Fining then Repitching Seems Counterintuitive

[bmurph]

I've been looking into using gelatin as a fining agent for an ale I just brewed, and many who do this say they also pitch more yeast into the bottling bucket before bottling. I want a crystal clear beer with good carbonation but this practice seems to work against itself.

What's the point of clearing up the beer if I'm just going to make it hazy again?

Or does lack of O2 and presence of ethanol keep them from multiplying high enough to cloud the beer?

I haven't repitched with any of my beers, and it's not that they come out flat- they are bubbly- but they usually pour almost no head, what little head that forms is gone in less than a minute, and I never see lace on the glass. Would repitching enhance the beer's head?
Also, a professor I get brewing info from says that regardless of the beer style- ale or lager- he always uses lager yeast and holds the bottles at room temperature to carb his brews...is there merit to this practice?

 

[Nateo]

If your primary yeast is a poor flocc'er, then you could cold-crash and add finings to clear it up. I would then pitch another yeast that was a good flocc'er to carb with.

If your primary yeast is a moderate/good flocc'er, then you should be able to get crystal clear beer without doing anything extra, assuming that your brewing process up to that point was solid. Yeast are only one factor that will haze your beer.

As for the head issue, that could be a number of things. You want the proteins to be soluble. I would say the way you're mashing is the primary culprit for both the haze and the poor head retention.

 

[GilaMinumBeer]

Gelatin is not considered an effective yeast fining agent. IIRC it has to do with the Gram Negative charge of the molecules being the same as yeast.

It is however a good fining for protein.

 

[bmurph]

If your primary yeast is a moderate/good flocc'er, then you should be able to get crystal clear beer without doing anything extra, assuming that your brewing process up to that point was solid. Yeast are only one factor that will haze your beer.

This yeast has reportedly high flocculation, but I did dry hop this beer so I'm guessing the fining is necessary. And how much extra yeast is enough to carb the beer?
Any thoughts about the lager vs ale yeast?

 

[smokinghole]

The reason for some fining is the haze causing proteins and not necessarily yeast.

 

[greenbirds]

I will propose a two-pronged answer to your first question. Gelatin fining may or may not drop much of the yeast, clearing the beer in the process. There might be enough left in suspension to carbonate the beer in a timely manner. But if a brewer adds more, I guess it would be so that he or she can do so in a controlled fashion, so that the bare minimum is added, reducing the amount of sediment in the bottles.

Gelatin fining will also drop out some polyphenols (tannins) that can bind up with proteins and cause chill haze.

Your foam/head problem sounds like it is due to dirty glassware. Even if it looks clean, there is probably an invisible residue that is killing the foam when you pour. Fresh, all-grain, adjunct-free beer is very difficult to keep from lacing in a beer clean glass, regardless of style or ingredients, unless the mash was screwed up.

I'm not sure about priming ales with lager yeast. I cannot really see the benefits this practice would yield. If anything it seems like a negative, as lager yeast at room temp could produce some (albeit small amounts of) funky flavors. Also, lager yeast can metabolize some polysaccharides that ale yeast can't, which seemingly could lead to overcarb issues... But that's just speculation on my part.

 

[greenbirds]

Gelatin is not considered an effective yeast fining agent. IIRC it has to do with the Gram Negative charge of the molecules being the same as yeast.

I don't know about this. From what I have read, various yeast strains react differently to gelatin or isinglass (collagen, a protein itself, is the common agent here) fining, depending on how negatively charged they are. It was probably a typo, but gram negative has nothing to do with the discussion as it refers to bacterial cell wall composition, not yeast.

It is my experience that gelatin really helps to drop Cali ale (WLP001/S-05) yeast.

 

[bmurph]

if a brewer adds more, I guess it would be so that he or she can do so in a controlled fashion, so that the bare minimum is added, reducing the amount of sediment in the bottles.

Your foam/head problem sounds like it is due to dirty glassware. Even if it looks clean, there is probably an invisible residue that is killing the foam when you pour. Fresh, all-grain, adjunct-free beer is very difficult to keep from lacing in a beer clean glass, regardless of style or ingredients, unless the mash was screwed up.

What is the "bare minimum?"

Also, my past brews have been either all extract or partial mash, but this one I'm about to bottle is my first all grain batch, so should I be expecting some better head retention just because of that?

 

[GilaMinumBeer]

I don't know about this. From what I have read, various yeast strains react differently to gelatin or isinglass (collagen, a protein itself, is the common agent here) fining, depending on how negatively charged they are. It was probably a typo, but gram negative has nothing to do with the discussion as it refers to bacterial cell wall composition, not yeast.

It is my experience that gelatin really helps to drop Cali ale (WLP001/S-05) yeast.

Not a microbiologist but it was my understanding that yeast does have some bacterial growths on the cell membrane taht do register it as Gram Negative and effect the electro-magnetic properties of it's attraction/repulsion from Gelatin.

My further understanding is that the level of purity in the collagen that makes up gelatin is substandard compared to that of Isinglass which is what deems gelatin as a poor fining for yeast.

 

[greenbirds]

Apologies for taking this further off-topic. You are correct that Saccharomyces will gram stain (apparently spores will stain negative and cells positive), but it's not due to bacterial growths or anything like that. Yeast cell walls do not contain peptidoglycan, which is what gets colored during a bacterial Gram stain. From what I understand they stain due to the sheer amount of material absorbing the dye.

I couldn't find any information to support the notion that gram stain status is related to charge or electromagnetic properties.

Yes, isinglass is a purer source of collagen than gelatin. How much purer I don't know, as I can't find any quantitative figures, but that is generally recognized as true.

 

[bmurph]

I was planning on picking up some gelatin from the grocery store...but where could I find isinglass if I wanted to use that?

 

[BioBeing]

I couldn't find any information to support the notion that gram stain status is related to charge or electromagnetic properties.

That's because it isn't.

http://en.wikipedia.org/wiki/Gram_staining

 

[GilaMinumBeer]

I couldn't find any information to support the notion that gram stain status is related to charge or electromagnetic properties.

That's because it isn't.

http://en.wikipedia.org/wiki/Gram_staining

Well, bless me, somehow I was under the impression that Gram staining also gave an indication to electrostatic state of the microbe (perhaps by way of makeup). My mistake. My apologies.