Homebrew Myths

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menschmaschine

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I thought it would be informative to have a thread dedicated to some of the myths still floating around out there regarding any aspect of homebrewing and the science behind the current points of view from reliable sources.

To keep the thread most organized here is a suggested format:

-Put a title on your post with the myth description. If you're responding to someone else's post/myth, leave the title line blank.

-State/describe the myth.

-Explain why it's a myth using science or current/widely accepted information.
 
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menschmaschine

menschmaschine

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Myth:
Many homebrew recipes and books indicate, when doing step mashes, to do a protein rest at ~122°F.

Response:
The purpose of a protein rest is to allow proteolytic enzymes (proteinase and peptidase) to breakdown various proteins down into smaller constituents. These enzymes are most active between 113°F (45°C) and 131°F (55°C).

In short, larger proteins cause haze (insoluble), mid-sized proteins cause foam/head retention, and small proteins don't do much of anything except add some body. Some of these proteins are inherent in the malt (barley type) and some are formed/broken down during malting. The more modified a malt is, the more these proteins are broken down. This is indicated (or calculated) on the malt analysis by the Kolbach Index or the Soluble Nitrogen Ratio.

In the "olden days", when malts were variably under-modified, if you wanted a haze-free beer, you needed to do a protein rest. Today's well-modified base malts have relatively high proportions of soluble proteins. Doing a protein rest can break these proteins down further so that the final beer is void of the mid-sized proteins you want for foam/head retention and malt flavor.

So, don't follow a recipe or book blindly when it comes to protein rests. Chances are you don't need it and doing one can reduce head retention and leave dull malt flavors. Your lowest rest temperature (unless doing an acid rest) should be in the mid 130s°F, but more likely the low 140s°F (and, subsequently, a rest in the upper 150s°F). Doing a rest in the low 140s°F can straddle the line between a protein rest and a saccharification rest. It will facilitate a small amount of proteolytic enzyme activity and break down a few large proteins to help with head retention while not breaking down too many mid-sized proteins to harm it.
 
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The myth:
One should always use liquid yeast over dry yeast.

The facts:
(from Mr Malty, Wyeast, White Labs, and several online supply stores)

A single 11g dry yeast packet, properly rehydrated, will result in a pitching rate of approximately 200 billion cells.

A single Wyeast Activator pack contains approximately 100 billion cells.

A single White Labs vial contains between 70 and 140 billion cells.

When making starters from vials or smack packs:
1 liter starter = about 150 billion cells
2 liter starter = about 200 billion cells
1 liter starter, then pitched into 4 liter starter = 400 billion cells

A five gallon batch of beer at an OG of 1.055 requires approximately 200 billion yeast cells for proper/healthy fermentation.

A properly prepared 2L liquid yeast starter is required to get the correct pitching rate for the aforementioned five gallon batch. Any error in procedure will decrease the cell count and/or introduce contaminants.

Many of the same strains are available in both dry and liquid form.

Dry yeast packets usually cost less than $2.

Liquid yeast vials/packs usually cost around $7, not including the cost of producing starter wort.

So, if the required strain is available in both dry and liquid form:
Choose dry yeast to minimize cost, minimize effort, and maximize pitching rate.
 

beerjunky828

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When you talk about using liquid yeast over dry yeast, are you just saying that proper fermentation will be carried out using dry yeast just as well and even better than liquid yeast?

From a personal standpoint, I have found the flavor of the beer that was fermented with liquid yeast is slightly better.

Have you noticed any flavor differences when you have used dry yeast over liquid yeast for the same recipe?
 
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Not only will the fermentation be just as healthy if not better, but the resulting flavor should be just as good if not better. I have experienced that with several recipes, including my pumpkin ale. In fact, my results using dry yeast have been so good that I avoid liquid yeast if at all possible.
 

Brewmasters Warehouse

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I will say that a little realized fact, IMHO, is that many commercial brewers use dry yeasts to ferment. Every type of dry yeast is available in kilo sized or larger bricks that are sold to breweries and brew pubs. I am not saying that every commercial brewery uses dry yeast exclusively, but many use dry yeast quite often.
 

SpanishCastleAle

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See...I wanted to post that protein rests sort of get a bad rep these days and that a short one isn't always bad (and I'm not even talking about haze at all). But I certainly can't 'out-science' menschmachine. I just find that I sometimes like the 'body/mouthfeel' better and don't notice any head retention problems as long as it's short...in very unscientific tests.
 

GilaMinumBeer

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Myth:
Many homebrew recipes and books indicate, when doing step mashes, to do a protein rest at ~122°F.
From my readings in the opinionated texts, there is still much debate on this.

Some authors stiull suggest that even a short 10 minute rest at the range you've cited is good at breaking down those haze forming proteins without a sacrifice to head retention or body. Some others even suggest that such a practice improves the "malt character" of the beer akin to that of a decoction.

Now, I would go not that far (to relate the maltiness to deco) but, I do routinely employ a protein rest for most anything but Pale Ales. 10 minutes at 120 and my beer is crystal clear in record time, I have less to no need for IM. And I still maintain a huge malt backbone and a head that takes days to recede.

So, I agree and disagree. I think the amount of time spent at said rest range is more detrimental than the act of the rest alone. For well modified malts I use no more than 15 minutes. I treat the rest as a "smoke break" on the way to the "buffet".
 
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menschmaschine

menschmaschine

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From my readings in the opinionated texts, there is still much debate on this.

Some authors stiull suggest that even a short 10 minute rest at the range you've cited is good at breaking down those haze forming proteins without a sacrifice to head retention or body. Some others even suggest that such a practice improves the "malt character" of the beer akin to that of a decoction.

Now, I would go that far but, I do routinely employ a protein rest for most anything but Pale Ales. 10 minutes at 120 and my beer is crystal clear in record time, I have less to no need for IM. And I still maintain a huge malt backbone and a head that takes days to recede.

So, I agree and disagree. I think the amount of time spent at said rest range is more detrimental than the act of the rest alone. For well modified malts I use no more than 15 minutes. I treat the rest as a "smoke break" on the way to the "buffet".
Yes, I agree with you. There is a debate as to whether a short protein rest in the traditional temperature range is similar in benefit to a standard-duration rest in a higher protein-related temperature range. I've not tried the short duration, traditional temp. protein rests, so it's good to have your input. I've only seen the difference in standard-duration rests at the lower and higher temp. ranges and the head retention was significantly better in the higher temp ranges (same base malt).

One thing to consider is when doing decoctions, it would probably not be possible to do a short duration protein rest simply due to the time involved with decocting.

I guess the bottom line is, learn about your malt and make an educated decision for your protein-related rest temperatures and durations.
 

GilaMinumBeer

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To this I agree completely. There were only 2 reasons why I began to dabble in the afformentioned rest range.

The first was newly acquired ability. I got a RIMS job and now had infinitely better control over my mash schedule.

And the second was persistent chill haze with certain malts. Usually, Brewers 2 Row.

After a few mistakes, and a lot of reading. I stumbled into the short rest practice and my beers have thanked me ever since.
 

Boerderij_Kabouter

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I use a 10 minute protein rest at 122º F and have good anecdotal results. My American wheat had the most ridiculous head retention I have brewed so far. Think La Chouffe kind of head.

I have the ability to quickly ramp temps though. After some reading I agree that a long protein rest at these temps can only hurt with our highly modified malts.

Mensch, what is different about the 133º range?
 
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menschmaschine

menschmaschine

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Mensch, what is different about the 133º range?
I think it comes down to proteolytic enzyme activity. Enzymes have an optimum temperature range, but they don't necessarily stop working outside that range.

So, going above that optimal range will have limited proteolytic enzyme activity, but not too little, like in a saccharification temperature range.

This is why I will concede that the short duration rest in the optimum range could be just as beneficial... because it's the same concept in limiting enzyme activity. But this could be dependent on your brewhouse. If you use hot water infusions to raise temperature, the temperature comes up quickly. But if you direct heat your step temps, starting at ~120°F and going up to saccharification rest ~150°F leaves a good additional 10-15 minutes where there could still be further proteolytic enzyme activity as it moves up through the 120s and 130s°F.

I've also seen discussion that different temps in the proteolytic range are better for breaking down specific sizes of proteins, but I don't believe there is conclusive evidence of this.
 
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menschmaschine

menschmaschine

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So, if the required strain is available in both dry and liquid form:
Choose dry yeast to minimize cost, minimize effort, and maximize pitching rate.
I whole-heartedly agree with this. However, I would emphasize the first part of that statement. There are certain liquid yeast strains that have unique flavor profiles that aren't currently found in dry yeast strains. So, if I have used a liquid yeast in a recipe that I'm very happy with and this strain isn't available in dry form, I wouldn't substitute a dry yeast for it. I have also noticed a certain level of refinement (in flavor) in the liquid yeasts I've used compared to dry yeasts.

But Yuri is totally right. If a yeast strain you want is available in dry form, it only makes sense to use the dry yeast. Lagers are my big issue. The starters are an even bigger PITA than ales and I've read about too many flavor issues with most of the dry lager strains, so I haven't ventured to use them... until recently.

I made a German Pils 2 weeks ago with Saflager W34/70 which is supposed to be the same strain as WLP830 and Wyeast 2124. So, in a couple months when it's ready to drink, I'll post my results. If it's as good as WLP830, goodbye lager starters.
 

SpanishCastleAle

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I've also seen discussion that different temps in the proteolytic range are better for breaking down specific sizes of proteins, but I don't believe there is conclusive evidence of this.
I've had better luck with short 122 F rests than I have similar duration 133 F rests...but a very small sample size there. I've only done a few 133 F protein rests. And again...I don't do it for clarity...rather for flavor (mainly body/mouthfeel).

I have one beer that I (mistakenly though I didn't know it at the time) let rest at 122 F while I did a decoction w/ 45 minute boil. That beer is a lager...and has more chill haze than any other lager I've done. Maybe the proteins got broken down so much that the polyphenols had nothing to bond to? Or at least not enough to make the whole clump big enough to sink?
 
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menschmaschine

menschmaschine

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I have one beer that I (mistakenly though I didn't know it at the time) let rest at 122 F while I did a decoction w/ 45 minute boil. That beer is a lager...and has more chill haze than any other lager I've done. Maybe the proteins got broken down so much that the polyphenols had nothing to bond to? Or at least not enough to make the whole clump big enough to sink?
That's very interesting. That backs up the hypothesis that higher protein-related temperatures are better for breaking down larger-sized proteins. In your case, they didn't get broken down. How was the foam stability, body and mouthfeel?
 

SpanishCastleAle

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Head retention is poor. Mouthfeel is also poor but I think I extracted excessive tannins in this beer so that prob skews the mouthfeel and also prob contributes to the haze. Maybe it was just too many polyphenols to begin with. This brew was subpar in more ways than one, it's far better than BMC just not one of my better efforts.:(
 

z987k

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I guess the bottom line is, learn about your malt and make an educated decision for your protein-related rest temperatures and durations.
I think this is the most important thing here, aside from yuri's comment. I use a high amount of under or even unmodified malt in some of my beers. They get a good protein rest. 50% unmalted wheat.... yeah.

As far as myths go, and I really don't know why I have to explain this, but using ale yeast or any kind and calling it a lager because the grain bill was for some lager you were wanting to make, does not make it a lager. It is an ale and it will NOT taste like a lager.

Esters do not belong in a bock.
Esters do not belong in anything scottish or irish and a handful of other beers.
Diacetly is usually inappropriate.

I always thought those were rather self evident, but in tasting a lot of homebrewed beers lately.. and some brewpubs, I think some people forgot about the basics.
 

jkarp

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I just know if my grist has rye, wheat, or oats and I skip the protein rest, I end up loosing 5-10 points efficiency due to slow sparge. A 10-15 minute 122F rest makes all the difference on my system with un-malted grain.
 
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