drummstikk
Well-Known Member
Hi Mindghost,
Fishing out the mold colonies may have only gotten rid of the mold fruiting bodies. Fungal growth is often invisible, and it is occurring long before we see the colored reproductive structures. Not sure about the tan colonies -- are they attached to the bottom of the glass?
Hey guys, almost every attempt on this forum to capture wild yeast has resulted in catching mold and bacteria. Even if you do have some wild yeast mixed in, it will be unusable unless you get rid of the mold.
The best way to capture wild yeast is not to just leave wort out in the air. As you all have found, this captures just about everything! You want to be selective:
The best way to do this is to get your hands on some agar and some sterile dishes. Take some wort and make a 2% (that means 2 grams in 100 mL) agar solution. Boil the wort-agar and pour enough into each plate that it just covers the bottom.
After the plates cool, take a ripe or overripe fruit directly from a tree and rub it on the agar surface. Don't touch the part of the fruit you're rubbing or the agar. Close up the plate and grow for several days. If you just open it in your home, or near a window, you're going to catch the stuff that already lives in your home -- bread mold! We all eat bread, and we all sometimes keep it until it's moldy. Our houses are bread mold factories! Go outside! Go to a fruit tree! Get your wild yeasts there.
If you get a dense lawn of growth, take a sterile loop and streak the growth onto another plate. Eventually you should pick single colonies that are opaque and creamy. Grow them up in 10 mL of sterile wort for several days and then pour off a little bit to taste. Pick the tastiest!
The next best method is instead of streaking out on agar for a pure culture, simply discourage the growth of spoilage organisms in your collection. Remove some highly-hopped beer from your fermenter when it's only partly attenuated, say 25%. Boil it to kill yeast, but remove from the heat as soon as it boils. You don't want to boil off the alcohol.
Leave this pasteurized 25% attenuated wort uncovered near wild fruit trees or bushes. The hops and alcohol will discourage the growth of bacteria and mold, but wild yeasts will do just fine. The alcohol will also attract fruit flies, which is great! They carry loads of wild yeast on their bodies, which they pick up from every ripe fruit they visit.
No more mold! This thread is starting to look like fungal pornography.
Fishing out the mold colonies may have only gotten rid of the mold fruiting bodies. Fungal growth is often invisible, and it is occurring long before we see the colored reproductive structures. Not sure about the tan colonies -- are they attached to the bottom of the glass?
Hey guys, almost every attempt on this forum to capture wild yeast has resulted in catching mold and bacteria. Even if you do have some wild yeast mixed in, it will be unusable unless you get rid of the mold.
The best way to capture wild yeast is not to just leave wort out in the air. As you all have found, this captures just about everything! You want to be selective:
The best way to do this is to get your hands on some agar and some sterile dishes. Take some wort and make a 2% (that means 2 grams in 100 mL) agar solution. Boil the wort-agar and pour enough into each plate that it just covers the bottom.
After the plates cool, take a ripe or overripe fruit directly from a tree and rub it on the agar surface. Don't touch the part of the fruit you're rubbing or the agar. Close up the plate and grow for several days. If you just open it in your home, or near a window, you're going to catch the stuff that already lives in your home -- bread mold! We all eat bread, and we all sometimes keep it until it's moldy. Our houses are bread mold factories! Go outside! Go to a fruit tree! Get your wild yeasts there.
If you get a dense lawn of growth, take a sterile loop and streak the growth onto another plate. Eventually you should pick single colonies that are opaque and creamy. Grow them up in 10 mL of sterile wort for several days and then pour off a little bit to taste. Pick the tastiest!
The next best method is instead of streaking out on agar for a pure culture, simply discourage the growth of spoilage organisms in your collection. Remove some highly-hopped beer from your fermenter when it's only partly attenuated, say 25%. Boil it to kill yeast, but remove from the heat as soon as it boils. You don't want to boil off the alcohol.
Leave this pasteurized 25% attenuated wort uncovered near wild fruit trees or bushes. The hops and alcohol will discourage the growth of bacteria and mold, but wild yeasts will do just fine. The alcohol will also attract fruit flies, which is great! They carry loads of wild yeast on their bodies, which they pick up from every ripe fruit they visit.
No more mold! This thread is starting to look like fungal pornography.