The effect of yeast on beer flavors

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allynlyon

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I'm really new to brewing and went to my LHBS this week to pick up my next kit. The store clerk was awesome and helped explain yeast starters to me so that I could save money. We began discussing the affect the yeast has on beer. I realized for the first time that most of the beer I really enjoy are Belgian beers. For example, normally I am not a big fan of IPA's. I am just not a fan of the bitter bite that most have that being said he had brewed a Belgian IPA that was fantastic.

I didn't realize how much of an influence the yeast had over the balance of a beer. Maybe this seems obvious to everyone else and this is a moment I should be embarrassed to be sharing. If so feel free to mock away.

That being said I was curious to learn more about different yeast and what it's affect on beers are. I found a little information about what esters different types of yeast throw, but I thought someone here might have more information.

Thanks in advance.
 
I'm really new to brewing and went to my LHBS this week to pick up my next kit. The store clerk was awesome and helped explain yeast starters to me so that I could save money. We began discussing the affect the yeast has on beer. I realized for the first time that most of the beer I really enjoy are Belgian beers. For example, normally I am not a big fan of IPA's. I am just not a fan of the bitter bite that most have that being said he had brewed a Belgian IPA that was fantastic.

I didn't realize how much of an influence the yeast had over the balance of a beer. Maybe this seems obvious to everyone else and this is a moment I should be embarrassed to be sharing. If so feel free to mock away.

That being said I was curious to learn more about different yeast and what it's affect on beers are. I found a little information about what esters different types of yeast throw, but I thought someone here might have more information.

Thanks in advance.

Yup... Take it further and the different hops add different character. The time the hops are in the boil change the character. The type of grain change the character. The mash temp changes the character...etc.

Your problem with IPA probably isn't the yeast but the hops. Belgian IPA generally use a European hop varieties. This gives a subdued hop profile compared to an IPA. I'm with you. I like a very hoppy beer full of flavor and aroma, but I'm not huge on the puckering bitterness. It's all about balance.

You can make a smoother IPA and do less bittering by doing more hops late in the boil

Here's a good read: http://www.mrmalty.com/late_hopping.php

There are tons of resources online that breaks down the flavor profiles hops and yeast give. You should get beer smith and start making your own recipes. You can figure out if you want more fruit or spice character then choose the proper yeast for that profile... Then you can choose your hops based off If you want more citrus or spice ... etc. You can also choose different AA (alpha acids) depending on how much bittering you want.. Etc.

This is why brewing is both a science and an art. And this is why there are literally millions of flavor profiles that can be achieved.
 
Yup... Take it further and the different hops add different character. The time the hops are in the boil change the character. The type of grain change the character. The mash temp changes the character...etc.

Your problem with IPA probably isn't the yeast but the hops. Belgian IPA generally use a European hop varieties. This gives a subdued hop profile compared to an IPA. I'm with you. I like a very hoppy beer full of flavor and aroma, but I'm not huge on the puckering bitterness. It's all about balance.

You can make a smoother IPA and do less bittering by doing more hops late in the boil

Here's a good read: http://www.mrmalty.com/late_hopping.php

There are tons of resources online that breaks down the flavor profiles hops and yeast give. You should get brew smith and start making your own recipes. You can figure out if you want more fruit or spice character then choose the proper yeast for that profile... Then you can choose your hops based off If you want more citrus or spice ... etc. You can also choose different AA (alpha acids) depending on how much bittering you want.. Etc.

This is why brewing is both a science and an art. And this is why there are literally millions of flavor profiles that can be achieved.

I knew the hops and grains had a large impact on aroma and flavoring as well as bittering. Out of all the different brewing ingredients hops are where I am most comfortable. I thought yeast basically had served a chemical purpose and didn't realize the impact could carry over to flavor.

Thanks for the tip on brewsmith, I was wondering how one made that leap from kits to making their own recipe. Right now it all seems so overwhelming trying to understand the affect that each grain/hop/yeast variety or combo of these have on the aroma and flavor.

I can't wait to create my own recipe after I learn more.
 
Beer smith makes it so easy.

Sit back and think what type of flavors you like. Then choose the style it fits in (there are tons of resources to determine that) then build the recipe. Beer smith helps you keep it in style. Then you can choose the characters you want carried over with the hops, yeast, etc.

For instance, my last recipe was an all grain for pumpkin pie graff.

I wanted to bring out the biscuit flavor to simulate a crust, so I went with Maris otter 2 row.

Then I wanted my hops to provide spicy tone with a low bittering (~4% AA) I went with crystal hops. I split it up in the boil to keep the IBU down to 10. It came out to .75 @ 60 then the rest @ 15.

Finally I wanted to bring out a butter flavor (again for that crust flavor) so I used Ringwood yeast (1187) it is known to produce diacetyl.

It turned out fantastic and has been a huge hit. 5 gallons didn't even last a month :-/ good thing I brewed more :)

I actually brought some in a growler to a wedding this afternoon. The couple who got married toasted with it. And the groom was upset when the growler was empty.
 
Brew smith makes it so easy.

Sit back and think what type of flavors you like. Then choose the style it fits in (there are tons of resources to determine that) then build the recipe. Beer smith helps you keep it in style. Then you can choose the characters you want carried over with the hops, yeast, etc.

For instance, my last recipe was an all grain for pumpkin pie graff.

I wanted to bring out the biscuit flavor to simulate a crust, so I went with Maris otter 2 row.

Then I wanted my hops to provide spicy tone with a low bittering (~4% AA) I went with crystal hops. I split it up in the boil to keep the IBU down to 10. It came out to .75 @ 60 then the rest @ 15.

Finally I wanted to bring out a butter flavor (again for that crust flavor) so I used Ringwood yeast (1187) it is known to produce diacetyl.

It turned out fantastic and has been a huge hit. 5 gallons didn't even last a month :-/ good thing I brewed more :)

Oh hell now I'm never going to stop buying grain. I need a job to pay for my hobby.

Seriously though, thanks this is awesome. I'm going to go buy it now.
 
Tell me about it... The grain isn't even the major cost.

I have a pretty elaborate set-up, but I invested very little into it. I actually started out buying and re-selling home brew stuff on Craig's list. I then put the profits towards more gear I found on Craig's list.

Now I'm up to a 20 gallon blichmann boiler maker (hell of a deal on CL) and I'm fermenting in stainless steel 1/4 slim kegs under pressure using spunding valves. I have two 10 gallon mash tuns with SS bottoms and two plate chillers... I have a couple temp controlled fermentation chambers too. All for pennies really.

I spent a couple hundred dollars, but my set up would've been thousands. I'm working my way up to a HERMS.

I harvest my yeast, and soon I'm going to start making slants.

I'm a full time student. Gotta save where I can.
 
Tell me about it... The grain isn't even the major cost.

I have a pretty elaborate set-up, but I invested very little into it. I actually started out buying and re-selling home brew stuff on Craig's list. I then put the profits towards more gear I found on Craig's list.

Now I'm up to a 20 gallon blichmann boiler maker (hell of a deal on CL) and I'm fermenting in stainless steel 1/4 slim kegs under pressure using spunding valves. I have two 10 gallon mash tuns with SS bottoms and two plate chillers... I have a couple temp controlled fermentation chambers too. All for pennies really.

I spent a couple hundred dollars, but my set up would've been thousands. I'm working my way up to a HERMS.

I harvest my yeast, and soon I'm going to start making slants.

I'm a full time student. Gotta save where I can.

Suhweet. I've been looking on craigslist but haven't been finding anything pop up. Also did you mean beersmith? I'm not finding a brew smith anywhere.
 
If you really want to get a first hand look at the variation of the effect of different flavors brought on by yeast, and are interested in experimentation, brew a five gallon batch of a basic wort. Split it into five one gallon batches and pitch different yeast in each. Yes it can be a little pricey, but provides a really good base of knowledge in what the different strains will produce.
 
yes sorry beer smith my ipad likes to type it's own words all the time.

There is a learning curve to It, but the difficult part is getting your equipment profile set up.

Also you can do a trial version.
 
yes sorry beer smith my ipad likes to type it's own words all the time.

There is a learning curve to It, but the difficult part is getting your equipment profile set up.

Also you can do a trial version.

Thanks again! I downloaded it now I just need to play with it.
 
Thanks again! I downloaded it now I just need to play with it.

He also has pretty good customer service. If you have questions, he's pretty prompt to answer. He should have a new version coming out soon to fix the problems with lactose additions. I'm also hoping he makes changes to make it easier to build cider and graff recipes too. It's a good piece of software over all and will help you learn a lot. Good luck.
 
If you really want to get a first hand look at the variation of the effect of different flavors brought on by yeast, and are interested in experimentation, brew a five gallon batch of a basic wort. Split it into five one gallon batches and pitch different yeast in each. Yes it can be a little pricey, but provides a really good base of knowledge in what the different strains will produce.

Good idea! As for price couldn't I wash the yeast and reuse?
 
If you really want to get a first hand look at the variation of the effect of different flavors brought on by yeast, and are interested in experimentation, brew a five gallon batch of a basic wort. Split it into five one gallon batches and pitch different yeast in each. Yes it can be a little pricey, but provides a really good base of knowledge in what the different strains will produce.

Pricey, and using all of a smack pack is dramatically overpitching for a one-gallon brew - this will reduce the yeast's impact on flavor, which will make the experiment unhelpful.

To the OP: Make sure to only use a fifth of the smack pack in a gallon batch. This will mean discarding the rest, unless you have storage/flasks/DME/etc to culture starters from the remainder of each.
 
Pricey, and using all of a smack pack is dramatically overpitching for a one-gallon brew - this will reduce the yeast's impact on flavor, which will make the experiment unhelpful.

To the OP: Make sure to only use a fifth of the smack pack in a gallon batch. This will mean discarding the rest, unless you have storage/flasks/DME/etc to culture starters from the remainder of each.

I would like to point out that depending on the gravity of the wort the smack pack might be half instead of a fifth for proper pitch rates into one gallon. Typically (ymmv) you can expect to have proper pitch rates at one smack pack or vial into 2.5 gallons of 1.050 wort. This assumes the vials/packs were stored properly and around one month from production date. Older vials can be pitched into progressively smaller amounts of wort and still be at proper rates.
 
I knew the hops and grains had a large impact on aroma and flavoring as well as bittering. Out of all the different brewing ingredients hops are where I am most comfortable. I thought yeast basically had served a chemical purpose and didn't realize the impact could carry over to flavor.

Thanks for the tip on brewsmith, I was wondering how one made that leap from kits to making their own recipe. Right now it all seems so overwhelming trying to understand the affect that each grain/hop/yeast variety or combo of these have on the aroma and flavor.

I can't wait to create my own recipe after I learn more.

BeerSmith is awesome, and I love it for helping me dial in my brews, but I would STRONGLY encourage you to get Designing Great Beers by Ray Daniels. I don't think a better book exists for understanding the interplay between malt, hops, yeast, water and heat. I haven't gotten the new series HOPS, YEAST and WATER yet, but I suspect they would be the next best.
 
I haven't gotten the new series HOPS, YEAST and WATER yet, but I suspect they would be the next best.

Hops is good, but there's a lot of fluff. Sometimes technical stuff is snuck in a couple pages into a six-page block of trivia and anecdote. I cautiously endorse it.

I would like to point out that depending on the gravity of the wort the smack pack might be half instead of a fifth for proper pitch rates into one gallon. Typically (ymmv) you can expect to have proper pitch rates at one smack pack or vial into 2.5 gallons of 1.050 wort. This assumes the vials/packs were stored properly and around one month from production date. Older vials can be pitched into progressively smaller amounts of wort and still be at proper rates.

I oversimplified a bit, but the Wyeast smack packs are designed for pitching into five gallons of up to 1.060 wort. Half would be seriously overpitching unless he's doing an RIS or something!
 
Hops is good, but there's a lot of fluff. Sometimes technical stuff is snuck in a couple pages into a six-page block of trivia and anecdote. I cautiously endorse it.



I oversimplified a bit, but the Wyeast smack packs are designed for pitching into five gallons of up to 1.060 wort. Half would be seriously overpitching unless (s)he's doing an RIS or something!
.
 
If you're using liquid yeast, yes. Or do slants.

But when you're doing yeast harvesting, you want to make starters. So you'll want a stir plate if you don't have one.

I've only used liquid yeast. I'll have to go look at the slant sticky because I don't even know what that is. I just learned the whole making starter thing, I think I am going to attempt to make a stir plate this week. Thanks :)
 
Pricey, and using all of a smack pack is dramatically overpitching for a one-gallon brew - this will reduce the yeast's impact on flavor, which will make the experiment unhelpful.

To the OP: Make sure to only use a fifth of the smack pack in a gallon batch. This will mean discarding the rest, unless you have storage/flasks/DME/etc to culture starters from the remainder of each.

He said to make a 5 gallon batch and split it into 5-1 gallon jugs and then split the yeast. Am I confused or did you misread?
 
I would like to point out that depending on the gravity of the wort the smack pack might be half instead of a fifth for proper pitch rates into one gallon. Typically (ymmv) you can expect to have proper pitch rates at one smack pack or vial into 2.5 gallons of 1.050 wort. This assumes the vials/packs were stored properly and around one month from production date. Older vials can be pitched into progressively smaller amounts of wort and still be at proper rates.

When I was at my lhbs the guy mentioned that he thought new homebrewers chronically underpitched. I asked if you could over pitch and he said yes but it's hard. Thoughts?
 
BeerSmith is awesome, and I love it for helping me dial in my brews, but I would STRONGLY encourage you to get Designing Great Beers by Ray Daniels. I don't think a better book exists for understanding the interplay between malt, hops, yeast, water and heat. I haven't gotten the new series HOPS, YEAST and WATER yet, but I suspect they would be the next best.

Awesome I will check those out.
 
I oversimplified a bit, but the Wyeast smack packs are designed for pitching into five gallons of up to 1.060 wort. Half would be seriously overpitching unless he's doing an RIS or something!

*She* typically makes IPA, Tripels, Wheats ;)
 
He said to make a 5 gallon batch and split it into 5-1 gallon jugs and then split the yeast. Am I confused or did you misread?

Split the yeast means to use different yeasts in each batch to see the flavor profile dfferences.

And what they're saying is if you use a full smack pack, you over pitch.

The cell count is high in a vile or smack pack (generally enough cells for a 5 gal at ~ 1.050) when the yeast is over pitched, you lose out of the wanted flavors a properly pitched cell count produces.

There are calculators that help take the guess work out of the proper cell count for your beer. This is good to know when you start making your starters.

People will also experiment like this by splitting a batch and change up the dry hop regimen on each batch by trying different hops or times. It's also similar to taking a measure sample, sampling with a measured amount of spice to find the right balance, then scaling up to a full 5 gallon batch. It saves on money, and allows you to see what tastes best.
 
Split the yeast means to use different yeasts in each batch to see the flavor profile dfferences.

And what they're saying is if you use a full smack pack, you over pitch.

The cell count is high in a vile or smack pack (generally enough cells for a 5 gal at ~ 1.050) when the yeast is over pitched, you lose out of the wanted flavors a properly pitched cell count produces.

There are calculators that help take the guess work out of the proper cell count for your beer. This is good to know when you start making your starters.

People will also experiment like this by splitting a batch and change up the dry hop regimen on each batch by trying different hops or times. It's also similar to taking a measure sample, sampling with a measured amount of spice to find the right balance, then scaling up to a full 5 gallon batch. It saves on mooney and allows you to see what tastes best.


Oh oh oh I see. I missed that part (well forgot) about the 5 different yeasts. I had my head stuck in yeast washing. :)
 
*She* typically makes IPA, Tripels, Wheats ;)

Look, lady, I "simplified" pitch rates, I can "simplify" gender as well. ;)

Overpitching is not difficult, it's a gradient thing. Yeast reproduction means more yeast-contributed flavors. Underpitching causes too much yeast repro, which pushes yeast flavors over the top and also pushes some components over the taste threshold, meaning you get off flavors you wouldn't have detected otherwise.

On the reverse side, overpitching means the yeast doesn't reproduce very much, and doesn't kick out much flavor. This is a bad thing, because even very "clean" yeasts that we imagine have little flavor, like US-05 or pilsner yeasts, actually contribute a lot... those "neutral" flavors are very important.

Homebrewers do frequently underpitch, generally because they're brewing a big beer and only use one smack pack/vial/etc. It's also something of a historical thing, as White Labs formerly put significantly fewer cells in their vials than they do today.
 
Look, lady, I "simplified" pitch rates, I can "simplify" gender as well. ;)

Haha. :)

Overpitching is not difficult, it's a gradient thing. Yeast reproduction means more yeast-contributed flavors. Underpitching causes too much yeast repro, which pushes yeast flavors over the top and also pushes some components over the taste threshold, meaning you get off flavors you wouldn't have detected otherwise.

On the reverse side, overpitching means the yeast doesn't reproduce very much, and doesn't kick out much flavor. This is a bad thing, because even very "clean" yeasts that we imagine have little flavor, like US-05 or pilsner yeasts, actually contribute a lot... those "neutral" flavors are very important.

Homebrewers do frequently underpitch, generally because they're brewing a big beer and only use one smack pack/vial/etc. It's also something of a historical thing, as White Labs formerly put significantly fewer cells in their vials than they do today.


So when you make a starter how do you measure the amount of yeast that has reproduced so you don't over pitch?
 
Haha. :)




So when you make a starter how do you measure the amount of yeast that has reproduced so you don't over pitch?

There are pitch rate calculators on online. It makes thing easier. I think beer smith has one built into it too? Not sure though.

There's a general rule of thumb but I don't remember it off the top of my head. The calculator does the thinking for you anyway.

The total amount depends on the beers gravity. Some could use up to a gallon.

Normally it'll be something like 1L worth of slurry, so you start with 250ml pitch your washed yeast then step it up until you get to the 1L amount. Then put it intone fridge to crash it. Pull it out let it warm up decant and pitch.

Oh, and you don't want to make starters with dry yeast. Using dry yeast is like using a starter; however big beers may need two packets. And you also don't want to wash/save dry yeast.
 
I think there is some confusion about pitch rate on here. A normal 1.050 og ale needs 190 billion cells. This is nearly double what is in a vial/pack of yeast, and that would be at 100% viability. Over pitching is much harder to do than under pitching simply because it takes some serious work to build up that much yeast. Pitching onto an entire cake would certainly be overpitching.

Can you make good beer by over/under pitching? Absolutely! Can it be the best beer it could have been? Probably not. There are always exceptions and each yeast and brewer is unique so these are just generalizations.

If you want to get serious about yeast then I recommend the info on Mr maltys website as well as the work done on yeastcalc.com. Another great resource is the book yeast although it deals with brewery yeast propagation as well as homebrew levels.

Lastly, if you do decide to run some experiments be sure to take notes and share the results on hbt. Most of what I have learned started with people on here sharing their experiences and experiments
 
If there's confusion, it surely isn't an accident - Wyeast themselves claim their (100 billion cell) smack pack is both the correct rate, and to professional standards. Are they lying?
 
A great resource for yeast strains is both the wyeast and white labs websites. They give each strain and good descriptions of what they do, what flavors they bring, ideal temps and typical styles they are used for-generally a good place to start research on what to use for a batch of beer.

Welcome to the obsession, sounds like you're off to a great start! The book "yeast" is also something to get in your library! Yeast make beer and yes, they can have a huge effect on how you flavor profiles turn out! Even the same strain fermented at slightly different temps can yield completely different beers.

For example: WY3068 at higher temps will yield a hefeweizen strong with banana and the same strain at low temps will give off a lot of clove and almost no banana.
 
If there's confusion, it surely isn't an accident - Wyeast themselves claim their (100 billion cell) smack pack is both the correct rate, and to professional standards. Are they lying?

According to every other piece of literature I have read, yes they are lying. The accepted rate is something like .75m cells per ml per degree Plato for ales and 1.25m cells for lagers. Some beers are the exception. German hefeweizen benefits from underpitching IMO.
 
According to every other piece of literature I have read, yes they are lying. The accepted rate is something like .75m cells per ml per degree Plato for ales and 1.25m cells for lagers. Some beers are the exception. German hefeweizen benefits from underpitching IMO.

Then I'll happily stand corrected. Now I'm ticked off... thanks, Wyeast.
 
Then I'll happily stand corrected. Now I'm ticked off... thanks, Wyeast.

Sorry to be the one who breaks it to you. It made me mad when I first found out as well. Just remember that just because a beer isn't perfect doesn't mean it is bad. Plenty of good beers are made by underpitching yeast and I will happily drink them.
 
Hey, man, I'm not mad at you... I'm mad at Wyeast for making things up, and at myself for spreading their marketing claims like gospel. Officially part of the problem, here!
 
I think there is some confusion about pitch rate on here. A normal 1.050 og ale needs 190 billion cells. This is nearly double what is in a vial/pack of yeast, and that would be at 100% viability. Over pitching is much harder to do than under pitching simply because it takes some serious work to build up that much yeast. Pitching onto an entire cake would certainly be overpitching.

Can you make good beer by over/under pitching? Absolutely! Can it be the best beer it could have been? Probably not. There are always exceptions and each yeast and brewer is unique so these are just generalizations.

If you want to get serious about yeast then I recommend the info on Mr maltys website as well as the work done on yeastcalc.com. Another great resource is the book yeast although it deals with brewery yeast propagation as well as homebrew levels.

Lastly, if you do decide to run some experiments be sure to take notes and share the results on hbt. Most of what I have learned started with people on here sharing their experiences and experiments

More great info and I'll be sure to do that thanks!
 
Sorry to be the one who breaks it to you. It made me mad when I first found out as well. Just remember that just because a beer isn't perfect doesn't mean it is bad. Plenty of good beers are made by underpitching yeast and I will happily drink them.

+1 to this. You can easily get away with just pitching a vial or a smackpack, and get drinkable, even good beer. You can shake or stir your wort and not use oxygen bottles, you can dump the trub into the fermentor, skip the irish moss or gelatin or fish guts, etc, etc, etc. I'll drink them all if they taste good. But any of us could make the BEST beer we can make by standing on the shoulders of the giants, and applying some of what they KNOW makes beer better to our own!
 
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