Erlenmeyer flask broke while heating: WTF?

Discussion in 'Homebrewing' started by MLucky, Nov 5, 2014.

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  1. MLucky

    MLucky Initiate (0) Jul 31, 2010 California

    I just had an Erlenmeyer flask crack while heating up some starter wort on the stove. WTF? Anybody else ever had this happen?

    I didn't do anything out of the ordinary. It was a 1.4L starter in a 3L flask. I put it on the burner on the stove and it was just about at the point of boiling when I heard a kind of muffled pop. I went over to see what had caused the sound and realized the flask had cracked and was leaking just a little bit out of bottom. I took it off the stove and let it cool, and eventually poured out the starter. Good thing I was sitting right there or I might've had a pretty serious mess on my hands. As it is, I'm just kind of puzzled and ticked off. What the hell? I can only guess that maybe I cracked it somehow and didn't notice, because I've boiled this thing many times before without problems.
  2. Johntomk

    Johntomk Initiate (199) Jul 22, 2014 Tennessee

    What brand was it? If it wasn't Pyrex brand, then that may be your answer.
    tkdchampxi and inchrisin like this.
  3. inchrisin

    inchrisin Zealot (571) Sep 25, 2008 Indiana

    You're lucky you didn't take a shard of glass to the face, honestly. I would assume that you'd be better off trying to heat with an open flame of some sort, but as said above ^^^ not all glass is tempered the same and the strengths vary.

    As for me, I'll heat wort and cool wort in a pot. I'll use a sink full of cold water and ice cubes to cool the wort quickly. I'll use StarSan on the flask, the foil on top, and the stir bar. I'll add the wort when it's fairly cool to the touch and center the magnet. I place a paper towel between the stirplate and the flask anymore. It keeps noise down and you never know when yeast is going to get unruly and try to get out.
    #3 inchrisin, Nov 5, 2014
    Last edited: Nov 5, 2014
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  4. Johntomk

    Johntomk Initiate (199) Jul 22, 2014 Tennessee

    To elaborate a little....even if your flask was borosilicate, it may not be high quality. Bomex is typically a cheap alternative to Pyrex. Although they are generally the same type of glass, the quality is much different. I've found, that in lab, Pyrex is much more reliable. The cheaper glassware is more prone to tiny scratches that can cause it to shatter when subjected to a sudden temperature change. Don't even get me started with the cookware they call pyrex (it's actually just soda lime glass). Check out science direct out of Colorado. They sell pyrex brand, and it's definitely worth buying over the cheaper stuff.
    nickfl and billandsuz like this.
  5. marc77

    marc77 Poo-Bah (2,044) May 25, 2001 California

    Have to ask-- Electric or gas stove? If the former a wire trivet is recommended. I use a 5L "Bomex" with on a electric stove using a trivet. Without it there's far too much stress especially with cheaper glass.
    sarcastro likes this.
  6. Tebuken

    Tebuken Initiate (0) Jun 6, 2009 Argentina

    Stupid question, this borosilicate glass(I have a Pirex Erlenmeyer) allows to be suddenly cooled after boiling or it behaves like regular glass?
  7. ronobvious2

    ronobvious2 Initiate (0) Aug 24, 2010 Tennessee

    I'm pretty sure you're not supposed to be using an electric stove. Flame = OK, electric = not OK. Just searched and found this.
    LuskusDelph and OldSock like this.
  8. tkdchampxi

    tkdchampxi Initiate (0) Oct 19, 2010 New Jersey

    Even within the Pyrex brand, there are different levels of quality to the glass that makes it more resistant to high temperatures. However, even Pyrex can develop small micro-cracks over time due to exposure to extreme temperature swings. Sometimes these hidden flaws in an old glass apparatus can cause it to crack later on, even though it is not exposed to an extreme temperature swing at that time.

  9. DrewBeechum

    DrewBeechum Meyvn (1,044) Mar 15, 2003 California

    This will happen. It's the nature of heat resistant glassware. I had a 5L crack along the bottom on me and that was it. Flasks are cool and what not, but they will eventually fail and usually at the worst time. That's when I turned around and started pressure canning my starter wort - mason jars are cheap! And these days a large pressure canner can be had for ~$80-90.

    Plus it's a fuckton faster to prepare a starter that way.

    The Starter Made Easy
    ryane and Naugled like this.
  10. MLucky

    MLucky Initiate (0) Jul 31, 2010 California

    Thanks for all the replies. Just to answer a couple of the questions posed:

    The flask does not have a brand name on it. Checking the seller's website, they don't give a brand, but they do note (inconspicuously, at the bottom of the page) that it is a "student grade" flask. It is borosilicate glass. It was used on a gas burner.

    Given what others have written here, it sounds like these flasks are much more prone to failure than is generally believed. I think in the future I'll use the "double boiler" method, and I would recommend that to others. Thanks again.
  11. spartan1979

    spartan1979 Disciple (302) Dec 29, 2005 Missouri

    I had an off brand flask that cracked the very first time I heated it. No more off brands for me. Just Pyrex and Kimax.
  12. GreenKrusty101

    GreenKrusty101 Initiate (0) Dec 4, 2008 Nevada

    I think many people just like saying, "Erlenmeyer" conjures up images of white lab coats and mad scientists/homebrewers. :slight_smile:
    PortLargo likes this.
  13. hopfenunmaltz

    hopfenunmaltz Poo-Bah (1,911) Jun 8, 2005 Michigan

    That is why they make round boiling flasks.

    Didn't anyone learn from Walter White?
    paulys55, LuskusDelph and VikeMan like this.
  14. MLucky

    MLucky Initiate (0) Jul 31, 2010 California

    I thought only Agent Schrader was a homebrewer.
    BrewerB likes this.
  15. ZDSmith87

    ZDSmith87 Initiate (0) Jul 18, 2014 Massachusetts

    Speaking of this, I just got a real deal stir plate (I work for a biotech company) and wasn't sure what temperature anyone keeps theirs at when they are doing a yeast starter?

  16. PSU_Mike

    PSU_Mike Champion (865) Sep 6, 2013 Pennsylvania

    Or Heisenberg.
    GreenKrusty101 likes this.
  17. WickedSluggy

    WickedSluggy Disciple (381) Nov 21, 2008 Texas

    I make big starters. I typically use the big-ass 5000ml flasks (or an actual carboy when making lagers). I buy the cheapo flasks ones from homebrew suppliers, and they aren't borosilicate glass (Lab grade flasks are very expensive). I have used the same procedure for many years and haven't had any problems since adopting it. Basically a double-boiler technique.

    Put the water and extract in the flask.
    Put the flask in a large kettle.
    Add water to the kettle to about the same level as the water in the flask.
    Put some aluminum foil over the flask opening and lid on kettle.
    Heat large kettle to a boil.
    "Steam" starter flask for about 30 minutes or so (measure temperature of starter liquid to ensure it's sanitized).

    Once sanitized, if you want, you can slowly add water/ice to the kettle to reduce temperature of starter to fermentation temperatures.
  18. MLucky

    MLucky Initiate (0) Jul 31, 2010 California

    I think standard operating procedure is to ferment starters of all kinds at room temperature. You're growing yeast, not making beer, so roughly 70F is fine in most cases.

    If you're not planning to decant the starter wort, I could see doing a controlled temperature starter, especially if it was a particularly large one. But I think most of us just do room temp.
  19. ronobvious2

    ronobvious2 Initiate (0) Aug 24, 2010 Tennessee

    Given a starter has a much smaller volume of fluid and constant or near-constant agitation, is there some reason you'd need to bother with temperature control, given an average room temp of 70F?
  20. minderbender

    minderbender Initiate (0) Jan 18, 2009 New York

    My understanding is that borosilicate glass can be rapidly cooled (for instance, taking it directly from the stovetop and partially submerging it in cold water) without breaking, unlike normal glass. Obviously, as the OP learned, even borosilicate glass is not indestructible, but at least it is intended to be used in this way.
  21. billandsuz

    billandsuz Zealot (512) Sep 1, 2004 New York

    By real deal stir plate you mean lab quality, with the ability to adjust the temperature of the plate I assume.
    Leave the heat off. We are making yeast here. A fancy bug from a bio-tech research facility would probably like to have some warmth, but 70 or so is just fine for our bugs.
  22. ZDSmith87

    ZDSmith87 Initiate (0) Jul 18, 2014 Massachusetts

    Yes, I mean lab quality, up around $2,000 quality, that I got as a very generous gift. But without a user manual!
  23. MLucky

    MLucky Initiate (0) Jul 31, 2010 California

    In the vast majority of cases, no. Room temp is fine. Sorry if that wasn't clear above.
  24. Bwhamon

    Bwhamon Initiate (0) Aug 29, 2014 Kentucky

    I almost bought a couple of generic Erlenmeyer flasks from Amazon. Glad I did not after reading this. Thanks for the post OP.
  25. Ilanko

    Ilanko Initiate (0) Aug 3, 2012 New York

    I have blow a Pyrex measuring cup before and it's a big mess. From that point on I switch to flasks and heat it in a stock pot filled with water as mediator.
    In large starter volume I use my trusted pressure cooker to boil the starter wort.
    The pressure cooker reduce time period need to sensitize the wort.
  26. VikeMan

    VikeMan Poo-Bah (2,036) Jul 12, 2009 Pennsylvania

    No. Although some folks do their Lager starters at more lager fermermention-like temps. I don't normally do that myself, but I wouldn't say they are wrong, either.
  27. ronobvious2

    ronobvious2 Initiate (0) Aug 24, 2010 Tennessee

    Given that, is there any real reason to decant the wort once the starter is done?
  28. AlCaponeJunior

    AlCaponeJunior Poo-Bah (2,671) May 21, 2010 Texas

    Never particularly trusted glass containers on the stove, no matter what the brand. I've never had stainless steel break on the stove when making starters. :rolling_eyes:

    Use a regular pot with a good lid. Heat, boil, cool with lid on. Add to sanitized flask, put on stir plate (or whatever you do with it at that point).

    You'll Never have that problem again. :sunglasses:
  29. WickedSluggy

    WickedSluggy Disciple (381) Nov 21, 2008 Texas

    I always decant the starter liquid. It's disgusting stuff (very oxidized). The idea of pouring two or three liters of it into my beer kinda triggers my gag reflex. But I typically make bigger starters than a lot of homebrewers.
    tngolfer likes this.
  30. VikeMan

    VikeMan Poo-Bah (2,036) Jul 12, 2009 Pennsylvania

    Taste your finished starter sometime and decide for yourself. I decant. But it's funny how many people will painstakingly develop a recipe, and then dump a liter or more of spent starter into their 5 gallon batch.
  31. ronobvious2

    ronobvious2 Initiate (0) Aug 24, 2010 Tennessee

    OK, this makes sense.
  32. ryane

    ryane Initiate (0) Nov 21, 2007 Washington

    This is all I do, although Ive switched from mason jars to wide mouth nalgene bottles = shatterproof, go ahead ask me why I like them.......
    Slatetank likes this.
  33. FATC1TY

    FATC1TY Champion (891) Feb 12, 2012 Georgia

    I'm looking to probably start pressure canning wort as well. Seems easy enough to do so, put them in a box, and save them for when I need a starter. Pour into the flask, add the yeast, turn on the plate.

    Do you add nutrient to the DME and water in the jars when you can?
  34. GreenKrusty101

    GreenKrusty101 Initiate (0) Dec 4, 2008 Nevada

    I have no problem using the entire starter if NOT using a stir plate and keeping the temps reasonable.
  35. DrewBeechum

    DrewBeechum Meyvn (1,044) Mar 15, 2003 California

    I can only imagine - which bottles are you using now?

    Yup, it's an imprecise amount of a "pinch" :slight_smile: But regardless, there's always nutrient onboarded into the jars.
  36. ryane

    ryane Initiate (0) Nov 21, 2007 Washington

    At ~7$/bottle they aren't exactly dirt cheap, but neither was the autoclave I use them in :slight_smile:

    I have 10 of them and actually only fill them with extra wort left over from brewing (I squeeze out the hops and then sterilize in the autoclave). I havent had to boil or cool wort to make a starter in years, and it has been awesome!
    Scumbag81 likes this.
  37. Scumbag81

    Scumbag81 Initiate (82) Sep 10, 2014 California

    Ditto. Autoclaving your starters is the way to go. Been three years since I've done anything but either sterilize wort left over from a batch or throw DME and water together on a hot stir plate before autoclaving.
  38. firstthenlast

    firstthenlast Initiate (85) Nov 25, 2013 Massachusetts

    electric stove breaks them...
  39. BumpkinBrewer

    BumpkinBrewer Disciple (329) Jan 6, 2010 Massachusetts

    Anyone heat their flask with a glass top electric stove?
    My first attempt I used a double boiler but the flask was jittering/clanking as the water around it boiled so I pulled it out and put it right on the burner. I was successful but don't want to push my luck next time.
  40. minderbender

    minderbender Initiate (0) Jan 18, 2009 New York

    In case it's useful for anyone, @OldSock has recently written a post about using a pressure cooker to can starter wort. It seems like a good investment if it's something you do often enough. Just make sure you know what you are doing in terms of ensuring that the wort is sterile.
    OldSock likes this.
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