is that yeast flocculate and settle much faster with high calcium content. For example, Burton beers were always praised for their clarity. But a negative would be if your ale yeast flocs too quickly and your beer doesn't attenuate and you have to somehow rouse the yeast to get it to finish its job!

In lager brewing, there definitely is a negative to high calcium. It can interfere with the yeast metabolism and can cause premature flocculation (as above).

In general, calcium doesn't really affect flavor. Its the other ions (Cl, SO4, HCO3) that affect flavor. 50 ppm Ca seems to be a minimum value for ales since you may have problems getting the beer to clear quickly at levels lower than that. Lagers don't have to clear quickly since they are 'lagered' and that slow process does the work. Of course, this whole clearing issue is easy to fix...either fine, filter, or centrifuge the beer to remove the yeast.

AHA members will get to read more about this calcium in brewing water in the March/April 2015 issue of Zymurgy. It helps put to rest the myth that brewing water should always have at least 50 ppm calcium.

786
All Grain Brewing / Re: Water Chemistry
« on: January 16, 2015, 06:36:55 AM »
The RA is probably not too out of line. A slightly negative RA is probably OK since an IPA grist is probably not that acidic unless it includes a bunch of crystal. Remember, this profile has a decent amount of alkalinity and that balances the high hardness from the Ca and Mg.

The SO4-2 is just indicating the valence charge for the ion. Notice that Ca and Mg are +2, Cl is -, etc.

I think the original profile was OK, except for the Cl was a bit higher than I would target. The 200 ppm SO4 should be a good starting point for exploring how you like sulfate in your PA's

787
Equipment and Software / Re: Beer Stone (maybe)
« on: January 13, 2015, 07:18:34 PM »
I've noticed a whitish film building up on the interior of my new stainless fermentor (and also a bit on the dip tubes of my corny kegs). 


What is your water like and what calcium level do you typically target in your brewing?  Just looking for data points on beerstone.

788
Ingredients / Re: Water profile for ordinary bitter
« on: January 13, 2015, 07:06:57 AM »
I agree that Yellow or Amber Bitter should be well suited for an English Bitter since it includes a very modest level of sulfate that provides only minor drying in the finish. I made a pale ale last year with only 100 ppm sulfate, down from my normal 300 ppm and found that the finish was definitely fuller and much less drying. That should be well-suited to the typical flavor I find in Bitters.

789
All Grain Brewing / Re: Sparge Water Volumes
« on: January 10, 2015, 02:27:10 PM »
I just stop collecting runoff when I reach the proper volume in the kettle.

Jeff, that's what I've gotten in trouble with in the past. Apparently with my new system, I can now deplete my grist of sugars well before I've reached my desired kettle volume. But, I'm still getting 88 to 92% efficiency.

I'm going to switch to more closely monitoring my runoff gravity and reserving about a gallon of the calculated sparging volume. I'll only add more water to the tun if the runoff is plenty high. That remaining sparging volume will be added directly to the kettle to reach my desired pre-boil volume from now on. We'll see how this approach works out since I've been experiencing low level tannins in my beers with my new system and I have to do something different.

790
Kegging and Bottling / Re: Air distribution manifold expansion
« on: January 09, 2015, 02:32:53 PM »
You can do anything you want. Use the plugged port or add wyes and tees to any of the other ports or valves. Nothing sacred there.

791
Equipment and Software / Re: Ventilation for Indoor Brewing
« on: January 09, 2015, 12:38:01 PM »
This is what I created. 6" blower, plexiglass, and wood. The plexiglass lets in light from the overhead light so I can see in the kettle better. All electric brewing system.


792
Yeast and Fermentation / Re: Dry yeast for pre-soured Berliner Weisse
« on: January 08, 2015, 03:37:30 PM »
Mark, you could have a point with that K-97. I'll have to try that.

793
Yeast and Fermentation / Re: Best dry yeast for a scotch ale?
« on: January 08, 2015, 03:32:54 PM »
I used S-05 for a Scottish 70 last year and it was great. This was based on the recommendation from Jamil to use 1056 in that class of beers.

794
General Homebrew Discussion / Re: Bock attenuation problem
« on: January 06, 2015, 08:42:59 AM »
Well, here's your problem right here. you probably mashed too high. I wouldn't have mashed higher that 152. In fact, 148 would not have been too low. And a couple pound of pils malt will help insure that you have the enzymes necessary to compete conversion and dry your beer down where you really want it.

Too many brewers make the mistake in thinking "more body, more better" - these beers have plenty of body. The trick isn't getting them to have enough body. It's getting them dry enough so that when you finish the first beer, you really want a second. That's really the key with every beer. And rarely is there ever a reason to mash at 155.

+1 to what Keith says above. This is a significant factor to the underattenuation that I commonly detect in judging. Too many brewers focus on body instead of fermentability and they end up with nice and chewy beers, but they don't attenuate and each sip ends up coating and cloying the palette. I rarely find that I want to finish the glass... much less, order another round. Drinkability is an important feature in great beers. Avoiding an overly high mashing temperature is the first step to drinkability in my opinion.

I started out 15 years ago targeting mash temperatures of 155F and higher. I've learned that keeping the max temperature around 152F does produce more drinkable beers for me.  Another thing to consider is the duration of the mash. Both time and temperature are components in fermentability. Only in the smallest of beers do I bump up temperatures or shorten the mashing duration. 

795
All Grain Brewing / Re: Sparging Water Volume
« on: January 04, 2015, 05:26:05 PM »
Jeff, you raise an ominous specter. Now I'm going to have to do some cross-checking on my refractometer too. As mentioned, this may be more reason to end the runoff earlier.

Extra testing for the next brew.

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