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Mythbusters

Post #1 made 15 years ago
by hashie
Inspired by this topic, specifically post #86. I thought we needed a dedicated thread for myths, misnomers and other related wrongs (or rights).

As discussed in the above thread, there is talk about sparging. Do we need it in BIAB, does it give any improvement to the finished beer or to the efficiency of the mash?

My personal thoughts are that it is not needed at all, assuming your pot is large enough to do a full volume mash.
With a full volume mash all of the liquor needed is in the pot from the outset. All of the liquor is in contact with the grains for the maximum amount of time (the length of your mash) and, if you mashout, all of the liquor is at a higher temperature and in contact with your grains.

If we were to sparge, the amount of sparge liquor we need needs to be subtracted from the mash liquor, heated in a separate vessel and then used for sparging, perhaps in another vessel again. I simply don't see the point or need of doing this.

Not sparging with BIAB, in my opinion, is the most sensible and simple method which gives a better more consistent result.

Same amount of liqour, same amount of finished beer, one vessel, easy peasy.
Last edited by hashie on 02 Nov 2010, 05:26, edited 5 times in total.
"It's beer Jim, but not as we know it."

Post #2 made 15 years ago
by Ralph
I can see your point hashie, I advocate a sparge in one circumstance: MaxiBIAB where brewlength > kettle volume, and where extracting the last few litres- worth of beer (nb. not wort) out of that mash makes the difference. Even then, it isn't completely necessary though, the grainbill can always be increased even more, I just haven't tested that extreme, but I do intend to at some point.
Sparging is common in stovetop BIAB where the cheap equipment (i.e. 19L stockpot) is all some brewers can afford, but this need not be an impediment to full- sized batches, nor with any additional risk to a brewer unsure if AG is for them. This is all explained in MaxiBIAB, BTW. It is horses for courses though, and I also think the situations are just too diverse to put a blanket over them all like that without some qualification. Consider sparging just another tool, say a tool as frequently used as a torque wrench for instance- just because most mechanical jobs don't need it doesn't translate to mechanics discarding them en masse, while many mechanics can get by fine without ever touching one.
What does bother me though is that many novice brewers looking to try BIAB for the first time seem to assume that a sparge is necessary, perhaps because most other AG methods have a sparge step, that's a PITA and has led many a conversation up the garden path.
:scratch:
Last edited by Ralph on 02 Nov 2010, 07:46, edited 5 times in total.
[center]Give me a beer and I will move the world. Archimedes[/center]

Post #3 made 15 years ago
by PistolPatch
I should do some side by sides on this hashie because there aren't really any good figures on all this. If your vessel isn't big enough to mash with all your liquor then it is no extra work to throw some hot liquor over the spent mash - sounds very sensible to me. If your kettle is big enough though, then the questions are, "How much, if any, is the increase in efficiency?" and, "Is the extra hassle worth it?"

I have two 70 L kettles and so am able to test both these things. For single batches my kettles are large enough to hold all the liquor but for double batches, I have to add in about 12 L at later stages. I have occasionally thrown some or all of this 12 L over the grain. I don't want to say what the results were as I would prefer to do side by sides and record the results over 4 or 5 brews before making any assumptions.

I have never sparged on my single batches but am willing to do 4 or 5 side by sides on this as well just out of curiousity.

So that's about 650 L of beer I need to brew before I can report back fully :roll:

My goodness!
PP
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Post #4 made 15 years ago
by hashie
We should have a reply by the weekend then Pat?

And what of the astringency myth. The myth that says if you use too fine a crush you will extract astringent flavours(?) from the ground husks?

I understand with 3v brewers they want their husks kept intact to help to create a grain bed for sparging. In BIAB we don't need a grain bed or a sparge for that matter. With a course or fine crush we all have husks in the liquor, surely if our beer was going to be astringent, it wouldn't matter if the husks were intact or torn, they are still in the liquor imparting whatever flavours husks impart.
"It's beer Jim, but not as we know it."

Post #5 made 15 years ago
by Ralph
Too right hashie, Pat we want this all done & dusted by Sunday at the latest! No ifs or buts, OK?!

Apropos astringency from the fine crush- Completely BUSTED!
[center]Give me a beer and I will move the world. Archimedes[/center]

Post #6 made 15 years ago
by hashie
My wife was drinking a cider last night and I noticed on the neck of the bottle, it read " Brewed longer at lower gravity for a naturally fuller flavour".

Now I know I am talking about cider not beer, but surely the results would be the same.

From my experience, leaving fermented wort on the yeast cake for an extra few days to a week makes for a cleaner beer. I would never describe it as having a "fuller flavour".

Have I got this all wrong, or is their statement a bit mis-leading?
Last edited by hashie on 09 Nov 2010, 05:14, edited 5 times in total.
"It's beer Jim, but not as we know it."

Post #7 made 15 years ago
by Ralph
OMG hashie! Don't tell me a marketer is fibbing! Right, that's it, I'm invoking the Spanish Inquisition... ;)

In all seriousness, I abhor vague, subjective terms such as those, they are meaningless fluff interspersed with technical- sounding terms disingenuously arranged to deceive and it automatically makes me wonder if there's nothing nice that can be said using objective terms. If that's the case I probably don't want to buy it.
[center]Give me a beer and I will move the world. Archimedes[/center]

Post #8 made 15 years ago
by hashie
I even asked my wife what she thought it meant.

Her answer was along the lines of "do they brew it under ground, so there is less gravity?"

My guess is that anyone not familiar with brewing would also think along some vague tangent.

Basically, the statement is vague, to say the least, and would mean absolutely nothing to the general public.
"It's beer Jim, but not as we know it."

Post #10 made 15 years ago
by SacSoul
Nerd spew to follow :geek: :
Image
Booo, image doesn't work. Here is the link: http://en.wikipedia.org/wiki/File:Gallic_acid.svg

This is the basic unit of tannins and will be rather water soluble. I'm guessing this has a pKa somewhere around 3 to 3.5, which would be the pH at which it would be the most insoluble (i.e. would have more trouble getting into water due to being in a neutral charge state). So, at normal brew pH (say 5 to 6) and with elivated temperatures, you will risk extracting this IF the water has access to it. The husk should be fairly hydrophobic and push water away, but if you shread it you increase the surface area (as has already been mentioned) and potentially increase the access the water has to the tannins. Now, keep in mind that tannins is a subclass of molecules that range in size a lot (http://en.wikipedia.org/wiki/Tannin) so the subunit will either be polymerized with itself of linked to other things. This will affect its pKa and it hydrophobicity (highly conjugated aromatic compounds will be less water soluble). That being said, elivated temperatures and acidic or alkaline water has the potential to break apart ester linkers, so the polymers or larger units could potentially break down at 155 °F to the shown subunit. Personally, I would try to not shread the husks if you wish to limit tannin extraction, but a side-by-side experiment is probably warrented to fully test this. I'm not nominating myself though... I don't have time for a side-by-side.
Last edited by SacSoul on 09 Nov 2010, 23:29, edited 5 times in total.
Arrogant Bastard Ale: "...Perhaps you think multi-million dollar ad campaigns make a beer taste better. Perhaps you're mouthing your words as you read this."
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