Yeast Sarter in Flask - Lesson Learned the Hard Way

[hcfd918]

I have made many yeast starters on the kitchen stove in a regular pot and using a growler to grow my yeast in. Always wanting to improve my process, I purchased a stir plate and a couple of 2000 ml flasks. This seemed like the way to go because you could heat the flask and never have to transfer the cooled liquid before adding the yeast. Not to mention the added yeast growth. So I decide to use my propane camping stove instead of the electric range inside to make my first starter in the flask. After getting the water to boil I went to add my 5 ounces of DME in the 1.5 liter of liquid. Now in hindsight I'm not sure why I never saw this coming, but I was rushing thing a bit to go meet some friends for a playoff game. As I dump the DME into the flask using a paper funnel, It comes shooting out immediately like a volcano going all over my hand and down my leg. Minor burns and a very large mess is what resulted from my lack of thinking this thing out better. I have read quite a bit about starters and haven't really seen this mentioned before or if I did it apparently didn't stick. As dumb as this makes me feel I am posting this to maybe help save someone else a burnt hand and very large mess. It was a good thing I used the camping stove in the garage! My second attempt went quite well as I heated the water to almost boiling, removed the flask from heat, added and mixed the DME and then placed it back on the heat. The brew day went great which made it all better. Hopefully this will help someone in their brewing journey.

 

[HighGrav]

I was expecting to read about the flask breaking when it was heated but the volcano flask was a great twist.

I also learned the hard way to take boiling water off the heat before adding anything. I was boiling some sugar, water, and lemon juice to make a batch of Skeeter Pee. I went to add about a tsp of yeast energizer and nutrient and as soon as it hit the boil, it foamed up all over the stove. Talk about a sticky mess.

 

[Johnnyhitch1]

I was expecting to read about the flask breaking when it was heated but the volcano flask was a great twist.

I thought the same exact thing lol

 

[cooper]

yeah, those flasks suck when it comes to making the starter. I just make the starter on the stove and transfer it to the sanatized flask. Too scared of the glas breaking from the hot liquid or the boil over getting out of hand.

 

[Satisfaction]

Erlenmeyer flasks can be dangerous when boiling substances that will foam, as you just discovered.

A pinch of hydrophobic silica and a drop of food grade silicone oil will take care of the foaming problem, or the antifoam stuff they sell at the LHBS.

Another trick is to put the flask half on and off the burner. This allows the boil to take place and an area for the foam to subside.

 

[Token]

I thought the same exact thing lol

Heh, heh. Me too!

 

[hcfd918]

Whats funny is I put quite a bit of thought into not breaking the flask which is why I ended up doing it in the garage on a propane stove. I heated it up slowly (which still didn't take long) as to not change the temp. of the glass to rapidly. Didn't really consider that the physics of the whole process would change in the confinement of a flask. It was definitely the stickiest mess I've had. At any rate I am laughing at myself now......not so much when it happened though.lol

 

[Cider123]

Short answer: If you want to heat it that way, you must have something in the water like the stir rod or a boiling chip. This will allow the water to boil when boiling temp is reached. This happens to folks a lot when they heat in a clean, unscratched flask in the microwave.

Long answer: Well, do you really want to know? Unless small air bubbles already exist in your liquid or on the surface of the flask, the bubbles that come from boiling cannot form and overcome the force of surface tension. So water does not boil at 212 (give or take) and we think it's not "hot" enough yet. The water goes above 212 (superheats). Then when you drop something in it or mix it, then blammo, boiling with a vengance and at a higher temp. Sorry, its the science teacher in me (and BTW I've done it too)

 

[hcfd918]

Erlenmeyer flasks can be dangerous when boiling substances that will foam, as you just discovered.

A pinch of hydrophobic silica and a drop of food grade silicone oil will take care of the foaming problem, or the antifoam stuff they sell at the LHBS.

Another trick is to put the flask half on and off the burner. This allows the boil to take place and an area for the foam to subside.

Thanks for the info. I will try that and see how it works.

 

[hcfd918]

Short answer: If you want to heat it that way, you must have something in the water like the stir rod or a boiling chip. This will allow the water to boil when boiling temp is reached. This happens to folks a lot when they heat in a clean, unscratched flask in the microwave.

Long answer: Well, do you really want to know? Unless small air bubbles already exist in your liquid or on the surface of the flask, the bubbles that come from boiling cannot form and overcome the force of surface tension. So water does not boil at 212 (give or take) and we think it's not "hot" enough yet. The water goes above 212 (superheats). Then when you drop something in it or mix it, then blammo, boiling with a vengance and at a higher temp. Sorry, its the science teacher in me (and BTW I've done it too)

I knew someone would be able to explain it. Great info! I didn't figure I was the only one this ever happened to. It all makes perfect sense now. Thanks

 

[william_shakes_beer]

Short answer: If you want to heat it that way, you must have something in the water like the stir rod or a boiling chip. This will allow the water to boil when boiling temp is reached. This happens to folks a lot when they heat in a clean, unscratched flask in the microwave.

Long answer: Well, do you really want to know? Unless small air bubbles already exist in your liquid or on the surface of the flask, the bubbles that come from boiling cannot form and overcome the force of surface tension. So water does not boil at 212 (give or take) and we think it's not "hot" enough yet. The water goes above 212 (superheats). Then when you drop something in it or mix it, then blammo, boiling with a vengance and at a higher temp. Sorry, its the science teacher in me (and BTW I've done it too)

Is this akin to lack of nucleation sites on the bottom of the flask? Is an "old" flask safer? IE does it more reliably boil promptly at 212F?

I always boil and cool in a saucepan and transfer to the flask after pitching my yeast, so this is more of a scholarly question.

 

[Satisfaction]

I knew someone would be able to explain it. Great info! I didn't figure I was the only one this ever happened to. It all makes perfect sense now. Thanks

Very good explaination by our resident science teacher

I add the DME at the beginning because its hard as heck to get all the DME in there with steam rehydrating it and turning into a sticky gumball.

 

[Cider123]

Is this akin to lack of nucleation sites on the bottom of the flask? Is an "old" flask safer? IE does it more reliably boil promptly at 212F?

I always boil and cool in a saucepan and transfer to the flask after pitching my yeast, so this is more of a scholarly question.

Exactly, An old flask that has scrapes in it has much less chance of this happening because those sites form pockets of air to form bubbles.

This doesn't only happen with pure water. You can have this happen with dissolved solutions too. The times I have done it include heating up agar broths in the lab.

 

[terrapinj]

def learned this the hard way on the stove top - what a miserable mess to clean up

I now just mix my dme with the water before i start heating and use a drop or 2 of fermcap and haven't had any repeat issues (knock on wood)

 

[spenghali]

Add the DME to the COLD water before you even start the boiling. It won't clump, it actually mixes better in cold than hot water.

 

[hcfd918]

All good stuff here. I did wonder about adding the DME beforehand but was worried I'd end up with a big DME ball that wouldn't dissolve. I will give that a shot next time before I heat it up. Will the anti-foaming agents like fermcap or any others cause a decrease in head retention of the finished beer?

 

[kh54s10]

I warm the water a bit but not enough to make steam. I then take the vessel off the burner and stir in the DME. It dissolves easily and does not stick to what I am pouring it out of. I then raise to boiling temps. I started out boilng it in the flask but now boil in a pot and transfer to the flask because it is so much easier to stir in the DME.

 

[worxman02]

I had problems boiling in the flask when I first started doing it. There are several tricks that I figured out after the first couple times.

1. Add the DME to the flask BEFORE adding any water. This prevents the DME from sticking to every surface of the flask and allows you to use the water to wash down any stuck DME.

2. Use anti-foam like Fermcap-S or infant anti-gas drops.

3. Don't make a starter close to the total volume of your flask if you can. Making a 2L starter in a 2L flask will make it boil over easier because the liquid level is now near the narrow portion of the flask. This also helps prevent the krausen from blowing over, which recently happened to me with a very active WLP001 Cal Ale 2L starter I made.

4. Make sure you have a spoon that can fit down into your flask. I discovered this after starting the boil and luckily my spoon was plastic so I could shave it down enough to fit inside.

 

[terrapinj]

All good stuff here. I did wonder about adding the DME beforehand but was worried I'd end up with a big DME ball that wouldn't dissolve. I will give that a shot next time before I heat it up. Will the anti-foaming agents like fermcap or any others cause a decrease in head retention of the finished beer?

i've never had problems when used in the proper amount - I believe some people even add to their fermentation vessel to prevent blowoff but i've never tried using it post boil

 

[hcfd918]

Thanks for all the suggestions. I definitely don't care to repeat this mishap again!

 

[beergolf]

Add the DME first, then add the water, shake it up, the put it on the burner. A drop or two of fermcap will do wonders to keep the foaming down.

Adding the DME first keps it from clumping and it is easy to shake it mix it up.

 

[hcfd918]

Well I made one without a mess thanks to all the advice. Added the DME first and didn't have any problem at all. I still have to pick up some fermcap and give that a try next time. Unfortunately I didn't have any yet so I just watch the heat and moved it off the burner a bit. I did however pitch my stir bar with the yeast. Lol......I'll get the hang of this flask and stir plate stuff eventually. Oh the fun of home brewing.

 

[BigRedHopHead]

Ditto, happened to me too. I have now do all my starters in a 8qt stock pot on the stove. Then transfer over to the flask using a funnel. Sure there are more parts that could be contaminated, but that is what Starsan is for. I spray the **** out of everything!

 

[hcfd918]

That is a fact, Starsan is our friend. I have yet to have an infected batch.

 

[william_shakes_beer]

I did however pitch my stir bar with the yeast. Lol......I'll get the hang of this flask and stir plate stuff eventually. Oh the fun of home brewing.

Yeah, I did that too on my first bartch. When I went to the LHBS to get grains for my next batch, I picked up 2 more stir bars. Now I have 3 and haven't pitched one since