Monday, February 29, 2016

How to make a Session IPA clone... spring and summer are coming!

Yes, I know... alright.  You don't have to tell me... session beers have become all the rage. Every micro pub and brewery has them now.  But I was brewing sessions before they had a cool name.  Not because I was some trailblazer, I wasn't,  but rather because that is what we brewed in the dark ages.  In the early years of home brewing we didn't have all of the computer software, and technology we have now.   Most of the recipes we brewed were between 1.040 and 1.050 original gravity.   Because... well that's just how it was.   No one had thought of a double IPA in 1992.   So we made lots of American Pale Ales, and English IPAs.    Sure, when we made a Russian Imperial Stout, or an Imperial Porter we bumped that gravity up as high as we could but we only brewed  those maybe once a year.

Why?, you ask?   Well the main reason is that the beer culture in America was centered around light american lagers that were all 3.2% alcohol.  So making a 4-5% alcohol beer was comparatively strong.  But I think the quality of the yeast, and what we knew about yeast had a factor in our brewing too.

So we brewed a lot of lower alcohol beers.  Beers we now call Session Beers.   When you think about it, session beer makes a lot of sense.   With a session beer you can enjoy multiple beers with out becoming intoxicated.   Intoxication and alcoholism are real problems.  We often make lite of them in our hobby, but I believe that if we were being real and honest we would all admit that drinking too much is a problem among some home brewers.  (And if you do choose to get drunk, do it at home and never ever freaking drive drunk!)  But session beers offer more than the ability to have multiple beers . Session beers are fun.  It is fun to try to make a beer reminiscent of one of your favorite high alcohol beers. It requires thought, planning and creative experimentation.  And finally session beers cost less than high OG beers.  They just do, less grain, less extract, less yeast always equals less cost.

So with those things in mind I am going to give you some tips to cloning the big beers you love into reminiscent session beers.  These are not true clones.  They are homages to their bigger inspirations. Today I present to you Pliny the Petulant.  A less than 5% alcohol version of a great IPA.   I'm sure most of you have heard of Pliny the Elder and Pliny the Younger.   Some of you may have even heard of Pliny the Toddler.   For those of you who haven't,  "Pliny" is a beer by Russian River Brewing.  It is debatably the penultimate imperial India pale ale.  I'll let you research and try for your self.

I have a long love affair with this beer.  It is with out question one of my 2 favorite dIPAs (the other being Boulevard The Calling, which I don't think lends itself well to a session approach).  So when I set out to make a session IPA for spring and summer... I'm setting out to make a version of Pliny.   I'm setting out to capture the flavor profile of this beast.   Having said that I am not the first,  Drew Beechum's recipe for "Pliny the Toddler" is widely available online.  As is the recipe from The Maltose Falcons brew club.  I have made these recipes many, many times.  I have even blogged about them several times. They are great recipes.  But I have brewed them and made certain tweaks over time.  Tweaks that have gotten me exactly what I want.

In Planning a session, There are two approaches.   The first approach is to try to capture the flavor profiles of the original beer with out worrying about the balance of IBU to OG.  When you take this approach, and I certainly prefer this approach and have taken it many times,  you aren't as worried about the ratios and % of the hops, or the balance index?   Wait, you did it again, you used some term no one has ever heard...  You're right I did.   The balance index is merely the IBUs / OG.  In Pliny the real laboratory IBUs are insanely high... approaching 250.  But the perceived IBUs are around 95.    And this is the gist of the other approach.  Leave the % of hops the same,  and leave the balance index the same. make a smaller beer with exact percentages.  I have done this too and... I think the first approach is actually the better one.  But with either approach we still have to do some math and some planning and we have to look at the original recipe carefully.   So here is the American Home brewers Association published clone recipe for Pliny the Elder.  

6 Gallons (22.7 L) 5.5 to the second fermenter
75% efficiency
OG 1.072
FG  1.011
IBUs  90 -  95 (200)
Balance Index - 1.319
ABV is around 8%

13.25# of 2 Row Barley
.6 # of Crystal 40
.6 # of CaraPils
.75# of Corn Sugar (late boil)
3.528.00%oz (99 g) Columbus* hops, 13.9% a.a. (90 min)
0.756.00%oz (21 g) Columbus* hops, 13.9% a.a. (45 min)
18.00%oz (28 g) Simcoe hops, 12.3% a.a. (30 min)
18.00%oz (28 g) Centennial hops, 8% a.a. (0 min)
2.520.00%oz (71 g) Simcoe hops, 12.3% a.a. (0 min)
18.00%oz (28 g) Columbus* hops, 13.9% a.a. (dry hop, 12-14 days total)
18.00%oz (28 g) Centennial hops, 9.1% a.a. (dry hop, 12-14 days total)
18.00%oz (28 g) Simcoe hops, 12.3% a.a. (dry hop, 12-14 days total)
0.252.00%oz (7 g) Columbus* hops, 13.9% a.a. (dry hop, 5 days to go in dry hop)
0.252.00%oz (7 g) Centennial hops, 9.1% a.a. (dry hop, 5 days to go in dry hop)
0.252.00%oz (7 g) Simcoe hops, 12.3% a.a. (dry hop, 5 days to go in dry hop)
West coast ale yeast (WLP 001, Wyeast 1056, Safale US05)  appropriate starter.
1 tsp Whirlflock at 15 M
1 tsp Yeast Nutrient at 12 M
Ferment at 67 F till fermentation subsides.
Rack to secondary.   Yes actually rack it, there are loads of dry hops in this beast.
Dry Hop in secondary, again you'll thank me... you'll lose way less beer with secondary in this particular recipe.
Let it finish, and package it!

So A little math and planning tells us that we want a recipe that looks something like this...

6 Gallons (22.7 L) 5.25 to the fermenter
75% efficiency
OG 1.045
FG  1.007
IBUs  50 to 55
Balance Index - 1.319

The goal is creating a beer that captures the beer being cloned.   It's that easy to "sessionize" your favorite big beers.   Of course you'll have to brew it, drink it all, and tweak it a couple of times.   I've done that bit for you... you're welcome!   But if you do you'll end up with something that looks like this...

Pliny the Petulant

Method: All Grain 
Style: American IPA
Boil Time: 60 min 
Batch Size: 5.5 gallons (fermentor volume)
Boil Size: 7.5 gallons 
Boil Gravity: 1.033 (recipe based estimate) 
Efficiency: 75% (brew house)
Source: Counterbrew 






AmountFermentablePPG°LBill %
7.6 lbAmerican - Pale 2-Row371.888.4%
0.5 lbGerman - Caramel Pils352.45.8%
0.5 lbCorn Sugar - Dextrose460.55.8%
8.6 lbTotal

0.3 ozWarriorPellet16First Wort11.71
0.5 ozColumbusPellet15Boil45 min27.73
0.5 ozSimcoeLeaf/Whole12.7Boil30 min17.87
0.25 ozCentennialLeaf/Whole10Whirlpool at 180 °F0 min
0.5 ozSimcoeLeaf/Whole12.7Whirlpool at 180 °F0 min
0.25 ozCascadeLeaf/Whole7Dry Hop4 days
0.25 ozCentennialLeaf/Whole10Dry Hop4 days
0.25 ozSimcoeLeaf/Whole12.7Dry Hop4 days
Hops Summary
0.25 ozCascadeLeaf/Whole7
0.5 ozCentennialLeaf/Whole10
0.5 ozColumbusPellet15
1.25 ozSimcoeLeaf/Whole12.7
0.3 ozWarriorPellet16
Mash Guidelines
8.72 galNo sparge brew in a bagTemperature150 F60 min
Starting Mash Thickness: 4.36 qt/lb
Attenuation (avg):
Optimum Temp:
54 - 77 °F
Fermentation Temp:
67 °F
Pitch Rate:
0.75 (M cells / ml / ° P)
175 B cells required

This is what we'll be brewing this coming weekend.  And to make things even easier, we will be doing a no sparge batch.   We put all but 1 gallon of the water into the mash tun and all of the grains. If our temp is spot on we add the withheld 1 gallon when it is at the mash temp.  if we are too high we add up to 1 gallon of cold water until we are at temp.  Were almost never too low, but if we were we could add up to 1 gallon of 170 F. water to get to temp.  This is the easiest way to brew by far.   We use a bag as a filter medium, but you don't have to if you prefer a false bottom or stainless supply screen. After 60 minutes we stir, check our gravity, and usually we are ready to drain into the kettle.   Yes I know some of you are  freaking out right now  what about pH, what about ideal mash thickness, what about, what about... Kai says... John Palmer says.... Just adjust your water, use good buffers, and give it a try it works just fine. (OK clearly I've touched a nerve with a disciple of the BrauKaiser who has chosen to PM me rather than post publicly,  Listen, I am a huge fan, nearly a devotee of Braukaiser... but no sparge works every stinkin time, so just try it!)

From there on it is just like any other batch... It is really that straight forward.    With No sparge brewing you can reduce your brew day to under 3.5 hours if you are organized and plan in advance.  

That's all for now sports fans.  Prost!

Sunday, February 28, 2016

C4 Hop Explosion...American Pale Ale Hop Bursting Action Inside!

John came up with the perfect name for the APA that
features 4 "C" hops!
Pale Ale.  Good ol' pale ale.  The impetus of the craft brew revolution.  The craft brew that started it all, the craft brew that the muggles will actually drink.    I think we all love pale ale.  But you have to admit that pale ale has become a bit ordinary.  A bit too familiar.  So we here at counterbrew, your ever faithful servants, are here to update the common pale ale into the hop explosion that it can, and maybe should be.

Pale ale is an awesome background malt bill for hops.   The maltier wort and ever so slight roasty flavors create an interesting backdrop when balanced against the hops.   But beware, this is not the right background for 70-100 ibu IPA hops.   This is the right back ground for the "c" hops.   You remember the C hops.  Chinook, Cascade, Centennial, Citra. (and sometimes Columbus).

Before 5star pH stabilizer pH was 8.1
Due in part to the camden addition the night before.
So Saturday we set out to brew an American Pale Ale.  A "hop explosion" ,  But not an unbelievably bitter beer. A Beer with loads of late hop additions.   We were brewing 10 gallons.  But of course there was a problem with the keggle so we had to split the batch into 2 separate boils.    It was time for the counterbrew crew to understand why we are so committed to BIAB, and no sparge brewing.  So to aid in that understanding, and also because I get a maniacal pleasure out of it.    We did our first 3 vessel brewing session as a group.  John prepared the water the night before with camden.  If you're not using camden to knock the chorides out of your water, then you need to start.   John and Jake had the water heating when I arrived, and we did a simple water treatment.    We added 1 TBLSPN of 5.2 stabilizer for each 5 gallons.   For those of you who don't like 5 Star 5.2 pH stabilizer... get over it.
After 5 star 5.2 stabilizer the pH was 5.86
There has been an unsubstantiated trend on forums recently.  This trend is to say 5.2 stabilizer doesn't work.  Or 5 .2 makes beer salty (whoa there Poindexter, it's not even that kind of salt).   There is no science behind this trend, just a bunch of guys who feel like they are better brewers if they do things the hard way.   Here is a fact from brew day.   By the way, don't you dig Johns zooba shorts (KC Chiefs ) and black socks.

  • pH after camden and before 5.2 =  8.1
  • pH after 5 star pH stabilizer = 5.86
  • pH of the mash was... pause for dramatic effect... 5.2. Right on the money!

All hands on deck for the dough in.  Mark Anthony and his brother Rob
Helped us get doughed in!  3 spoons makes quick work of dough in!
We put 21 lbs of grain into the mash tun, in a bag.  And we hit it with 167 F water.  Stirred to prevent dough balls and that was it.  Our initial temperature was a little high so we stirred.  Missing your initial temperature can lower your efficiency, and it did a little bit. (We only got 72.86% hoping for 75%  We could have added .25lbs of sugar or DME but we just rolled with it! ) We got it to 152 and let it sit for 90 minutes.  Then we drained it off and batch sparged.   We let our batch sparge for 15 minutes.  

spilit the boil
in the future the
keggle will rock!
Today we had to boil in 2 separate pots.  The keggel needs some new parts, a new high pressure hose, a new regulator, and a new 3/8th" flared orifice.   But soon, very soon we will be brewing with 150000 BTUs of banjo burner power again.  I for one cant wait.  This brew day was 5 hours long.  My crew now understand how long a 3 vessel brew day can take.  They now also understand the pros and cons of 3 vessel.  There are times when not having to mess with and monitor the temperature of your mash is a benefit.   A brew day where you need to bottle and do other brew house chores, for example.

Now, here comes the fun part.  The part you have all been waiting for... the hop schedule ( really the whole recipe).
Jake handling the hop bursting!
Bursting may be the trick you
are looking for!

C4 Hop Explosion Pale Ale
OG 1.052
FG  1.008
SRM 11
ABV 5.9%
Taste  - Citrus and lemon notes, with cedar, pine, floral, pepper, and green mellon.   freaking awesome!

16.5 lbs of pale ale malt (ask for RAHR PALE ALE)
2.5 lbs of biscuit malt
.75 lbs of caramel/crystal 80
.25 lbs of caramel/crystal 20
Mash at 152 for 90 minutes.
Sparge to volume
1 tsp of gypsum added mid boil
1.5  ounces of Chinook @ 60
1.5  ounces of Centennial @ 15
1.5  ounces of Cascade @  10
1.5 ounces of Citra @ 10
2    ounces of Centennial @ 5
2   ounces of Cascade added to the whirlpool at 190 to 180 degrees (hop bursting)
2   ounces of Citra added to the whirlpool at 190 to 180 degrees
2   ounces of Cascade dry hop for 4 to 5 days
2   ounces of Citra dry hop for 4 to 5 days
US 05 (2 packs) rehydrated in 1.035 wort during our brew day!

Jake setting the chamber to
64 F.  Yes, he is freakishly tall!
Chill to 185 F.  Then add the whirlpool hops, allow them to burst for 10 to 15 minutes then continue with the chill.   By the way sanitized silicone gloves are a great way to get all that hoppy goodness in your beer, if you, like us put your hops in a bag.

We are fermenting in temperature controlled fermentation chamber at 64 F.  So with endothermic heat the batch should rise to about 68 F.  Which is right where we want it.  With US05  if you ferment at 68F you will get very slight fruity esters.  They should compliment the beer perfectly.  If you ferment cooler, there are very few esters at all.  Its not as clean as K-97 but it is really clean.  Jake set the temp to 64 and now we wait.

But our wait wont be too long.  It's only a 1.050 beer.  The US 05 will chew through this batch in no time.   Should be adding dry hops in 10 days and packaging the beer in about 14 days.


Tuesday night John reports fermentation was slowing down.   He turned the chamber temperature up to 66 F to help the yeast finish strong.  In about a week he will dry hop for a couple of days, fine with gelatin and cold crash.   This one should be ready after just 2 weeks.   We'll bottle and be ready to drink in another week.  Cant Wait.

Thursday, February 25, 2016

The future of home brewing... Its in the bag!

You can get as complicated as you want!
If that is fun for you, go for it!
I prefer to keep it simple!
If recent days have taught us anything, they have taught us that we live in a world that is changing faster than any of us could have ever imagined.   Facebook and Twitter are a part of our everyday lives, they weren't even around 10 years ago.  (Well ok, they were around but not like they are today) And 10 years ago no one had ever even heard of eBIAB RIMS (or HERMS).  I'm sure they existed but very few home brewers were using them.

yes, I am that nerd who enjoys
a tripple decoction brew day!
Now it seems like everyone is building some behemoth system capable of cranking out home brew with the push of a button.   Bluetooth compatible, iPad controlled wort machines may be all the rage.  But I take a different tact. First of all, I don't really want push button beer.  I enjoy controlling the process.  I like the contact with my beer.  I imagine myself a wort whisperer.  I want to be the one to stir my mash and check it's temperature. I taste the mash.  Heck, I even enjoy decoction mashing. ( the SWMBO has a retreat coming up and I fully intend to fully nerd out and triple decoct a Vienna lager) I want to write it down in our brewing log, not have it automatically upload to google cloud. And I want everything to be simple and easy to clean.  (you cant clean what you can't see, and minor infections ruin good beer).

I know (not suspect KNOW) after 25 years that it is the brewer, not the equipment! I have tasted world class beer made on ghetto brewing systems! I will state quite arrogantly, I make far better beer than I can buy.  And for the most part far better beer than I have at club, or the LHBS.  (if you want to try my beer, come brew with us when you're in're always welcome and KC is a blast!)   I think part of the reason our beer (my beer) is so excellent is that we are in touch with our process.  So I try to keep everything old school.     So I avoid most of the new fangled technology up grades.   But there is one improvement I do not shy away from;

I think the most significant improvement in brewing, since I started brewing 25 years ago... it the Brew Bag. (the quality of malt extract being a close second)  

Affordable brew bags!
I use a brew bag for lautering my grains no matter what system I am using.   And as I have said numerous times.  I have several systems.  This weekend, we will be breaking out the 10 Gallon, 3 Vessel system.  We need to get ready for summer, and that means we need to get some 10 gallon batches of August Hyppo Pale ale, and Johns Cream Ale ready.  I don't often post about large brew days on the blog.  This blog targets newer, and intermediate brewers.  But we do brew some more advanced stuff, some sours, some decotions, and some large batches.  Saturday, I'll let you all behind the veil at counterbrew studio 2 (John's house)  But even when I use the ol' system, which I am admittedly somewhat romantic about.  I wont be doing it with out a brewing bag.   Brewing Bags offer home brewers many advantages.

  • Higher efficiency due to finer crush.   
    • yes I know some of you don't believe this, but it is true, try it for your self, this is a well established fact of home brewing now. 
  • faster vourlauf - sometimes no vourlauf 
    • you don't know till you give it a try, usually I pull about 1/2 of a quart and were done. 
    • Can you brew a 100% wheat or rye beer?   I can.  
    • Can you brew a pre prohibition pilsner with 65% corn & rice and 35% pilsner?  I can.
  • Faster brew day
  • Higher efficiency

Zapap Lauter tun still works
one bucket with holes drilled
inside of another bucket!
So, I don't understand why some guys will spend hundred and hundreds of dollars on an amazing false bottom, but wont spend $40 on a brew bag?   I have used bags from both of the major suppliers, they both worked fine.   They're both just tools for lautering.  When I started brewing we had separate lautering buckets.    We wold mash in a great big pot, then transfer the mash (grain and all) to a lautering tun (2 plastic buckets 6.5g and 5g).   The zappap lautering tun.  Still works.  But there are some of you that think the zappap is real brewing, and the use of a bag is sacrilege.  And folks that makes as much sense as mustard on a birthday cake! 

the overwhelming best advice I ever got
Keep it simple!  Learn your system!  Become a wort whisperer
and always remember "brewers make wort, yeast makes beer"
It's all about coaxing flavors out of the grains, and creating the
right environment for the yeast!
A brew bag is no different than any other filter you use for lautering... except... they work better.  What ever drunk aussie thought of the brew bag... should get a medal and free beer for life!  They make everything faster.   "if they're so great why aren't commercial breweries using them".   My answer;  They are, or at least they are trying to replicate them.  I have it on excellent authority from a brewer at a major label that they are trying to add a permanent filtering medium to their experimental brew house.   Inspired by BIAB efficiency, they are working with an engineering firm trying to create filters inspired by this home brewing process.  And why the hell wouldn't they? Increased efficiency = increased profits.   And further who cares what they do?  We are home brewers, we have certain advantages over the big boys.  This is one of them.   So no matter how you brew, I suggest strongly that you work a brew bag into your system.   You won't regret it!

Here is my trusty ol mash tun, and keggle set up,  150,000 BTUs it can easily handle no sparge 5 gallon batches, and can easily handle traditional 10 gallon batches of beer.
My keggle was purchased legally
from a distributor.  It features
a 150000 BTU banjo burner!

I removed the pvc false bottom
from my ol mash tun, and now
use a bag.  The bag was sewn by a friend.
She charged me a beer, The fabric cost
me $9.00
And here it is in action.

Wednesday, February 24, 2016

THE ACTUAL TRUTH ABOUT YEAST: Volume 2 Ale Yeast with Kevin Lane of Fermentis

Today we continue our series with Kevin Lane of Fermentis, and we are focused on Ale yeast.   We will be taking a basic look at Ale yeast biology, understanding some of the terms you hear associated with ale yeast, and talking about how to get the flavors you want from ale yeast.  Any thing in italics I added, or clarified.  

We will gain an understanding that temperature, pH, pitch rate, and wort composition are tools you can use to make the beer you want.  And this is a very important point.  Too often now on home brewing forums I hear guys espousing "rules" ... "you have to do this"  or "you must do that"   To me, it is clear that these guys do not want to understand, they want to follow a set of rules that will make them successful.  Unfortunately, true success requires understanding.   My old mentor used to say "Recipes are for people who can't, or wont understand"  I finally get what he meant.  He would check gravities during the mash, and add base grain.  He would check color against a chart and cap his mash with crystal grains.  He would even check pH and see if it was optimum for the fermentation phase.  All because he understood the process and enough of the microbiology to make the adjustments. 

Yes this is a long post,  but read it. 
This is the stuff you actually need to know!

And always remember,  Brewers make wort, yeast makes beer!

What is ale yeast?  What makes it different from lager yeast?

Ale yeast is defined as top fermenting yeast.  Ale yeast (saccharomyces cerevisiae)  is a different species from lager yeast (saccharomyces carlsbergensis (former} orpastorianus {current}). Ale yeast, also prefers to ferment at warmer (usually ambient) temperatures, whereas lager yeast prefers to ferment at cooler temperatures.  The yeasts don’t actually prefer one over the other, they just produce better flavors/aromas and may ferment “better” in human terms.  Ale yeast, additionally, has a much larger variety of flavor and aroma production, as lager yeast has been selected by humans for centuries and has been (intentionally)  limited in the genetic differences.  There are a large number of different ale yeasts available in the market: American, English, German, Belgian, French, etc.

So top cropping versus bottom cropping? (Taking yeast from active fermentation)

When you choose whether to top crop or bottom crop, you are selecting different phenotypes (genetic differences).  If you top crop, you will be selecting the yeast that is more likely to form branched groups of cells that get stuck in the krausen during fermentation.  Traditionally, German ales have been top cropped for many styles, but the most common is hefeweizens.  If you were to top crop and bottom crop from the same batch of beer (separately) and repitch into the next batch (separately), you would likely see a difference in flavor/aroma production.

Why can ale yeast perform at higher temperatures?

Ale yeast performs better at higher temperatures.  That isn’t to say that you can’t use lager yeast at higher temperatures (ex. W-34/70 at warmer temperatures); you can, there is just higher potential for off flavor development (sulfurs, meaty notes, cider type flavors, etc).  Ale yeast are and have been naturally occurring yeast strains in regions that have warmer typical temperatures.  There are different stories about lager yeast and where that genus species came from, but my understanding is that lager yeast is a decedent from a cross between wine yeast (beyanus) and ale brewing yeast.  Wines are typically produced in coastal regions where the overnight temperatures drop to a fairly cool temperature with moderate humidity, so I could understand how lager yeasts could be a decedent of saccharomyces beyanus (wine yeast). Wine is also typically fermented at cooler temperatures when compared to ale yeast, so the cross between the two species is understandable: the maltose and maltotriose fermentation coming from the cerevisiae and the affinity for cooler temperatures from beyanus.

Back to the question, ale yeast performs better at higher temperature because that is how the environment was that the yeast came from.  Again, it’s not to say that ale yeasts definitely can’t ferment at cooler temperatures, they can, just might be slower and produce more neutral beer (ex. K-97 at cooler temperatures).

What impact, in general, does temperature have on fermentation and production of flavors?

Fermentation temperature is an “environmental condition” similar to OG, pH, pressure, pitch rate, etc.  In general, warmer temperatures will increase fermentation speed, increase ester production, and increase overall yeast flavors.  At cooler temperatures, yeast produce a more neutral beer, in general. 

This image shows the Safbrew WB-06 speed of fermentation (drop in degrees Plato) over time at three different fermentation temperatures: 16, 20, and 24°C (60.8, 68 and 75.2°F).  As you can see, the 16°C fermentation takes 6 days longer than the 24°C!

What I think is interesting is that different strains perform different ways.  Here is an image of how one of the Fermentis strains, Safbrew WB-06, performs in cooler temperatures, where it produces more isoamyl acetate (banana flavor).

Unfortunately (and fortunately for us as brewers), there are these differences between strains, where some will produce more of a certain chemical at lower temperatures, where others will produce more at higher temperatures.  Generally speaking though, yeast will produce more flavor compounds at higher temperatures.

What are the flavors produced by ale yeast?  

Ale yeast produce a wide variety of flavor and aroma compounds.  It is important to remember that the yeast is producing these compounds to develop the aroma and flavor in beer, they are simply just living in the environment that the brewer puts them into and most flavor and aroma compounds can be related to the stress of the yeast.  If you read the first installment of this Q&A with David and I and you took the time to look at that HUGE pdf image that I had him put in, you will see hundreds of compounds produced and altered by the yeast.  Each of those will have a different flavor and aroma and more importantly, a different human threshold.

The main flavors that brewers care/think about are phenolics (covered in the last installment of this), alcohols, and esters. 

What causes ale yeast to produce more or less of these esters? 

Esters are generally created in stressful environments.  Esters are actually a compound that is formed by the yeast or simply by accidently being bound in the aging beer.  It is the combination of different alcohols and carboxylic acids.  More esters are generally produced in warm fermentations, wort with low dissolved oxygen (Acetal CoA can be in excess in low O2 environments), lower pitch rates (more cell growth), and tall thin fermenters.  Generally, less esters are produced with an increased fermenter pressure.  It is also important to understand the different human threshold levels (ex. isoamyl acetate has a human threshold of 1.4ppm while ethyl acetate has a human threshold of 33ppm).

If a brewer wants to make extremely "clean" ale with very little ester, what advice would you give him or her?

In general, if you want to create a more neutral beer (low ester), you would over pitch slightly, keep the fermentation cooler than usual and if possible, keep some back pressure on the fermentation (not easy for home brewers, I know).  In addition, strain selection is important.  If a strain is more likely to produce esters in comparison to another, obviously, choose the low ester producer.  The same can be said about higher (superior) alcohols.

If a brewer wants to enhance these flavors (esters) what advice would you give?

Basically… the opposite of what I said above.  Choose a strain that is known to produce a lot of esters and higher (superior) alcohols.  Ferment warm, with a low pitch rate and little back pressure.

You have all been told that esters are bad, esters are neither bad or good, they are a tool for you to shape and create the beer you want.  Some fruity ale esters are important in many English beers, and in american , IPA, DIPAs, Belgians, and German Wheat beers

Ale yeast can also produce Phenolic flavors... Belgian flavors how does a brewer enhance these flavors?

The best ways to increase the phenolic flavor in beer is ingredient selection and strain selection.  In order for the yeast to produce phenolic flavors, they need the precursors (ex. ferrulic acid for 4-vinyl-guaiacol {4-VG}) and the yeast need the POF+ (phenolic off flavor positive) phenotype.  Some strains have that and others do not.

The malts that are highest in ferrulic acid are wheat malts.  In addition to the malt having that compound, the brewer can use step mashing to promote the extraction from the ingredients.  The rest that you will want for the ferrulic acid would be somewhere around 109-113°F.

So practically, to make a great abbey style ale, you need some wheat and you need to step mash?

Yes, and you need a yeast that has the POF+ phenotype.  Now, I have to make a comment that maltsters, currently, are doing a great job at modifying the malt, so the step mash isn’t completely necessary… it just is if you want to increase the phenolic expression by the yeast.

Are there specific sugars that ale yeast doesn't digest?   And how can brewers know what malts are high in these sugars?   

There is a specific group of sugars that ale yeast (typically) won’t ferment: dextrins.  Dextrins are a group of complex carbohydrates that most yeast are unable to pass across their membranes.  There are malts that are named specifically dextrin malt.  Some are hidden in the name (ex. "Carapils"). 

So wort composition is important?

Wort compositions is very important. 

When looking at the visualization above, it is easy to see that there is a portion of the mash that is not fermentable.  This depiction also includes the proteins and other compounds, but the idea is there,  generally for malt derived wort, only 70% of what you are extracting during your mash and lauter is fermentable.  The dextrins can be made fermentable with enzyme additions, but that isn’t something that most homebrewers are looking into doing. 

Do you think there is too much focus by the majority of brewers on limiting ester flavors"?  in other words do you think many brewers now think of any esters flavors in beer?

I think that it depends on the beer style you are trying to make.  Obviously, there are certain styles that you don’t want esters in, but there are others that you want a lot of esters in (Belgian styles usually have higher amounts of esters).  What I have been promoting in the last decade is, it doesn’t matter if your beer fits a certain style guideline or if it doesn’t.  usually, you are making the beer for yourself and your friends and in that way, you should make whatever type of beer you want to: low or high ester amounts.  If you are looking to enter a competition, then I would say, try to follow what the BJCP says; after all, the BJCP was created for homebrew competitions and it clearly states that in the opening of the document.

What unwanted off flavors can ale yeast produce?   and how do you limit them?

There are simply too many to list and how to limit them all. 

I will cover the big ones here but most can be limited by thinking about the stress level of the yeast:

Cidery notes – generally can be explained as a lack of yeast nutrition due to adjunct addition – avoid by decreasing the amount of adjunct or addition of a complex yeast nutrient (not just DAP) (Diammonium Phosphate)

Excess sulfur – generally due to autolysis – avoid by moving the beer to secondary after fermentation slows/ends

Meaty notes – partially or fully autolyzed yeast – avoid by moving the beer to secondary after fermentation slows/ends or make sure the alcohol level isn’t too high (alcohol degrades cells)

Aldehydes – produced naturally during fermentation and are later reabsorbed by yeast – allow the beer to be in contact with yeast for more time

Diacetyl (vicinal diketones {VDK}) – produced naturally during the growth phase by yeast due to the lack of Valine and Isoleucine (amino acids) and is a byproduct of the yeast synthesis of these two amino acids.  Yeast will naturally absorb and assimilate this after the sugar fermentation, however it is also produced by bacteria and if you have an infection, the yeast will never be able to assimilate it all.

Soapy notes – fatty acid degradation and dead or inactive yeast degradation – avoid by moving the beer off the yeast, especially if it is a high alcohol environment

Note:  Having the yeast in contact with the beer for long periods of time is rarely a problem in home brewing.   In home brewing we are generally not dealing with amounts of yeast that can harm our beer.  But when you are brewing a huge OG beer, or adding fruit, wood, spices etc... you might consider secondary fermentation.

What general advice would you give new and intermediate brewers about brewing an ale?

Ale fermentation is the most common for home brewers because it doesn’t necessarily require any extra equipment for cooling the fermentation.  Remember that yeast do produce heat as a byproduct of fermentation, so fermenters will heat up in high fermentation.  In general, ales are more forgiving, so the brewer doesn’t need to have an exact fermentation temperature.  Additionally, understand that there are a lot more flavors in beer than just the yeast.  Malts, hops, water and adjuncts all contribute something to the flavor of the beer and understanding all of those as well will help you make the best beer you have ever made.  Yeast is the most complex part of the beer, because it is (usually) the one living part of the beer; the hops have been harvested off the bine and the barley has been harvested and malted.  For brewing ales, I always suggest to start with the suppliers guidelines and then experiment from there as it will give you a baseline and starting point (ex. Fermentis produces the 11.5g sachets for 5 US gallons of beer, but you could always use more or less to find out what happens).  We also recommend a temperature range, but you can ferment above or below that.  That is the exciting part of homebrewing to me… you can do whatever you want and make it completely your own!