First Attempt At Slants

[Henno]

After reading Zwickel's excellent post about renewing his yeast cultures I bit the bullet and made some slants.

I boiled 1 litre of wort and got it to hit 1040 and added 5 grams of agar agar to it. The test tubes I have were a good price but a bit narrow to work in, sorry Bud. I put them in the steamer for 30 minutes and also gave them a bit of starsan before I handled them.

My trouble seemed to be the agar started to go solid before I got to the last one. I did 25. I used the eye dropper thing that came with my refractometer to fill them. There was some burping and farting when I emptied it into the tubes. Is oxidisation a worry when doing this?

My only other question is not they have gone solid in the tubes when I rotate them in my hand the wort bed is obviously loose and rolls around with the heaviest point staying on the bottom. Is this bad as well?

 

[hockadays]

Sounds good, I found in my limited two times at making slants that they rolled around inside the tube at first as well but after a few days they stuck.

 

[Zwickel]

Henno, that looks really beautiful, you did everything right.
No worries about rolling agar, as hockadays writes, after a few days the agar is thickening and gets stuck.
Also no worries about oxygen, the yeast will consume it and produce a slight pressure of CO2.

the only hint I can give is to be careful whilst inocculating, dont bring too much moisture in.

Good luck mate :icon_cheers:

 

[onescooter]

Just had a go with slants for the first time too. For me the great thing about it is that it is also good to see how sanitary you can be. I did a couple of test slants. I breathed in one to see what would happen and sure enough, you get growth on the surface. Goes to show how careful you have to be. But all good on the real ones. Very grateful for all the great info I have received on here regarding the subject.
Cheers
Scott.

 

[Franko]

here's a neat little trick if your not happy with your slant or your agar has started to go hard zap the tube with solution in the microwave for 10 secs then slant again it works a treat

Franko

 

[hockadays]

do you mean if you have inoculated with yeast and not happy, then nuke it and add more yeast when cool?

 

[Henno]

Day two and they sat outside overnight and today look to have a bit of moisture in them and the wort/agar is still rolling around in most of them.

Is the moisture bad Zwickel? I don't care if I have to ditch these and start again.

 

[MCT]

Day two and they sat outside overnight and today look to have a bit of moisture in them and the wort/agar is still rolling around in most of them.

Is the moisture bad Zwickel? I don't care if I have to ditch these and start again.

I made up my first slants today, and just have a few q's for the experts.

Firstly, I think I put too much agar in, they set within 1/2 hour, so I'm making up another batch now with a reduced amount. Is it normal for them to set so fast? (I used 2g into what was 250mL before I boiled the wort, so maybe I lost a fair bit of water to evaporation).

Secondly, the condensation from the hot media in the slants has settled into probably a couple of drops worth of water on top of the slanted media. It should be sterile, but is that normal/OK? I could probably tip it out but that would risk infection.

And thirdly, how long can you store blank slants? I spose I will find out, as they will probbly grow visible mould on them. Do you store blank slants in the fridge?

Thanks for any help.

 

[Sammus]

My slants normally set in half an hour or less. Agar only dissolves in near boiling water and then sets at 50 or 60C (cant remember which). it goes soft once you heat it up again, which can be useful.

I also have a problem with condensation though, all my plates and slants get a lot of condensation on them.

I've also had a recent problem with mould. Even before inoculating, I even left them to cool inside the autoclave to prevent them sucking in any non sterile air then immediately wrapped them in parafilm and within a week they are all covered in mould. I wash my hands thoroughly and then rub that alcohol gel stuff all over them thats meant to disinfect them (evaporates pretty quickly.. a nice cool feeling), and the side of the parafilm touching the plates is the side stuck to the paper in the box - presumable cleaner than the 'outside' part of the film. There hasn't been any siginificant difference in technique... anyone have any idea what I could be overlooking? I used to be able to leave my plates blank for weeks at room temperature and theyd stay clean...

 

[hockadays]

I found I got a few drops of condensation in each one as well, your options are don't worry about it all that happens is you get a little pool of yeast as well as on the slant and it fires like normal or before you innoculate them set up a flame to work over and unscrew the cap and quickly pour off liquid near flame so no spores get in. I've done this and not got any growth afterwards. I've only done slants twice now so I can't help you with the length of storage q. Hope this helps.

 

[Zwickel]

howdy brewers,

dont be worried about condensations and moistures in the slants at the first few days. As the slants gets older, the moisture will be adsorbed by the agar and disappears, hence the agar will swell a little bit and gets stuck. Id recommend to inocculate the slants after that has happened.
If you inocculate the slants too early, you may get yeast to the undersite of the agar, that will cause a Co2-production under the agar and keeps the agar floating.
In any case if that happened, the slants will still be good for use. As long as there are no strange germs in the slants, it just doesnt looks good, but its still usable.

Cheers :icon_cheers:

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