Mystery Wine Brine Scum

[cheesehead94]

I have been using a brine (50% water 50% mulled wine, then 8% salt by weight of the liquid) to wash the rind of an Asiago I have been working on. It just stays in a mason jar at room temp, and a week or two ago I started drying the Asiago rind out and not washing it anymore. So this brine has been sitting undisturbed for a little while, and today I noticed a layer or light tan colored something (bacteria perhaps) on the surface of it. It smells strong but not bad. Any ideas of what it might be?

[mikekchar]

Looks like geotrichum candidum to me (which is a yeast).

[cheesehead94]

Interesting, i've heard that word thrown around on here before. So if that's the case this brine is still safe to use?

[mikekchar]

Yeah, it's used in Camembert and some other soft cheeses.  I'm sure it's fine, but you should boil it and strain it before you use it.

[cheesehead94]

Wouldn't that also kill all of the linens I have been cultivating in there? Maybe just strain it without boiling?

[mikekchar]

It depends on if you want geotrichum in your cheeses :-)  Straining won't get rid of it.  I think I would be tempted to boil and repitch the b.linens.  If you're just holding this brine to use for another day, personally I would boil it.  For me (not an expert) the fear would be botulism developing in long term storage.  I tried to do some google searches and while a pH of under 4.4 should be good, sauerkraut, for instance is just under 5 and the salt levels prevent the botulism from growing.  Doing some searching on the internet, I haven't found a definitive answer about what levels of salt are safe.  The 50% wine with 8% salt sounds OK to me, but I'm not sure (so don't sue me if you die ;-) ).

[Lenomnom]

Pardon my necro but the photo interested me. I'm pretty sure that ain't wine yeast. What molds are there that are salt tolerant?

[cheesehead94]

Pardon my necro but the photo interested me. I'm pretty sure that ain't wine yeast. What molds are there that are salt tolerant?

Not sure, but I will say it smells more yeasty than moldy

[awakephd]

Geotrichium is at least somewhat salt tolerant.

If it were me, I'd dispose of this and start fresh the next time - but then, I usually make up only as much wash as I expect to use for a given batch of cheese.

[Lenomnom]

Got some new data on salt and wine yeast, s.cervisiae.  Salt does slow growth, but at 1.5 molar the yeast is still growing slowly. 1.5 molar NaCl translates to about 90 grams per liter of solution, or 9% w/v. So if it smells yeasty and the yeast is active, you should be able to skim the solution, stir it and see the solution go opaque with suspended sediment. It should settle again in a few hours to a day.