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Messages - mabrungard

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Equipment and Software / "Varnish" in Fermenter
« on: January 25, 2015, 11:52:56 AM »
I just noticed an interesting buildup in my stainless conical fermenter.

I thought I had been keeping my fermenter perfectly clean for over a decade, but I noticed prior to my last brew that it had a very light tint on the interior surface. Since I spent days polishing the interior of the fermenter when I bought it, I have always avoided hard scrubbing with scrubby pads. But I have always been thorough in scrubbing the surface with either my hand, thumbnail, or sponge to remove any sort of trub, yeast, or other deposits. It always looked clean and shiny.

So with some 60 or 70 batches fermented in that vessel, I happened to notice that there was a tint to the stainless surface. I used my thumbnail and was able to scrape it off...grudgingly. It was some sort of a transparent, tan coating that I guess could be termed "varnish".

I still didn't want to use a scrubby since that is known to create micro scratches in metal surfaces. So I tried a warm PBW soak. That helped a bit, but I'm pretty sure that it's ~110F temperature was not enough to really activate the solution. I then hooked up my RIMS and circulated the solution at 160F and it further loosened the layer. I could get more off with my nails. Ultimately, I pulled out a white scrubby and lightly scrubbed the surfaces to get all the varnish off.

It's clean now, but I have to wonder if critters may have been lurking in that microscopic varnish layer that may not have been knocked out with sanitizer? Fortunately, my prior beers have been good, but that question has to remain.

While this event hasn't diminished my avoidance of harsh scrubbing with a scrubby since its obvious to me that the micro scratches will eventually become filled with that varnish, I wonder if anyone else has experienced this?

The good news for me now is that I know that I need to perform a substantial PBW cleaning in order to remove something I can't even see, on a frequency a little greater than once in 60+ brews.   :)

All Grain Brewing / Re: Grain Mill Gap Setting
« on: January 24, 2015, 12:02:19 PM »
But Ken there's no guarantee that my settings would have any bearing on anyone else. 

So true Denny. As you have said before, the speed of the mill also has an effect on the crush quality. You said that faster milling speed produces finer crush. I agree with that. I gap a 0.035" and milling slowly with a 1/2" low-speed drill. That works for me, but someone else could easily find it unacceptable for their system.

Yeast and Fermentation / Re: Faster Finished Beer
« on: January 24, 2015, 11:41:31 AM »
Well, sort of. Yes, colder beer will absorb CO2 quicker. But that is just the first part of carbonation. The second part is the hydration of the dissolved CO2. Since it is a chemical process, I am pretty sure that it will proceed quicker when the beer is warmer.

I think that most of us recognize fresh carbonation. The bubbles are big and coarse, just like at the soda fountain. It takes time for the carbonation, that we can easily inject into the beer, to hydrate and produce those nice fine bubbles that we prefer in our glasses.

So it seems to be a balance between time and temperature for carbonation. In my experience, it still takes about 2 weeks to get the fine bubbles in beer. But you can still enjoy that beer with coarse bubbles in the interim.

All Grain Brewing / Re: Mash pH
« on: January 24, 2015, 06:27:30 AM »

If you're worried about your mash ph not getting to 5.2 you can buy this stuff. Works great!

Wow Mike! This is great news. We have been waiting for a brewer to come forward with proof that this stuff works. Please post your pH meter readings.

Yeast and Fermentation / Re: how long on the yeast cake
« on: January 22, 2015, 07:55:29 AM »
Certainly a couple of weeks will not be a problem as long as your beer is kept reasonably cool. So no reason to be concerned.

Are you aware that there is scientific research that shows that it only takes 2 to 3 days to produce the full effect of dry-hopping? You could easily reduce your contact time significantly.

Equipment and Software / Re: Going electric
« on: January 21, 2015, 07:19:17 AM »
This is the kettle controller that I recently installed in my system. It works very well and is nicer than the pulse-width modulator that I formerly used.

Ingredients / Re: Brun' Water profile for Barleywine?
« on: January 20, 2015, 03:51:45 PM »
No, I recommend including the extra sulfate of the Bitter profiles. Here is the reason why:

There is a history of big beers and sulfate. Before the advent of IPA, Burton was actually known for their big beers, most notably, Burton Ale. It was essentially an English Barleywine and noted for its pleasant finish. They also made beers for the Russian Imperial court.

The extra 50 ppm (or so) sulfate that the Bitter profiles call for is minor in comparison to the sulfate level that was likely in Burton waters (somewhere between 300 and 800 ppm). So I contend that the drinker of a English or American Barleywine will not notice much difference, but should welcome a little more drying in the finish that should help balance that big malty finish that will be present in those big beers. 

Equipment and Software / Re: Going electric
« on: January 19, 2015, 07:30:44 PM »
You really don't need that much in the way of watts. For 7 gal, I'd say that something in the 3,000 watt range will create a good boil. However, I do use 5,500 watts and that brings the wort to boil quicker. I do use a pulse width modulator to cut the power down after reaching a boil though.

Ingredients / Re: My water's been sitting
« on: January 19, 2015, 02:18:46 PM »
RO can leach ions out of the stainless steel, but it is at a very low rate. RO is not officially corrosive to good grades of stainless steel. The biggest concern I see is for those wanting ultra-pure water...if you keep it in stainless steel, there will be a very low concentration of the steel components in the water.

Ingredients / Re: My water's been sitting
« on: January 19, 2015, 01:00:31 PM »
RO permeate is a fancy term for the RO water that we use. It has permeated through the membrane and left most of those ions we don't want, behind.

There is also the RO reject water. That is the water that couldn't make it through the membrane that has all those excess (now concentrated) ions.

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:

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.

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.

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 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.

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?

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.

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