Blue Mold on Raspberries

[brianmcdonald]

I brewed a Kolsch from Northern Brewer. I thought raspberry would be a nice adjunct flavor. I lightly boiled 1 pound of frozen raspberries. I added this to the primary fermenter 10 days ago when the temp of the wort dropped to 70 degrees. Tonight I was going to rack to the secondary and I noticed some blue mold on the raspberries. After I transferred it the yeast bed on the bottom also had a blue tint to it. Does anyone have any Ideas what happened? Is this batch trashed?

 

[barnaclebob]

If the fruit is floating to the surface you need to punch it down every day to prevent mold. I'd try to remove the mold and rack it.

 

[brianmcdonald]

I removed the mold and racked it. I am concerned it may make someone sick. What are your thoughts on that?

 

[barnaclebob]

There is no real way of guaranteeing that it won't make someone sick but if it were me I'd drink a few bottles myself before giving it to anyone else.

 

[SmokeyMcBong]

I thought nothing grew in homebrew that makes you sick? I thought these things just made the bevvie undrinkable due to flavour. I could be wrong though

 

[fearwig]

Well, it didn't grow in homebrew, it grew on raspberries! Blue mold is not food but if the directly affected area (the raspberries) was removed you are in good shape. But you are definitely the guinea pig, right?

 

[fuelish]

No one will die....abdominal pain/nausea/vomiting/diarreah perhaps??? Truthfully, I don't know, but, yeah, if you racked it and left the mold behind, it could/should be fit for human consumption barring any off flavors. After you bottle it, sample a few to be sure before you dole it out to others. Who knows, it might be fantastic!!!

 

[fearwig]

You can eat cheese, for instance, that's had mold (blue mold being common), but you are instructed to cut a certain amount away from around the mold first. I think FDA says don't do that with softer cheeses, but meh, I have done it at home. A small amount of mold does not terrify me in food, bacteria are much scarier. The only time I've ever made myself sick was from bacteria, and let's just say I ignored some obvious hints I was doing something wrong.

Me: "This pork chop is just oxidized, right? That's just oxidation that gives it that greenish color on one side, don't you think, hon?"
Wife: "Uhh I don't think I want pork chops tonight"
Me: "You sure? I mean I can make you something else."​

Anyway, people have been getting drunk on spoiled fruit for a long time, I think you're going to be OK. Then again, me gambling with your safety is easy, isn't it?

 

[Koda]

Oooh a little mold never killed anyone. Isn't penicillin technically a mold? See it's good for you...drink up

 

[Koda]

You can eat cheese, for instance, that's had mold (blue mold being common), but you are instructed to cut a certain amount away from around the mold first. I think FDA says don't do that with softer cheeses, but meh, I have done it at home. A small amount of mold does not terrify me in food, bacteria are much scarier. The only time I've ever made myself sick was from bacteria, and let's just say I ignored some obvious hints I was doing something wrong.

Me: "This pork chop is just oxidized, right? That's just oxidation that gives it that greenish color on one side, don't you think, hon?"
Wife: "Uhh I don't think I want pork chops tonight"
Me: "You sure? I mean I can make you something else."​

I'd have eaten them too.

And probably the leftovers.

 

[Queequeg]

The health risk depends on the mould. People do eat mouldy cheese because they think some cheese has mould injected deliberately. However the mould floating around in your kitchen isn't likely the same as that used to spike cheese to begin with. That said I eat mouldy cheese, cutting off the mould like people say. Most molds are benign but some aren't.

I would probably drink it. The risk is likely to be low, but there is a risk.

 

[pablosbrewing]

I brewed a Kolsch from Northern Brewer. I thought raspberry would be a nice adjunct flavor. I lightly boiled 1 pound of frozen raspberries. I added this to the primary fermenter 10 days ago when the temp of the wort dropped to 70 degrees. Tonight I was going to rack to the secondary and I noticed some blue mold on the raspberries. After I transferred it the yeast bed on the bottom also had a blue tint to it. Does anyone have any Ideas what happened? Is this batch trashed?

Good reason to fruit in secondary. Alcohol inhibits a lot of stuff plus primary blows off less aroma and flavor.

 

[dantose]

I removed the mold and racked it. I am concerned it may make someone sick. What are your thoughts on that?

I don't know of any dangerous infections that would actually produce a drinkable beer.

 

[dantose]

The health risk depends on the mould. People do eat mouldy cheese because they think some cheese has mould injected deliberately. However the mould floating around in your kitchen isn't likely the same as that used to spike cheese to begin with. That said I eat mouldy cheese, cutting off the mould like people say. Most molds are benign but some aren't.

I would probably drink it. The risk is likely to be low, but there is a risk.

The molds that will grow are medium dependant. FOr example, sauerkraut. Sauerkraut is basically making a medium that will foster specific microorganisms and letting the environment provide them. YOu put cabbage in a salty, oxygen poor solution, and certain lactobacteria which are in the environment grow quickly and make sauerkraut. True lambic beers are a similar approach.

As far as cheeses, certain types of cheeses can harbor harmful bacteria surviving from unpasturized milk used to make them (generally only an issue in immunosuppressed people), but I'm unaware of any harmful molds that culture on hard cheeses in refrigerator temperatures.

What he's describing is probably penicillium mold, (that blue-green mold you see on moldy bread often). While some strains do produce toxins that could effect humans, by the time those build up to any detectable levels you are going to have an undrinkably poor tasting beer. The presence is likely a bigger concern simply because it indicates oxygen exposure. You should be able to scoop out the moldy parts with a sanitized spoon with no issues.