Making Agar Slants (Slopes) - In Pictures

weiht · Post by **weiht** » Sun Apr 15, 2012 3:24 pm

Any idea whats that growing inside the agar? It looks like fish scales inside the agar, its not on the top surface but inside the agar.

gregorach · Post by **gregorach** » Mon Apr 16, 2012 9:23 am

I can't make anything out on those photos. You can't really identify a bacteria by sight anyway, unless you're using specialised selective media. Not that it really matters... Anything other than yeast growing on or inside the agar means the same thing - infection. Ditch it. If it's growing inside the agar, chances are it's anaerobic, which is really bad news and you want to keep as far from your brewery as humanly possible.

Lars · Post by **Lars** » Fri Jun 15, 2012 6:11 pm

I made my first slants today using the procedure in 'Yeast' by Chris white. This involves autoclaving(in my case pressure cooking) the slants with the medium in them and lids on loosely, taking them out and lying them at an angle then tightening the lids fully when they've cooled. I've now got condensation in my slants. Is this a problem? What should I do?

Thanks

L

Cazamodo · Post by **Cazamodo** » Sat Jun 16, 2012 7:02 pm

I'm sure I read that if you store them upside down so it drips into the lid, them preferably using a flame quickly open each one and pour out then seal up. Or leave the lids on loosly and cover drom dust till its gone?

Saying that my slants all have. Condesation in. And its been a month since I pressure cooked them and completely forgot about them. Pleased that 20/20 still appear to be good!

Lars · Post by **Lars** » Sat Jun 16, 2012 9:53 pm

Thanx Caz, will store them upside down and pour out when innoculating them then

gregorach · Post by **gregorach** » Mon Jun 18, 2012 9:13 am

Condensation isn't really a problem - the agar medium will absorb it. I wouldn't actually advise storing them upside down... I used to do that, but what then tends to happen is that all the moisture in the air condenses out, which causes the agar to dry out, until eventually you end up with all the water at one end of the slant and a shrivelled, dried out bit of agar at the other. If you store them the right way up the agar continually re-absorbs the condensation and stays in much better condition.

barney · Post by **barney** » Tue Jun 19, 2012 9:57 pm

Slope Infection,

I have made a couple of slopes on Sunday and they went pretty well. There is a good coverage of yeast on the surface after only a few days.

The thing that's causing a bit of consternation is that one of the slopes has a large bubble on the slope surface. I have not seen this phenomenon before in about 60 or 70 slopes I have made and I am wondering if its normal?

gregorach · Post by **gregorach** » Wed Jun 20, 2012 9:11 am

barney wrote:Slope Infection,

I have made a couple of slopes on Sunday and they went pretty well. There is a good coverage of yeast on the surface after only a few days.

The thing that's causing a bit of consternation is that one of the slopes has a large bubble on the slope surface. I have not seen this phenomenon before in about 60 or 70 slopes I have made and I am wondering if its normal?

No, that's not normal. Very suspect.

Lars · Post by **Lars** » Wed Jun 20, 2012 9:15 am

gregorach wrote:Condensation isn't really a problem - the agar medium will absorb it. I wouldn't actually advise storing them upside down... I used to do that, but what then tends to happen is that all the moisture in the air condenses out, which causes the agar to dry out, until eventually you end up with all the water at one end of the slant and a shrivelled, dried out bit of agar at the other. If you store them the right way up the agar continually re-absorbs the condensation and stays in much better condition.

thanks for that, better turn them back up. Are these things ok stored at room temp indefinitely until I inoculate them?

L

gregorach · Post by **gregorach** » Wed Jun 20, 2012 9:18 am

Lars wrote:thanks for that, better turn them back up. Are these things ok stored at room temp indefinitely until I inoculate them?

L

In theory, provide they're perfectly sterile, yes. Personally I tend to refrigerate them anyway.

Lars · Post by **Lars** » Sun Aug 12, 2012 2:36 am

Ive inoculated 3 straisn now, 2 just today but the others some time ago. I inoculated them as directed from 'Yeast' dragging my loop in a zigzag motion up the slant. I cant figure out is how should my slants look? Should I have a simple thick white ridge up the slant in a zigzag shape(which some fo my slants do) or should I go for a more complete coverage of the medium? Some of mine have covered most of the medium, I think I might have had the loop fairly wet for these ones, but seem to have loads of very small or thin growth on them while others have this thick raised white zigzag up the middle. I'm guessing that when I cover a large part of the slant surface the colonies dont get the opportunity to grow too much so I end up with more of a thin film? Does this make sense? Is it bad for the yeast or does it matter?
What short of coverage should I be aiming for to get the healthiest yeast?

Thanks

L

gregorach · Post by **gregorach** » Mon Aug 13, 2012 9:32 am

I'm not sure that it makes much difference to be honest.

Lars · Post by **Lars** » Mon Aug 13, 2012 11:56 am

Thanks, I was afraid I might be creating an army of midget yeast

Cpt.Frederickson · Post by **Cpt.Frederickson** » Mon Sep 23, 2013 7:45 pm

Did my first batch of slants today, all went well. Very easy to do. Just got to innoculate a few of them and away we go!

molehill · Post by **molehill** » Sat Nov 30, 2013 4:56 pm

I find it very difficult to measure out small quantities i.e. 1, 2 or 3 gram measurements. Can anyone advice how much a gram off agar agar looks like. I have measuring spoons i.e. 1/4, 1/2 or full teaspoon measures. I would not be making up more than 10 slants at one time, probably less so if I made up 200mls of wort I would only add about 3gms of agar agar.

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