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

[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
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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!

 

[CodeSection]

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!

Glad you figured it out...

 

[fudgenstuff]

Hi,
I have been fermenting an Irish Stout extract at 20C for 12 days and it is still bubbling every 15 seconds, should i wait to bottle?
Thanks,
iAn

 

[kh54s10]

Hi,
I have been fermenting an Irish Stout extract at 20C for 12 days and it is still bubbling every 15 seconds, should i wait to bottle?
Thanks,
iAn

Lots of things can make an airlock bubble. Best way to know is to take a gravity reading today and another one on Thursday, if the numbers are the same go ahead and bottle it. If Thursday's number is smaller - wait longer.

 

[TexasGuy]

I did a 3L starter last week, but did not get to use it over the weekend. I'm going to brew this Saturday.

My starter has been sitting in the refrigerator ever since. Should I let it return to room temperature before or after I decant the starter wort?

 

[CodeSection]

I did a 3L starter last week, but did not get to use it over the weekend. I'm going to brew this Saturday.

My starter has been sitting in the refrigerator ever since. Should I let it return to room temperature before or after I decant the starter wort?

Decant when you first remove it from the refrigerator. Then let it sit at room temp while you are brewing.

 

[TexasGuy]

@CodeSection Thanks...so letting the starter wort sit on top off it for a couple of weeks in the fridge is nothing to worry about?

Just did initial burn on my outdoor burner (pick up a Hellfire) and boil leak teat on on a used keggle...hoping to actually get to make my high gravity blood orange wit tomorrow

 

[CodeSection]

@CodeSection Thanks...so letting the starter wort sit on top off it for a couple of weeks in the fridge is nothing to worry about?

Just did initial burn on my outdoor burner (pick up a Hellfire) and boil leak teat on on a used keggle...hoping to actually get to make my high gravity blood orange wit tomorrow

You will be fine. Before you do anything else with your brew (milling grain, etc), first remove the starter from your refrigerator and decant most of the wort off the yeast bed leaving about an 1/2" of wort on top of the yeast bed. Then swirl the starter and let the starter slurry warm up while you are brewing. When mashing and boiling, I occasionally swirl the starter to keep everything mixed.

It's always exciting using new pieces of equipment. Good luck tomorrow!

 

[kh54s10]

You will be fine. Before you do anything else with your brew (milling grain, etc), first remove the starter from your refrigerator and decant most of the wort off the yeast bed leaving about an 1/2" of wort on top of the yeast bed. Then swirl the starter and let the starter slurry warm up while you are brewing. When mashing and boiling, I occasionally swirl the starter to keep everything mixed.

It's always exciting using new pieces of equipment. Good luck tomorrow!

I would do this with the exception of leaving less wort to swirl up the yeast. Maybe a little under 1/4 inch. But for smaller starters, especially with good timing, I would pitch the whole starter at high krausen. These less than 1 liter starters.

 

[TexasGuy]

I gave the wort a shot of oxygen (first time using) right before I pitched the wort last night around 11:00 pm, but couldn't get anything except large O2 bubbles. After I put everything away, I went to clean the O2 wand, and noticed the compression fitting was loose, so very likely nothing got dissolved. I let it sit and went to bed.

Got up at 6:30 am, and no change in in OG (using a tilt to read). Gave it about 90 seconds of dissolved O2 (worked much better this time with the fitting tightened).

OG 1.078, current temp is 69, using Wyest 3944. How long should I wait to see good activity? And since my first O2 shot was a dud, should I gas it again when I get home this evening?

 

[CodeSection]

I gave the wort a shot of oxygen (first time using) right before I pitched the wort last night around 11:00 pm, but couldn't get anything except large O2 bubbles. After I put everything away, I went to clean the O2 wand, and noticed the compression fitting was loose, so very likely nothing got dissolved. I let it sit and went to bed.

Got up at 6:30 am, and no change in in OG (using a tilt to read). Gave it about 90 seconds of dissolved O2 (worked much better this time with the fitting tightened).

OG 1.078, current temp is 69, using Wyest 3944. How long should I wait to see good activity? And since my first O2 shot was a dud, should I gas is again when I get home this evening?

While the first attempt of adding O2 did not produce the smaller bubbles, the second attempt did. I see no reason to add anymore O2 this evening. I would suggest you now keep the fermenter sealed....

 

[TexasGuy]

After 8 days of fermenting, I still have airlock activity. I’m at current gravity 1.043, down from SG 1.78...my Tilt says I'm about 46% attenuated (yeast is rated for 72%) and an ABV of 4.73%. I’m currently at 68°F without helping it with supplemental heating.

At what point should I consider helping it along? My goal for FG is 1.021 or less and 8% or more ABV. I’m not trying to match a style, just end up with a nice beverage that doesn’t require drinking a 6-pack to relax at the end of the day when I’m not in the mood for whiskey.

 

[David Baker]

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?

The latter. The whole object of a starter is to grow the yeast. In summer keep it at room temp. In winter keep it warm.

 

[David Baker]

After 8 days of fermenting, I still have airlock activity. I’m at current gravity 1.043, down from SG 1.78...my Tilt says I'm about 46% attenuated (yeast is rated for 72%) and an ABV of 4.73%. I’m currently at 68°F without helping it with supplemental heating.

At what point should I consider helping it along? My goal for FG is 1.021 or less and 8% or more ABV. I’m not trying to match a style, just end up with a nice beverage that doesn’t require drinking a 6-pack to relax at the end of the day when I’m not in the mood for whiskey.

Sounds as if you have a "big" beer there. I suggest leave it alone. Let it be. Less fiddling with it and let the yeast do its work. Maybe at 2 weeks rack it off the dead yeast and then leave it alone - for weeks or even months.

 

[theothermillion]

With it being winter, my current room temp is ~64 during the day and I let it drop to 61 at night. Any suggestions for keeping the starter closer to 70 - 74?

 

[FswBG]

With it being winter, my current room temp is ~64 during the day and I let it drop to 61 at night. Any suggestions for keeping the starter closer to 70 - 74?

If you have a spare temp controller available you can set up a heating box. I used a styrofoam cooler and a heating pad to make a bread proofing box for my wife that will double as a starter box during winter. If not, you can always set up a heater in a spare bathroom or something to get the temps up a bit.

 

[theothermillion]

If you have a spare temp controller available you can set up a heating box. I used a styrofoam cooler and a heating pad to make a bread proofing box for my wife that will double as a starter box during winter. If not, you can always set up a heater in a spare bathroom or something to get the temps up a bit.

Great idea! Thanks. Just made that starter and put it in the spare bathroom next to my space heater. I do have a heat pad but not sure how that would work with a stir plate. Would need the spare controller anyways.

 

[robert.balsinger]

Great idea! Thanks. Just made that starter and put it in the spare bathroom next to my space heater. I do have a heat pad but not sure how that would work with a stir plate. Would need the spare controller anyways.

My experience is that my small stir plate adds 4 or 5 F to the temperature of the surrounding air.

 

[KeizerBrewr]

I put an adhesive thermometer on my 2L flask to help give me an idea of where the temps are at. I typically chill my starter wort to 72F, let the stir plate run on high for 10 minutes to aerate, then turn down to my desired RPM and pitch yeast, cover the top with sanitized foil and wrap the whole thing with a kitchen towel to keep the heat in and more constant. Works for me, YMMV

 

[deuc224]

Ok if you do a 2 step starter how many of you decant it before doing the second step? It would save me a full day if I just went from propped yeast in toa bigger starter.

 

[KeizerBrewr]

Ok if you do a 2 step starter how many of you decant it before doing the second step? It would save me a full day if I just went from propped yeast in toa bigger starter.

I do purely because I only have a 2L flask. Once the first step is complete, I crash it, decant the supernatant and then begin the second step.