Hey Fraoch.... I'm baaaack !

Discussion and topics about BeerTools.com online calculators and other tools.

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Mesa Maltworks
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Hey Fraoch.... I'm baaaack !

Post by Mesa Maltworks »

I'm not dead !!! I had problems with my DSL connection with the net that recently got resolved, so I'm watching again ! Sorry for the absence.

Eric
stumpwater
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Hey Mesa!

Post by stumpwater »

Glad to know that you are back. I was wondering if you could review the threads on the Hot Weather Green Apple Blues and review my conclusion? I would really appreciate your opinion.
Freon12
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While you are here.....

Post by Freon12 »

I am advising a micro brewery on the subject of glycol chillers for the production and crashing of beers. I am an expert in refrigeration but not in beer production, would you be interested in reviewing our plans for equipment selection as a consultant? If so, reply to me at harleyheritage@netzero.net Thanks in advance.
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Mesa Maltworks
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I tried... but....

Post by Mesa Maltworks »

I tried to send the following to the supplied E-Mail address, but it kept getting returned so here it is:



I would be happy to help with your project. Your refrigeration experience is just as applicable, but instead of air to air (coolers or freezers) or air to water heat exchange (ice makers/chilled water) or water to air heat exchange (geothermal) it is glycol/water solution to water to wort heat exchange. As you probably know, in HVAC, you are looking for a minimum 20 degree delta from the ambient temperature to achieve proper cooling. In a wort knockout application, your delta has to be MUCH greater as you are cooling a moderately dense fluid (in comparison to water) from ~208 F to 43~45 F (Lagers) or 52~63 F (Ales). ((A side note: if you find these knockout temps on the low side, you are leaving out the fact that once yeast enters full logarithmic fermentation, they typically cause the wort to warm by 9~12 degrees, that is why you want to knock out below your actual fermentation temperature.)) Complicating the calculation are the inputs from variables such as flow rates of either/or/all the following: glycol/water, the water, the wort and the water temperature !

If the system you are evaluating is from a source that is still in business, I would recommend getting the "as-built" drawings from one of their installations of a like system. The drawing will usually specify the manufacturer of the exchanger and it's assembly number. You can use this info to back-track the appropriate exchanger choice through the OEM.

I would not leave anything to chance on this topic. If the glycol reservoir, the chiller or/and the supply lines are not sized properly, the system will either barely work for the warmer styles or won't work at all.

Notes from installation experience: DON'T USE PVC COUPLINGS TO MATE THE GLYCOL OR WATER LINES TO THE HEAT EXCHANGER ! Use stainless or brass. This will greatly reduce the chance of leaks because the metal in the couplings expands and contracts at a rate similar to that of the fittings on the exchanger. This rule also applies to connections made to fermenter jackets. ALSO: Use Schedule 80 PVC rather than Schedule 40, NEVER use vinyl hose for glycol supplies in a brewing applications and insulate all glycol lines to retain performance.

Let me know more specifics related to your project and I can try to help further.


Eric Watson
Head Brewer
B&O Station Brewery & Restaurant
(Formerly The Ohio Brewing Company)
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Mesa Maltworks
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Location: Georgetown, Grand Cayman Island

Green Apple Flavor = Either Acetaldehyde or /and Bacteria...

Post by Mesa Maltworks »

After reviewing the replies to your original post, I have a few comments:

1) One of the postee's confused this flavor with that displayed by "skunked" beer. Actually, this flavor is produced by photochemical reactions with hop compounds that lead to the production of aromatic sulfur compounds. Some lager yeasts also produce a similar, but cause unrelated sulfur note as well. With the yeast caused sulfur, it is easily removed from the beer by bubbling CO2 through it. You can actually smell it coming out of the beer and stop underletting it when the aroma dissipates !

2) Other perceptible flavor defects are also caused by acetaldehyde with the resultant flavors being described as fresh cut grass, green leaves and latex paint.

3) Although a component of the "green beer flavor" that in low concentrations is usually re-absorbed by the yeast, acetaldehydes that impart a lingering, permanant flavor is usually created from another source. Most beers with normal pre-secondary acetaldehyde levels loose the flavors throgh the reduction of the acetaldehyde to ethanol by yeast during the secondary fermentation.

4. Possible causes:

a. You harvested the beer too soon from contact
with the yeast in the secondary prior to the
acetaldehyde being re-absorbed.

b. The beer was packaged with the presence of
excessive oxygen. Here's a weird fact
about beer microbiology: All of the
acetaldehyde that was re-absorbed by the
yeast can return upon oxidation of beer.
Simply stated, the ethanol that was
produced by yeast metabolizing the
acetaldehyde may revert to it's old self !
So... watch your packaging airs !!!

c. Confusing the issue, a similar "green
apple flavor" can be produced by spoilage
by the bacteria Zymomonas or
Acetobacter. The most common of these
meanies to grab your beer is acetobacter
as it is extremely common in most
climes. In low levels, especially with
briefly aged beers, the acidic note that
acetobacter can lend to beer gives a
more "sour" type flavor than the presence
of acetaldehyde alone. In high levels,
acetobacter will totally wipe out any
acetaldehyde flavors as the flavor
becomes markedly acidy and often winey.

There is an easy way to train you palate
for acetaldehyde detection... drink a
(gulp!..) Budweiser ! Anheuser-Busch
intentionally targets an acetaldehyde
level that is barely above the threshold
for detection. It is imparted through
their use of beechwood chips to accelerate
flocculation (ie... less yeast contact
time with the beer). If you pay close
attention, you can detect a light, almost
sweet green apple flavor. To a lesser
degree, you can also taste this affect in
Rolling Rock, but it is much harder to
detect due the elevated levels of
DMS, which in this beer, is also
intentional. Now if you can't taste this
in either beer, don't think something is
wrong with your palate. The Bud level is
very low and the RR level is only somewhat
higher. Just like with diacetyl, a
certain percentage of the population
cannot detect these compounds unless they
are really high.

Hope this helps !


Eric
Freon12
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try once more

Post by Freon12 »

I e-mailed myself using the posted address and recieved O.K. Dsl still fuzzy? Anyway-
I will eventually learn to be more specific with you Eric, sorry. I don't think Jeff will mind if we use the forum for this, beer related and all.
I mean to say I am an expert in glycol and chillers in this application, and we will provide the new equipment using 35% Glycol. I think I need you for advice on process logistics and crashing ales by switching the loads from one system to the next using different jackets, Maybe a two stage system design will do. Also I would like streamline ideas for process, plus I thought you would like to meet Ed Herman from Upland brewery, and Brooke Belle from the Oaken Barrell brewery while you were out and about.(possibly a sample or two to take back) I can provide the phone numbers for both if you wish. Let me know your fee for such a road trip, and the company will pay to bring you out for a day to Bloomington and Greenwood, IN.

Steve Mangum
(317)716-8355
CEO
Concept Technologies Inc.
3100 Meridian Park Dr.
Greenwood, IN 46142
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Mesa Maltworks
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Reply E-Mailed to last post...

Post by Mesa Maltworks »

I re-tried
E-Mailing you, hopefully it got through. If not, let me know here.

Eric
Fraoch
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good to see....

Post by Fraoch »

Welcome back Mesa, I see you are as popular as ever. Fraoch
Freon12
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Location: WHITELAND, IN, US

Nope, no luck

Post by Freon12 »

I have not recieved anything. I sent you one to reply to, hope it goes.
S.
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