How to obtain hot break free Culture Slants ?

[Blue-Frog]

I tried to get this question answered in "Slanting"...
but activity seems low there now... so I am reforming the question:

I made several slants; everything went well...
but I got a lot of hot break protein crud in the slants...

How can I produce clean, crud free slants?

(How do you get clean, crud free slants?)


What is the best, minimum boil time ?
Agar addition is best before or after hot break?
How do you filter to remove hot break?

 

[Yooper]

When you make a slant, aren't you using a sterilized loop with just yeast (no wort)?

 

[jbaysurfer]

Yooper, the yeast is cultured on a medium inside of that slant. It's a combination of wort and agar.

I boil the dme solution until I get a good hot break. I then turn down the heat and add the agar, then bring to a boil again after that. I don't get crystal clear slants, but they're pretty clean in general. When I shut the heat down usually the proteins precip out to the bottom while the Agar slowly thickens.

 

[jbaysurfer]

OP, if you want crystal clear slants though, you could add whirlfloc, boil to hot break. Let cool to precipitation of the proteins, siphon off the clear wort and leave the hot break behind, add the agar, and reboil.

 

[Yooper]

Yooper, the yeast is cultured on a medium inside of that slant. It's a combination of wort and agar.

I boil the dme solution until I get a good hot break. I then turn down the heat and add the agar, then bring to a boil again after that. I don't get crystal clear slants, but they're pretty clean in general. When I shut the heat down usually the proteins precip out to the bottom while the Agar slowly thickens.

Oh, I thought he was making a starter and dividing it up in the agar/culture medium.

I don't see any issue with a little hot or cold break in the slant, and I don't know how to keep it all out that way.

 

[jbaysurfer]

Oh, I thought he was making a starter and dividing it up in the agar/culture medium.

I don't see any issue with a little hot or cold break in the slant, and I don't know how to keep it all out that way.

Yeah, I don't either really. Usually if you're using a slant instead of a plate it's because you already have a really clean sample to preserve, and then you pitch the whole thing into your starter when you're making it, so it's not like you need to see the colonies all that well. Just well enough to confirm they look healthy before you pitch them into your starter.

 

[tally350z]

I have tried it multiple ways and every time I have autoclaved my slants, the hot break forms. It will settle out and not cause any issues.

In order to make proper slants without an autoclave(pressure cooker). You need to do a process called Tyndallization, where you boil for 15-20 minutes a day over the span of three days. If you just try to boil the media as you normally would for a starter,than you are risking a great chance for contamination. You want to add the agar before you get to a boil if your using a stock pot to make sure it is completely dissolved.

 

[Blue-Frog]

I have tried it multiple ways and every time I have autoclaved my slants, the hot break forms. It will settle out and not cause any issues.

I am not sure when my hot break formed, but I did not feel uneasy until after the slants had set.

My hot break didn't settle out but was sort of marbled throughout the gel

 

[tally350z]

can you post a picture? Can you also put your process up

 

[Blue-Frog]

Yooper, the yeast is cultured on a medium inside of that slant. It's a combination of wort and agar.

I boil the dme solution until I get a good hot break. I then turn down the heat and add the agar, then bring to a boil again after that. I don't get crystal clear slants, but they're pretty clean in general. When I shut the heat down usually the proteins precip out to the bottom while the Agar slowly thickens.

Do you then decant off the bottom proteins
before going into tubes and ultimately into your autoclave device?

(humm, do you ever get a second hot break after autoclaving?)

Perhaps I just went too fast...

How much time are you taking to get to the point where you are ready to autoclave?
More than 15~20'?

I might have had ants in my pants... adding it all then boiling!

 

[Hermit]

It is generally accepted that hot break is good for yeast health so why try so hard to get rid of it?

 

[Blue-Frog]

can you post a picture? Can you also put your process up

I am not where the slants are now plus they have growth, so I am not sure how much would be visable now if I take them out of cold storage, but I may try and see.

Process? As I wrote under the "slanting" post, what happened is kind of a blur, but The process that I followed is one that I wrote out before hand, so in theory yes. In practice it depends; I am in the slow process of moving and not everything is where it is supposed to be.

from memory, I calc. desired vol, added 10% for boil off and mishaps, 10% of that vol = gm of DME added
to prewarmed water, agar sprinkled on and allowed to moisten, heat raised to a boil with stirring then 1 or 2 microspoons of yeast nut stirred in. IH Heat was used to heat the bottom half of a trad. (flame top) 300 ml Italian Espresso pot I was using for the boil.

I may have tried to coffee filter the sol, & that may not have worked so I might have tea strainered and or filled the tubes then autoclaved and slanted.

 

[Blue-Frog]

It is generally accepted that hot break is good for yeast health so why try so hard to get rid of it?

The short answer is
"they were not nice to look at".


The long answer is...
I thought it was cold break that was felt good by some...
but yes, that might be a good point if the lipids are helping;
infact my question (under yeast slanting) was if it was OK to just leave it...

 

[jbaysurfer]

Do you then decant off the bottom proteins
before going into tubes and ultimately into your autoclave device?

(humm, do you ever get a second hot break after autoclaving?)

Perhaps I just went too fast...

How much time are you taking to get to the point where you are ready to autoclave?
More than 15~20'?

I might have had ants in my pants... adding it all then boiling!

Yes, I get a second hot break when autoclaving. If the first hot break is strong enough though, it's a very mild hot break in the pressure cooker. I tend to do full 15-20 minute aggressive boils for my starters, so the break is usually quite healthy.

I would say I do a "rough decant" off the hot break proteins because they mostly settle while cooling and I generally try to pour off the top of them, but some still get in there. Usually it's more then 20' for sure. I take my time letting it cool while getting the rest of the kid ready for autoclaving.

 

[Blue-Frog]

OK thanks.

That was probably the problem... I wasn't planning on having a hot break rest... I just wanted to plug & play, mix & pour

I'll be mixing up another batch soon so I will set more time aside for the process.

& take some pix too.

 

[melchermatt]

What I do is use wort that has been autoclaved/pressure cooked. I make jars of starter wort and use one of the jars from a previous batch.

I carefully take whatever amount I need to make my slants, mix in the agur and heat accordingly. Once measured into the tubes, you can lay them at an angle and you have slants. I have also put them through the pressure cooker again with no problem.

They are crystal clear because the protiens and break that formed when the wort was canned can easily be avoided.