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General Category => Yeast and Fermentation => Topic started by: Jimmy K on December 30, 2011, 02:10:36 PM

Title: Boiling starters in a flask
Post by: Jimmy K on December 30, 2011, 02:10:36 PM
I began making starters a while ago and recently got a flask. I like boiling the starter in the flask, but have a hell of a time dealing with foam from the boiling wort, which wants to shoot out all over the stove. Any suggestions on how to deal with that?
Title: Re: Boiling starters in a flask
Post by: LittleBoy on December 30, 2011, 02:27:28 PM
Used a flask for the first time last week.  Was really tentative about cracking the glass on the stove.  So I kept the heat at "medium".  Did not see much foaming but did lower the heat once I saw a decent boil.

Sure was nice to use the flask!  Now what to do with the half gallon glass jug i was using...
Title: Re: Boiling starters in a flask
Post by: Hokerer on December 30, 2011, 02:34:29 PM
Back when I used to make starters that way (use canned wort now), I too was never comfortable with boiling in the flask.  I chose to eliminate the boilover issue by boiling in a regular pan.  This also speeds up the chilling process in that I could ice-water bath chill in the pan before pouring into the flask.  Great way to kill a flask is to take it off the burner where it was boiling and plunk it in an ice-water bath the chill.
Title: Re: Boiling starters in a flask
Post by: Jimmy K on December 30, 2011, 02:37:15 PM
A lab flask shouldn't be much worry on the stove - this is what they are made for. Hot stove to ice water might be a little too much for it though.
Title: Re: Boiling starters in a flask
Post by: Pinski on December 30, 2011, 02:40:56 PM
There's a product called Ferm-Cap that comes in little 1 oz. dropper bottles. One drop in a 2L flask has kept my starters of that size from foaming out/boiling over.  Works well for preventing wort boil overs as well. Some folks have concerns about using it as it is silicone based. I've decided to only use it only as needed which for me ends up being only occasionally in starters boiled in the flask.  If I boil in a pot and monitor closely there's no need.
Title: Re: Boiling starters in a flask
Post by: Pinski on December 30, 2011, 02:50:32 PM
A lab flask shouldn't be much worry on the stove - this is what they are made for. Hot stove to ice water might be a little too much for it though.
Boiling to ice water is of more concern for me too as it would be a real bummer to break a flask and lose a starter.  I like to more gradually reduce the glass temperature by holding the flask with a oven mit and running it under hot tap water and gradually reducing the temperature of the flowing water until it's cold. Then I place the flask in a large bowl fill it with cold water. Finally displace the water in the bowl gradually with ice cubes until it's mostly ice. Has worked well for me with no crackage.
Title: Re: Boiling starters in a flask
Post by: jeffy on December 30, 2011, 04:30:25 PM
There's a product called Ferm-Cap that comes in little 1 oz. dropper bottles. One drop in a 2L flask has kept my starters of that size from foaming out/boiling over.  Works well for preventing wort boil overs as well. Some folks have concerns about using it as it is silicone based. I've decided to only use it only as needed which for me ends up being only occasionally in starters boiled in the flask.  If I boil in a pot and monitor closely there's no need.

I use this in my starters and in my boil kettle.  One or two drops is all you need.
Title: Re: Boiling starters in a flask
Post by: denny on December 30, 2011, 04:35:26 PM
Tried boiling in a flask a couple and for me it was more hassle than it was worth.  I now boil and cool in a pot, then xfer to a gal. glass jug.  No boilovers, no worry about breaking the flask, and the jug is twice the size of the flask.
Title: Re: Boiling starters in a flask
Post by: theDarkSide on December 30, 2011, 04:38:37 PM
There's a product called Ferm-Cap that comes in little 1 oz. dropper bottles. One drop in a 2L flask has kept my starters of that size from foaming out/boiling over.  Works well for preventing wort boil overs as well. Some folks have concerns about using it as it is silicone based. I've decided to only use it only as needed which for me ends up being only occasionally in starters boiled in the flask.  If I boil in a pot and monitor closely there's no need.

I use this in my starters and in my boil kettle.  One or two drops is all you need.

I use this stuff too and it works great.  And it doesn't have any affect on you, as my picture here indicates:

(http://www.badmovies.org/movies/toxicavenger/toxicavenger7.jpg)

 ;D
Title: Re: Boiling starters in a flask
Post by: tygo on December 30, 2011, 05:28:26 PM
I boil in the flask, use fermcap, and move the flask from the stove directly to a sink full of cool tap water.  Never had any problems with it but maybe I've just been lucky.  I guess that could be one of those things that works just fine until it doesn't. 

I like making them in the flask because it's quick and easy and the starter vessel is automatically sanitized.  No need to mess around with a pot and a flask and a funnel etc.
Title: Re: Boiling starters in a flask
Post by: Jimmy K on December 30, 2011, 05:41:36 PM
I like boiling in a flask because it helps me achieve my definition of awesome.
Title: Re: Boiling starters in a flask
Post by: narvin on December 30, 2011, 07:04:27 PM
Another vote for fermcap. One or two drops and you'll have no boilover issues.
Title: Re: Boiling starters in a flask
Post by: mabrungard on December 30, 2011, 10:31:08 PM
I used to boil in a flask on a glass-top stove, but that ended when I had a minor boilover and that resulted in a cracked and destroyed 4L flask.  Definitely not worth it.  I now boil in a pyrex measuring cup in a microwave oven and then transfer the cooled starter wort into the flask.  Much safer, and the potential and severity of boil overs is reduced.
Title: Re: Boiling starters in a flask
Post by: tschmidlin on December 31, 2011, 02:55:27 AM
I boil on the stove in a 4l flask with some fermcap, then put it on the stirplate to let it cool overnight, then add the yeast.  No boil overs or other problems.
Title: Re: Boiling starters in a flask
Post by: bluesman on December 31, 2011, 03:33:07 AM
I boil in a flask on the stove with fermcap then chill and move to a stirplate. Boilovers are far and few between. I have found this method to be very practical.
Title: Re: Boiling starters in a flask
Post by: morticaixavier on December 31, 2011, 06:55:23 AM
most of the time I boil my starters in a sealed pint or quart jar with a two piece lid under 15 psi.

I have boiled in a flask with no problems. I can see the benefit of a more or less sterile environment for your starter, at least until you remove the foil. but flasks are expensive and I am cheap and one gallon jugs are also cheap thus...
Title: Re: Boiling starters in a flask
Post by: kgs on January 01, 2012, 05:41:58 PM
I boil in a small saucepan and chill it quickly with an ice bath before transferring. Never had a boilover, no need for Fermcap, etc.
Title: Re: Boiling starters in a flask
Post by: wildknight on January 02, 2012, 03:06:32 PM
To avoid the boil over, simply move the flask to the side such that only 1/4 to 1/3 of the flask is receiving heat from the burner.  Then, turn the heat down.  This will allow you to create a low, rolling boil in the flask like you do in your brew kettle.  Just monitor the heat so that you maintain only enough heat to keep it rolling  Any more is unnecessary and will cause a boil over. 

One thing to be cautious of is making a starter with pilsner malt that you intend to pitch whole.  The flask, by its shape, is designed to minimize vapor loss.  The vapors collect on the side of the glass and slide back down into the base liquid.  Thus, you do not boil off any DMS from pilsner malts or extra light DME.  If after you make your starter you are going to chill and decant the liquid, then no big deal.  If I need to boil down my wort or am worried about boiling off flavors compounds out, then I will boil in a pot first, then transfer to the flask.  Then I will boil in the glass for 5 minutes just to make sure everything is sanitized.

Lab grade glassware will handle any stove and can be immediately dunked into ice baths.  The only concern is the depth of the ice bath.  Make sure it is not much deeper than the liquid inside the flask.  If you have 1-2" of wort in your flask and you dunk the flask in 6-8" of ice, then you do risk cracking the upper part of the flask that is not also in contact with liquid inside. 
Title: Re: Boiling starters in a flask
Post by: Jimmy K on January 10, 2012, 03:01:43 PM
The problem I had with simply reducing heat is that I have a ceramic cooktop stove and the elements cycle on/off at low settings. Even at vary low settings the flask would boil over when the element cycled on.

But I did get some Fermcap S last weekend and my starter last night boiled hard without foaming all over the place. Praise Jebus.
Title: Re: Boiling starters in a flask
Post by: corkybstewart on January 10, 2012, 04:19:43 PM
A lab flask shouldn't be much worry on the stove - this is what they are made for. Hot stove to ice water might be a little too much for it though.
They are designed to go from boiling to an ice bath.   I do starters when I go home for lunch, my wife hates the smell of boiling wort so I make them while she's at work.  I take them off the stove and put them directly into an ice bath so I can pitch the yeast before I go back to work.  I've been making starters this way for 10 years.
The trick is to use medium heat just until you see bubbles coming off the bottom, and then slow the heat down very low so the wort simmers for 15-20 minutes.
Title: Re: Boiling starters in a flask
Post by: wildknight on January 10, 2012, 04:49:52 PM
The problem I had with simply reducing heat is that I have a ceramic cooktop stove and the elements cycle on/off at low settings. Even at vary low settings the flask would boil over when the element cycled on.

Mine is a ceramic top too, and I don't have any problems.  Try moving it off to the side.  Also, how full is your flask?  I always limit mine to 1/2 to 2/3 full. 
Title: Re: Boiling starters in a flask
Post by: Jimmy K on January 10, 2012, 05:04:24 PM
I did move the flask to the side yesterday, about 1/2 way off, and I think that also helped. Besides less heat, it seems to help that the bubbles are all coming up one side then settling on the other - instead of rushing up on all sides of the flask.
Title: Re: Boiling starters in a flask
Post by: davidgzach on January 11, 2012, 09:35:13 PM
I'm in line with the last couple of posts.  I boil in a 5L Pyrex flask, then allow to cool a bit on the stove before transferring to an ice bath.  No problems, thanks to Pyrex....
Title: Re: Boiling starters in a flask
Post by: positiverpr on January 14, 2012, 12:18:40 PM
i've broken a 2 liter and a 6 liter flask heating on the stove. after the second one(slow learner) i just got one of those diffusers(little metal plate) that better distributes the heat and have had no problems. fermcap works great as long as you dont push the volume in the flask. i'm way to paranoid to transfer cooled wort to another container. its gotta stay in the boiling container unless im transferring in a hood and my wife ixneyed that idea. anyone working figured out how to implement that walk-in autoclave?
Title: Re: Boiling starters in a flask
Post by: tygo on January 14, 2012, 02:07:11 PM
i've broken a 2 liter and a 6 liter flask heating on the stove.

What kind of stove?  Heating on a gas stove works fine (at least for me).  Heating on an electric range is a no-no.
Title: Re: Boiling starters in a flask
Post by: davidgzach on January 14, 2012, 02:14:24 PM
I'm on electric with no problems.  But it of course has to be Pyrex....
Title: Re: Boiling starters in a flask
Post by: positiverpr on January 14, 2012, 03:29:55 PM
mines gas but instead of a solid platform it has the spiderweb design. pretty easy to see why i should have been using a defuser anyway with those concentrated hot spots.
Title: Re: Boiling starters in a flask
Post by: denny on January 14, 2012, 04:51:55 PM
I'm on electric with no problems.  But it of course has to be Pyrex....

Google "pyrex flask on electric stove" for hundreds (thousands?) of people who have broken Pyrex flasks by placing them directly on an electric stove.
Title: Re: Boiling starters in a flask
Post by: kgs on December 22, 2012, 04:21:04 PM
I used my 2L Erlenmeyer flask for the first time last night (on a gas range) and not only did it eliminate several potential contamination points, but it was fascinating to watch the wort boil. Plus there was almost nothing to clean up--no pan, no funnel. I had been using a one-gallon growler for the starter, and it had such a narrow neck it was a pain to clean.  This is one of those small "convenience" upgrades I'm glad I made.
Title: Re: Boiling starters in a flask
Post by: yso191 on December 22, 2012, 06:07:15 PM
For all 5 (!) of the starters I have done I have just taken the flask straight from the stove boiling into the sink, which I then fill with tap water, and once it is full I put ice in the sink - it takes close to an hour and its ready to pitch, though I've never timed it.

As far as boiling over, I use a bamboo skewer.  I just stick it down in the bubbles and flick it back and forth rapidly.  This breaks the bubbles up and releases the heat.  It works pretty good!

Steve
Title: Re: Boiling starters in a flask
Post by: weithman5 on December 22, 2012, 06:08:53 PM
i boil in a microwave oven in a mason jar
Title: Boiling starters in a flask
Post by: Boston Brewer on December 31, 2012, 01:40:20 PM
I've always made the starter in a pan & poured the hot wort in to the flask for chilling. The one time I boiled in a flask I received a nasty burn from stupidly swirling the wort while trying to fully dissolve the DME.
Be careful out there!
Title: Re: Boiling starters in a flask
Post by: tonyp on December 31, 2012, 05:01:03 PM
I've always made the starter in a pan & poured the hot wort in to the flask for chilling. The one time I boiled in a flask I received a nasty burn from stupidly swirling the wort while trying to fully dissolve the DME.
Be careful out there!

I did the same exact thing. My wife bought me brewing gloves a few days later and I now boil in a pot.
Title: Re: Boiling starters in a flask
Post by: mmitchem on December 31, 2012, 05:03:05 PM
I cracked a 2L flask on the range top once. So lucky it didn't shatter everywhere. I boil in a pot now.
Title: Re: Boiling starters in a flask
Post by: rjharper on December 31, 2012, 07:22:12 PM
Every time I try to use the conical flask directly it boils over. :o It's easier for me to use a pot then transfer.
Title: Re: Boiling starters in a flask
Post by: blatz on December 31, 2012, 07:54:55 PM
Yeah, boiling in a flask is like playing chicken.

Here's a trick I started doing lately when making bigger starters (maybe not so tricky to some, but it has helped me):

I boil 3/4 of the water i need directly in the flask a day before I need to make a starter. after it's boiled for 15 min or so, I cap it with foil and let it cool down on the counter and then eventually, it goes in the fridge.

The next day, I boil a super concentrated (4x) wort with a little over 1/4 of the planned volume.  Boil for fifteen minutes, then cover and let it cool down on the stove.  Once its cool enough - say about 150df or so, I pull the flask from the previous day holding just water, and direct pour the wort in and its usually right at 60df or so!  Put in a sanitized stir bar and its off and running.

Just thought that may help some of you out there.
Title: Boiling starters in a flask
Post by: Boston Brewer on January 01, 2013, 01:48:20 PM


I did the same exact thing. My wife bought me brewing gloves a few days later and I now boil in a pot.

My wife gave me gloves for Christmas!
Title: Re: Boiling starters in a flask
Post by: davidgzach on January 01, 2013, 03:53:29 PM
I'm on electric with no problems.  But it of course has to be Pyrex....

Google "pyrex flask on electric stove" for hundreds (thousands?) of people who have broken Pyrex flasks by placing them directly on an electric stove.

I sure hope I'm not jinxing myself, OK already did so:

I've been boiling on my electric range with a Bomex 5L erlenmeyer for the past year and 30-40 starters later, no prob.....

I'm sure it will crack next time now.   :-\
Title: Re: Boiling starters in a flask
Post by: tschmidlin on January 01, 2013, 11:35:56 PM
Yeah, boiling in a flask is like playing chicken.

Here's a trick I started doing lately when making bigger starters (maybe not so tricky to some, but it has helped me):

I boil 3/4 of the water i need directly in the flask a day before I need to make a starter. after it's boiled for 15 min or so, I cap it with foil and let it cool down on the counter and then eventually, it goes in the fridge.

The next day, I boil a super concentrated (4x) wort with a little over 1/4 of the planned volume.  Boil for fifteen minutes, then cover and let it cool down on the stove.  Once its cool enough - say about 150df or so, I pull the flask from the previous day holding just water, and direct pour the wort in and its usually right at 60df or so!  Put in a sanitized stir bar and its off and running.

Just thought that may help some of you out there.
I like it, I think that's a great idea.
Title: Re: Boiling starters in a flask
Post by: jeffy on January 02, 2013, 01:00:03 AM
Yeah, boiling in a flask is like playing chicken.

Here's a trick I started doing lately when making bigger starters (maybe not so tricky to some, but it has helped me):

I boil 3/4 of the water i need directly in the flask a day before I need to make a starter. after it's boiled for 15 min or so, I cap it with foil and let it cool down on the counter and then eventually, it goes in the fridge.

The next day, I boil a super concentrated (4x) wort with a little over 1/4 of the planned volume.  Boil for fifteen minutes, then cover and let it cool down on the stove.  Once its cool enough - say about 150df or so, I pull the flask from the previous day holding just water, and direct pour the wort in and its usually right at 60df or so!  Put in a sanitized stir bar and its off and running.

Just thought that may help some of you out there.
I like it, I think that's a great idea.

You could put the stir bar in the flask first.
Title: Re: Boiling starters in a flask
Post by: bboy9000 on January 02, 2013, 01:58:31 AM
Pyrex is shatter-resistant not shatter-proof.  Pyrex labware is meant to be used over a gas flame, nothing else.  Pyrex, Kimax or other borosilicate glass has a higher chance of shattering if used on electric and ceramic ranges.  Because Of this I boil in a pot on my electric range then transfer to a sanitized flask.
Title: Re: Boiling starters in a flask
Post by: Jimmy K on January 02, 2013, 02:20:00 AM
Yeah, boiling in a flask is like playing chicken.

Here's a trick I started doing lately when making bigger starters (maybe not so tricky to some, but it has helped me):

I boil 3/4 of the water i need directly in the flask a day before I need to make a starter. after it's boiled for 15 min or so, I cap it with foil and let it cool down on the counter and then eventually, it goes in the fridge.

The next day, I boil a super concentrated (4x) wort with a little over 1/4 of the planned volume.  Boil for fifteen minutes, then cover and let it cool down on the stove.  Once its cool enough - say about 150df or so, I pull the flask from the previous day holding just water, and direct pour the wort in and its usually right at 60df or so!  Put in a sanitized stir bar and its off and running.

Just thought that may help some of you out there.
I like it, I think that's a great idea.
Me too, though I don't think the two-day process is needed. You could boil some water in a flask and wort in a pot. When done, pour the hot wort into the flask and let it cool. Since it's still hot the chance of contamination is zero and the starter will be ready to innoculate sooner.
Title: Re: Boiling starters in a flask
Post by: tschmidlin on January 02, 2013, 03:57:23 AM
Me too, though I don't think the two-day process is needed. You could boil some water in a flask and wort in a pot. When done, pour the hot wort into the flask and let it cool. Since it's still hot the chance of contamination is zero and the starter will be ready to innoculate sooner.
That works too.  Although I tend to do most things at night anyway, so it would still be the next night before I pitched anything.  This was I can boil the concentrated wort, add the chilled water, and away I go.  If only sterile filtered water was cheap :)
Title: Re: Boiling starters in a flask
Post by: Joe Sr. on January 02, 2013, 04:18:28 PM
Yeah, boiling in a flask is like playing chicken.

Here's a trick I started doing lately when making bigger starters (maybe not so tricky to some, but it has helped me):

I boil 3/4 of the water i need directly in the flask a day before I need to make a starter. after it's boiled for 15 min or so, I cap it with foil and let it cool down on the counter and then eventually, it goes in the fridge.

The next day, I boil a super concentrated (4x) wort with a little over 1/4 of the planned volume.  Boil for fifteen minutes, then cover and let it cool down on the stove.  Once its cool enough - say about 150df or so, I pull the flask from the previous day holding just water, and direct pour the wort in and its usually right at 60df or so!  Put in a sanitized stir bar and its off and running.

Just thought that may help some of you out there.
I like it, I think that's a great idea.

You could put the stir bar in the flask first.

This is what I do.  I put the stir bar in the flask and add boiling water to sterilize it all.  Then I add the starter wort to the flask and pitch some yeast when it's cool enough.

Boiling in the flask scares me, though I do recall reading that the majority of problems are with electric elements in that you have an uneven distribution of heat from the element (ie. super hot where the element touches the glass).  I suppose you could use a diffuser to eliminate that problem.
Title: Re: Boiling starters in a flask
Post by: blatz on January 02, 2013, 04:26:28 PM
cool - I was always afraid the direct heat was going to melt the coating on my stir bar.  if you guys say its okay, I'll try it next time.
Title: Re: Boiling starters in a flask
Post by: Joe Sr. on January 02, 2013, 04:31:45 PM
Hasn't yet...
Title: Re: Boiling starters in a flask
Post by: davidgzach on January 02, 2013, 05:19:51 PM
Good to know about the stir bar.  I always added it right after I took the starter off the boil.  Got my finger steamed a couple of times doing this and if I do not add Fermcap, I can get a volcano.

I've been looking around the internet more on this and it seems that if you have a glass or ceramic electric stove it is not an issue.  It becomes a problem when you put the flask directly on the electric heating coils.  My glass top electric seems to distribute the heat quite well and as I have said, no problems thus far.

However, I don't want boiling wort all over the kitchen as my wife will kill me.  Thoughts on glass/ceramic stove tops versus directly on the element?

Dave
Title: Re: Boiling starters in a flask
Post by: Joe Sr. on January 02, 2013, 05:23:15 PM
Good to know about the stir bar.  I always added it right after I took the starter off the boil.  Got my finger steamed a couple of times doing this and if I do not add Fermcap, I can get a volcano.

Just to be clear, I haven't boiled the stir bar on the stove where it might be getting heated directly from the flame.

I boil water and pour it into the flask which has the stir bar in it.
Title: Re: Boiling starters in a flask
Post by: tschmidlin on January 02, 2013, 05:23:56 PM
Stir bars are usually teflon coated.  According to wikipedia, teflon has a melting point of 621F.  It will be fine in the liquid.