How important is it to control the temperature of a yeast starter?

[Finlandbrews]

Is temperature control as important during preparation of a yeast starter compare to during fermentation? What should be the temperature of a yeast starter for an ale and lager strain? Does it make sense to make a starter at same temperature as the one planned during my fermentation or just the temperature at which I will get the healthiest yeast?

 

[brew_darrymore]

I don't brew lagers, so no experience there.

My ale yeast starters are done at room temperature, 72-78°F (22-26°C).

I ferment for 2 days, cold crash for 2 days and decant the spent oxidized starter beer.

 

[johngaltsmotor]

From what I have read you are more concerned about making healthy yeast during the starter reproduction phase. You do not need to be as concerned about the temperatures that produce undersirable flavor compounds as you will decant off the liquid with those flavors when you transfer to your wort. Then slowly transition them from ideal reproduction temperature to ideal fermentation temperature after adding to the wort to avoid shocking them.

 

[Calder]

I've never made a lager, but in my experience, starter temp doesn't matter.

Yeast actually prefer temps in the 90s, so from a purely propagation point of view, that might be the better temp .... we just don't like the by-products it produces at those temps (for most yeasts - some are recommended for fermenting at those temps).

 

[Queequeg]

I do my starters at 72F, higher temperatures will produce a higher final cell count but more mutants. 72F is supposedly the optional temperature for good growth and minimal mutants.

 

[gometz]

For lagers, I'll make a big starter, crash the night before, decant the liquid while brewing, then let it cool in the fermentation fridge with the wort over night. Then I'll do a final aeration, and pitch the yeast. But the starter itself stays at room temp while propagating.

 

[bondra76]

This may be a stupid question, but how do you guys decant off the liquid?

I am pouring my whole starter into my beers....

So I am supposed to cold crash, and then pour out most of the liquid? Do I keep just enough liquid to maintain a slurry so I can still pour the yeast out of the flask?

 

[TheMadKing]

The purpose of a starter is to make yeast babies, so you want the temperature to be ideal for cell metabolism, not ideal for a flavor profile. 75-80F for a starter wouldn't be bad. Much below 70F and you could stunt your starter and short yourself on cells. Warmer is better for yeast activity (to a point)

You just have to make sure you match your starter/slurry temperature to your wort before pitching, and change the temperature slowly (over an hour or two). If you are pitching a 70 degree starter into a 50 degree lager wort, you run the risk of shocking and stressing your yeast, so it's best to cool your starter to 50 degrees first.

This may be a stupid question, but how do you guys decant off the liquid?

I am pouring my whole starter into my beers....

So I am supposed to cold crash, and then pour out most of the liquid? Do I keep just enough liquid to maintain a slurry so I can still pour the yeast out of the flask?

Correct, you shouldn't pitch a starter that's more than 5% of your total wort volume or you can have off flavors pop up. So you cold crash for ~48 hours, pour off the wort on top, leave enough to swirl it and make a slurry, let it warm to room temp (or wort temp) and pitch.

 

[Finlandbrews]

Can the cold crash kill the yeast viability and growth from a radical change in temperatures? If I'm correct, how do you proceed to gradually lower temperature of your yeast starter? Thanks

 

[TheMadKing]

It won't hurt viability that I've ever heard, yeast go dormant when then get cold, not die. The temperature change from putting it in fridge is slow enough to not bother it. It's very sudden temperature changes that are bad.

Think about plunging into cool water vs sitting in the bath too long and it gets cold.

 

[MaxStout]

Can the cold crash kill the yeast viability and growth from a radical change in temperatures? If I'm correct, how do you proceed to gradually lower temperature of your yeast starter? Thanks

Put the starter in your fridge overnight. Cold-crashing just makes the cells go dormant, it won't kill them (unless you freeze them). It also causes them to flocculate, so you can easily decant most of the spent wort without pouring out your yeast. It's good to decant off most of the spent wort, as that is foul-tasting and can add off-flavors to your beer. Keep a few hundred ml of spent wort in the container, as you'll need a little to slosh around the yeast to ensure it all pours out when you pitch. That small amount of spent wort won't affect you beer. You just don't want liters of spent wort going in.

On brew day, take the starter out of the refrigerator and allow it to gradually rise to near the temp of your wort. You do not want to pitch yeast that is much colder than the wort.

 

[Finlandbrews]

Very good tips thanks. Just some more questions what would be a good temperature for the yeast in the fridge? Also why not pouring all the wort on top of the cake and replacing it by adding a little of distilled water? Thanks

 

[TheMadKing]

Very good tips thanks. Just some more questions what would be a good temperature for the yeast in the fridge? Also why not pouring all the wort on top of the cake and replacing it by adding a little of distilled water? Thanks

Anywhere between 33-40 degrees is fine, and the normal range for most fridges.

You could do, but there's no benefit that I can think of.

However, I usually do a vitality starter on brew day.

So after I cold crash and decant off my liquid, I let it warm to room temp and add 500mL of fresh 1.040 wort and put it back on the stir plate for 3-4 hours and just dump the whole thing in. This ensures that the yeast are metabolically active and ready to immediately go to work on your beer.

I'm not going to objectively say there is a benefit to doing this, but I do have krausen within 4 hours almost every time, and it works well for me.

 

[Gavin C]

Is temperature control as important during preparation of a yeast starter compare to during fermentation? What should be the temperature of a yeast starter for an ale and lager strain? Does it make sense to make a starter at same temperature as the one planned during my fermentation or just the temperature at which I will get the healthiest yeast?

Not important.

Room temperature is indicated for starters regardless of what type of beer you are making. Ale or lager, it matters not.

 

[kevink]

Also why not pouring all the wort on top of the cake and replacing it by adding a little of distilled water? Thanks

I like to pour it all off then add some real, chilled wort to it right after I start chilling my batch (I use a CFC). The yeast get the first of the chilled wort. By the time I pitch there's usually a lot of activity in the flask. I have no idea if this is good practice or not.

 

[Brettomomyces]

Anywhere between 33-40 degrees is fine, and the normal range for most fridges.

You could do, but there's no benefit that I can think of.

However, I usually do a vitality starter on brew day.

So after I cold crash and decant off my liquid, I let it warm to room temp and add 500mL of fresh 1.040 wort and put it back on the stir plate for 3-4 hours and just dump the whole thing in. This ensures that the yeast are metabolically active and ready to immediately go to work on your beer.

I'm not going to objectively say there is a benefit to doing this, but I do have krausen within 4 hours almost every time, and it works well for me.

I was thinking about starting to do that, vitality starters. Are you using wort from the brew day or making it fresh? My idea was to simply pull off 1-2L (I do 10g batches) from the beer on the way to the fermenter, give it a couple hours to become active on the stir plate and then pitch the whole thing.

 

[TheMadKing]

I was thinking about starting to do that, vitality starters. Are you using wort from the brew day or making it fresh? My idea was to simply pull off 1-2L (I do 10g batches) from the beer on the way to the fermenter, give it a couple hours to become active on the stir plate and then pitch the whole thing.

I usually make it fresh because I don't want to wait until I'm finished mashing to get it on the stir plate, but I've heard of many people doing what you suggest with success.

 

[flugelizor]

I notice there is a majority here recommending cold crash at high krausen.
I read in some yeast texts that when yeast comes to the end of the fermentation cycle it stores glycogen for use during the next lag phase. So from there I would guess maybe a healthier yeast is produced by letting the yeast ferment and settle, then discard the top, or pitch the whole thing during high krausen.

Thoughts or comments?

 

[TheMadKing]

I notice there is a majority here recommending cold crash at high krausen.
I read in some yeast texts that when yeast comes to the end of the fermentation cycle it stores glycogen for use during the next lag phase. So from there I would guess maybe a healthier yeast is produced by letting the yeast ferment and settle, then discard the top, or pitch the whole thing during high krausen.

Thoughts or comments?

Yeast synthesize glycogen as a food storage for when nutrient levels drop. Essentially like fattening themselves up for hibernation. The lag phase of the yeast life cycle is not when they are using glycogen for survival, but when they are metabolizing oxygen go produce MORE glycogen for thicker cell walls so they can begin budding.

If you allow your starter to ferment out fully and the glycogen reserves to build up, then yes, the yeast cells from your starter will likely bud faster. However, the cells in your starter will make up a small part of the total number of cells that will be produced, so very little is gained IMO by taking the time to allow them to build glycogen stores.

This would be like sending 10 women pregnant with triplets to an island with only enough extra food for the original 10 people, and then the 30 new kids will have to live off the bounty of the island.

Remember the goal with yeast is to make it digest sugar, not prepare it for long term survival.

As long as you oxygenate your wort well, the yeast will synthesize all the glycogen it needs to get the job done and flucculate.

My $.02

I'm not a microbiologist, but I am dating one (no really)

and I stayed at a holiday inn once

 

[bondra76]

Correct, you shouldn't pitch a starter that's more than 5% of your total wort volume or you can have off flavors pop up. So you cold crash for ~48 hours, pour off the wort on top, leave enough to swirl it and make a slurry, let it warm to room temp (or wort temp) and pitch.

Thanks that's very helpful. Biggest takeaway is that I really need to make a starter 4-5 days in advance vs. 1-2.

 

[Natdavis777]

Ive made lager starters @ room temp with no issues. Just pitched the slurry at the desired fermentation rate.

 

[A2HB]

So what if your "room temp" is like 90-100F during the starter propagation, would that have a negative effect on cell multiplication? It's extremely hot in my place right now, like mid 90's all day, and I'm worrying about the temp being so high in here. I started making the WLP 060 starter last night for my saturday brew day and this morning there was a nice krausen in my flask but when I came home from work this afternoon it was completely gone. I'm just looking for a little reassurance I didn't mess this up, I would hate to pitch my yeast and then find out the fermentation is stalled or messed up cause the temp was too high during the starter stage. Anybody have any experience with doing a starter in this high of ambient heat, did your beer turn out ok still? Should I plan on pitching more yeast? Thanks!

 

[MaryB]

I make my starter 24 hours before I plan to pitch, pitch the entire contents because it is in active fermentation. My kitchen is around 74 degrees so not warm.

 

[TexasGuy]

To paraphrase the thread, If I want to brew on Monday:

• On Saturday morning, boil some DME in 2 liters of water (calculated in the online calculator) and cool it to room temp. My kitchen sits around 69 degrees
• Pull my smack pack out of the fridge
• Smack it
• Put it in the cooled extract water
• Put it on the stir plate and let it sit on the counter loosely covered for Saturday and Sunday
• Sunday night, put it into the fridge and go to bed
• Pull it out Monday morning. Pour the liquid off the settled yeast
• Let it warm up slowly to pitching temp.
• Use a little wort to get it off the bottom and pour it into the wort.

Thoughts?

 

[Gnomebrewer]

There are many ways to skin a cat. And to necro threads.

Personally, I prefer to make a starter about 12 hours before it'll get pitched, hold it at the same temperature as the wort it will get pitched in to (to prevent thermal shock) then pitch the entire starter (without decanting) into the chilled wort. Account for the DME and water in the recipe formulation. It's called a 'vitality starter'.

 

[Gulo_gulo]

temperature of a yeast starter for an ale and lager strain?

All I've ever read and done is that the low to mid-70s is good for both.

 

[TexasGuy]

In some videos I watched, op would start with 1 quart of water and DME, then the next day add another quart of water and DME, then another, then another. Is thee any reason not to start with 2 liters of water amount of water and DMW if the calculator says two liters will get the job done?

 

[TexasGuy]

Ive ended up with a 5L flask. I see people using foam stoppers. Is this necessary? Or can I cover with foil?

Do I need to poke holes in it so fresh air (oxygen) can get in while it is on the stir plate for a day or two? What about using an airlock?

 

[CodeSection]

Ive ended up with a 5L flask. I see people using foam stoppers. Is this necessary? Or can I cover with foil?

Do I need to poke holes in it so fresh air (oxygen) can get in while it is on the stir plate for a day or two? What about using an airlock?

I have a 5L flask as well and use foil to cover the top. DO NOT poke holes in the foil. You want to keep it sanitary as possible and not allow any nasties to get in. Be sure to spray down the foil and flask rim with Starsan before applying the foil to the top. Matter-of-fact, I soak the folded foil in Starsan while I heat the starter wort.

I have seen on Youtube where people have used an airlock. I haven't tried it as I don't see the need....Plus, I've read where people dropped the wrong sized bung into the flask....

 

[Gulo_gulo]

Same here, foil, wrapped fairly tightly just in case there are insects around that might want to check it out. When I swirl (stir plates are better) air can get in/out no problem. No holes in the foil.

 

[FswBG]

I typically pitch the whole starter right off the stir plate. Recently I have been thinking it might be best to decant to keep extract flavouring out of the wort.

Do you chill after 24 hours on a stir plate, decant, and let it free rise up to pitch temps? Any recommendations are appreciated.

Making a starter at the moment actually. [emoji481]

 

[Robert65]

I have a 5L flask as well and use foil to cover the top. DO NOT poke holes in the foil. You want to keep it sanitary as possible and not allow any nasties to get in. Be sure to spray down the foil and flask rim with Starsan before applying the foil to the top. Matter-of-fact, I soak the folded foil in Starsan while I heat the starter wort.

I have seen on Youtube where people have used an airlock. I haven't tried it as I don't see the need....Plus, I've read where people dropped the wrong sized bung into the flask....

No need to sanitize the foil, foil is sterile right off the roll, which is one reason it is used for this purpose in labs. (It's also handy whenever you need a little sanitary surface to set things on.) Cover the flask loosely to allow gas exchange -- CO2 out and O2 in. Bugs riding on dust can only fall down, they won't be able to negotiate the twists and turns to get up under the foil. An airlock should not be used on a starter because it won't let O2 in. If you boil the medium in the flask with the loose foil on it, steam will take care of sanitizing the lip of the flask.

 

[CodeSection]

I typically pitch the whole starter right off the stir plate. Recently I have been thinking it might be best to decant to keep extract flavouring out of the wort.

Do you chill after 24 hours on a stir plate, decant, and let it free rise up to pitch temps? Any recommendations are appreciated.

Making a starter at the moment actually. [emoji481]View attachment 658928

First of all, I would not leave the flask open like that. I would cover it with foil.

Once the starter is made, my process involves pouring some into a quart canning jar since I overbuilt the starter so as I have can make another starter and overbuild later. Then I put the 5L flask in the refrigerator for 12-24 hours to let everything settle. On brew day, I take it out of the refrigerator and decant most of the wort leaving only 1/2"-1" of it on top of the yeast cake.

I leave the flask out to warm up while I brew. Then when it is time, I swirl the small amount of wort in the flask to stir up the yeast cake and then pitch.

 

[kh54s10]

Thanks that's very helpful. Biggest takeaway is that I really need to make a starter 4-5 days in advance vs. 1-2.

No need for 4-5 days. The starter is pretty much done if on a stirplate in 18 - 24 hours then chill overnight and decant the next day just before pitching.

There is also a growing crowd that put the yeast starter in a large container - shake it up vigorously then leave it be. The large volume of air I believe is the key.

"
RPIScotty

I’m Derek Scott. I’m a Category 26 kind of guy.
Dec 24, 2015
1,851
921
Posted Jan 4, 2016
I use the "Shaken, not Stirred" method. Prepare 1L of starter of starter wort and put it in a 1Gal glass jug. Cap it and shake the container until you've nearly filled it with foam. Pitch your yeast to the starter. Pitch the starter to your wort at high krausen, starter wort and all.

Dead simple method and equipment. Very healthy yeast with reduced lag times.

 

[TexasGuy]

What should the starter smell like? My wife says it sells slightly sour, but not bad.

Also, I’v got a little bit of burnt DME at the bottom of my flask...had the fire too high. I’d say 15% of the flask bottom is covered.

Curious if I should start over given these two points.

 

[mashpaddled]

Generally a starter doesn't need temperature control unless you leave it in a particularly cold or hot environment. Room temperature for most people will be fine for most yeast.

If you have yeast that needs a lot of heat then you will need to provide those conditions for the yeast to build up a healthy population quickly. For example, I have a mixed saison culture that is sluggish at anything below ~78F so I have to pump a lot of heat into the starter if I don't want to wait two weeks for it to reach peak population. It is an unusual culture.

 

[CodeSection]

What should the starter smell like? My ice says it sells slightly sour, but not bad.

Also, I’v got a little bit of burnt DME at the bottom of my flask...had the fire too high. I’d say 15% of the flask bottom is covered.

Curious if I should start over given these two points.

Don't you just hate auto-correct? I can't comment about a sour smell in a starter....I've never noticed such as smell. Perhaps, it may be associated with the burnt DME? It sounds as if the DME was not mixed well. You pitched the yeast, yes? Then noticed the smell after the yeast took off? Or were you just smelling the wort only without the yeast?

My process of making a starter is different from yours. I DO NOT heat my 5L flask directly on the gas stove top. Instead, I put the flask in a large pot that is filled with water with the water line about an inch above the wort line in the flask. I boil the water which in turns boils the wort.

The benefits with the above method is I do not worry about burning any DME and I do not worry about wort spilling all over the place in case the flask cracks or breaks. I use a glove and swirl the solution every five minutes or so. The downside to this method is that it takes longer to bring the wort to a boil.

When I'm ready to cool, I cover the flask with tin foil and then I fill the kitchen sink basin with very WARM water (so not to cause such a temp change that could result in cracking or breakage to the flask) and the put the flask in it. After a couple of minutes, I start draining the sink while adding cooler water. Fill basin again and swirl flask and let it sit there. Every five minutes I change out the water and swirl the flask. I repeat the process until I reach pitching temperature.

This time of the year the water is cold enough that I do not need to add frozen water that is in 2 liter bottles to add to the sink water. I the summertime, I need frozen water bottles.

 

[kh54s10]

What should the starter smell like? My ice says it sells slightly sour, but not bad.

Also, I’v got a little bit of burnt DME at the bottom of my flask...had the fire too high. I’d say 15% of the flask bottom is covered.

Curious if I should start over given these two points.

The smell of a starter depends a lot on which yeast. I have had some that smelled terrible to me but produced great beer. The burnt DME should not be a big problem. I boiled in my flask a couple of times then decided that was too much trouble. I now boil for about 30 seconds in a pot. Put the pot in the freezer until it is cooled. Then pour it in the flask, add the yeast and put it on the stirplate.

 

[sleev-les]

I make my starter 24 hours before I plan to pitch, pitch the entire contents because it is in active fermentation. My kitchen is around 74 degrees so not warm.

This is what I do. I use one of the canned worts though. Dump it in, fill it with water, add the water and pitch the yeast. Put it on a stir plate and let it run for 24 hours and pitch the entire contents. Haven't had an issue yet.

I've never had a thick slurry since the stir plate is running. But its also not a large volume of wort as I saw someone mention the 5% total volume.

 

[TexasGuy]

I went ahead and dumped it and started over. If this one smells the same, I'll know the last one was good. And this time, I'm doing a single step with 3L instead of a 2 step starting with 2L to make it easier.

And...turns out the burnt DME was on the outside of the flask...no matter how hard I scrubbed the inside of the flask, it wasn't coming off! DOH!