Author Topic: How do you use Penicillium Roqueforti?  (Read 9076 times)

Fantastical

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How do you use Penicillium Roqueforti?
« on: October 20, 2011, 06:49:09 PM »
Hey all,

I just signed up on here and I am getting into cheese making. I am an avid cheese lover and I enjoy every single cheese out there! I've already made some mozzarella and it turned out great!

However, due to my love for stronger cheeses, I would like to make a blue cheese.

I have done some research but I have been unable to find any solid info on how to use a culture.

The things I am unsure about are:

1. How much of a culture do you need per batch approximately?
2. How much of a culture do you buy at once and how many batches is an amount good for?
3. I've seen the term starter used. Is this a way of propagating the culture create more to use? How does this work exactly?

I am looking at buying some cultures from http://glengarrycheesemaking.on.ca/starterscultures.htm but the list of cultures confuses me. hehe...

Thanks for your help!

Matt

linuxboy

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Re: How do you use Penicillium Roqueforti?
« Reply #1 on: October 20, 2011, 07:03:29 PM »
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How much of a culture do you need per batch approximately?
Which culture, p roqueforti? Depends on the strength you need in the final cheese, and method of inoculation, but generally, you need about 2.0 x 10^9 - 4.0 x 10^9 spores, with a germination rate of at least 25% per 1,000 liters of milk. In practice, this translates to "not much" when using for small batches. And by not much, I mean something like 1/64 tsp per gallon.

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2. How much of a culture do you buy at once and how many batches is an amount good for?
Again, which culture? p roqueforti? Well, that's up to you. How many batches are you going to do before the culture degrades to the point of not being usable? If you are making 1,000 liters every day, you buy enough to last you however long before the culture expires. I guess I'm not really understanding your question. You buy the amount necessary to use it up before it goes bad based on your batch size and make frequency.

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3. I've seen the term starter used. Is this a way of propagating the culture create more to use? How does this work exactly?
Yes, please search the forum for the word propagate and propagation. I, Sailor, and others have covered this in multiple threads.

Welcome :)

Fantastical

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Re: How do you use Penicillium Roqueforti?
« Reply #2 on: October 20, 2011, 07:23:57 PM »
Thanks Linux! That really sets me in the right direction! Much appreciated!!

Matt

linuxboy

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Re: How do you use Penicillium Roqueforti?
« Reply #3 on: October 20, 2011, 08:20:19 PM »
Post if you're still stuck, but there's lots of very clear info in past threads. If you don't get the whole spore density issue, that's okay. Do the best you can. I posted the info because it was the absolute 100% correct information. Say, someone wanted to use liquid hypotonic solution or in-lab propagated p roqueforti and read this thread in the future. Then the amount would be different, of course, but the core concern is the number of spores that will germinate after addition, so I posted that number. Happy learning :)

Offline Aris

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Re: How do you use Penicillium Roqueforti?
« Reply #4 on: October 23, 2011, 01:51:42 PM »
You can grow your own P roqueforti culture fyi. Lace a plain bread (much better if you bake your own) with the moldiest part of a store bought blue cheese and store it in a tupperware. When its really moldy, grind the moldy crumbs into powder using a coffee grinder and use that to inoculate the milk. As for the quantity of the culture to use, 1/8 teaspoon powder would suffice per gallon.

I've attached a photo as an example.  To the left a blue cheese inoculated with homemade culture and to the right, my homemade bread as a growing medium for the P. Roqueforti.

gstone

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Re: How do you use Penicillium Roqueforti?
« Reply #5 on: October 23, 2011, 08:08:27 PM »
Brilliant!  Thanks Aris, that'll save me a few bucks.  I see holes in your bread, what's your method for inoculating the bread?  My inclination would be to take the mold bits from the cheese, mix them in a blender with sterile water, and use that water to inject the bread with.  Or do you just stick the mold directly into the bread?

Offline Aris

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Re: How do you use Penicillium Roqueforti?
« Reply #6 on: October 24, 2011, 12:08:39 AM »
Simply smear a small piece of the moldiest part of a blue cheese onto a bread. Since my bread is very thick, i cut it in half and smeared the blue cheese in the middle. I also pierced it so the blue mold will grow in the thickest part of the bread, not just the outside. Iirc that bread is 25 days old. As long as you can see a good mold growth on the bread, you can scrape that and use that immediately to inoculate the milk. Remember to use plain bread, i believe store bought bread have anti fungal additives so its better if you can make your own bread.

gstone

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Re: How do you use Penicillium Roqueforti?
« Reply #7 on: October 24, 2011, 07:47:23 AM »
Thanks.  I often make my own bread, so that's my simplest and safest option. Cheers!

Do you think this method would work with Camembert and Brie molds as well?

Offline Aris

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Re: How do you use Penicillium Roqueforti?
« Reply #8 on: October 24, 2011, 09:47:01 AM »
I'm not sure but I'm contemplating on trying. First, i have to get a "real" camembert or bire which is tough to get in the Philippines. I think non aoc branded brie or camembert doesn't have an active mold culture.

Offline fied

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Re: How do you use Penicillium Roqueforti?
« Reply #9 on: October 24, 2011, 11:06:19 AM »
Aris, I don't know if it helps, but I age the moulded bread to 45 days and I make/use a dryish bread with a high proportion of rye flour in it. It can be done the Roquefort way, by cutting a slit in the side of the flattish bread and inserting the blue mould, then leaving it for the 45 days in a designated area. That way, all the mould develops on the inside of he bread, which can then be crumbed. I suppose the thinking is that having the internal mould only stops a lot of the spores from floating about where they're not wanted.

darius

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Re: How do you use Penicillium Roqueforti?
« Reply #10 on: October 24, 2011, 04:39:05 PM »
What kind of environment does the bread need to grow the culture (temp, humidity, etc.)

linuxboy

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Re: How do you use Penicillium Roqueforti?
« Reply #11 on: October 24, 2011, 05:10:11 PM »
- Good oxygen exchange (if possible. In the lab, it's filtered air or for liquid media, bubble oxygen through it),
- 85+ % humidity (not mandatory, it will grow in less),
- and 86F (this one is very important)

I have attached a PDF on an old time procedure before in another thread for growing on bread cubes, it has more details. if you are gluten intolerant, you can grow it on white rice. Adjuncted with citrate buffer, rice media will produce higher yield. Target is 72 hrs for peak spore collection. And for long-term storage, can store in hypotonic solution in the fridge, or glycerine saline (with buffer if you want) in the freezer.

edit: please ignore everything that doesn't make sense, it's just me babbling :)
« Last Edit: October 24, 2011, 05:17:32 PM by linuxboy »

gstone

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Re: How do you use Penicillium Roqueforti?
« Reply #12 on: October 24, 2011, 05:20:27 PM »
Not seeing the attachment, linuxboy.

I think non aoc branded brie or camembert doesn't have an active mold culture.
It's been a while so I don't recall the brands, but I've had neglected bries in the fridge where the mold begin to grow out over the cut parts of the cheese.  I think I'll do some experimenting.
« Last Edit: October 24, 2011, 05:26:04 PM by NW Fromager »

linuxboy

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Re: How do you use Penicillium Roqueforti?
« Reply #13 on: October 24, 2011, 06:36:41 PM »
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in another thread

http://cheeseforum.org/forum/index.php/topic,5165.msg57071.html#msg57071
 :)

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doesn't have an active mold culture.

No, all bloomies in that style (brie/cam) have an active candidum that should be harvestable unless it is really way old and dead.

Offline Aris

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Re: How do you use Penicillium Roqueforti?
« Reply #14 on: October 24, 2011, 11:39:05 PM »
Aris, I don't know if it helps, but I age the moulded bread to 45 days and I make/use a dryish bread with a high proportion of rye flour in it. It can be done the Roquefort way, by cutting a slit in the side of the flattish bread and inserting the blue mould, then leaving it for the 45 days in a designated area. That way, all the mould develops on the inside of he bread, which can then be crumbed. I suppose the thinking is that having the internal mould only stops a lot of the spores from floating about where they're not wanted.
I use bread flour and the blue mold have no problem growing on it. As of now its 30 days old and its really really moldy inside and outside because i used the mold from a Roquefort which seems to have a very aggressive strain of blue mold. While the piece from a Bleu D' Auvergne that i used before grew at a slower pace and has a less intense color and growth.  As long as there is mold present, it can be used. No need to age for that long imo.

NW Fromager,
Another way of inoculating the milk is diluting the powder in water and let it hydrate until the water is very bluish or greenish which would take an hour or so.  After that, pour the water onto the milk while using a fine cheese cloth to filter the bread particles.  This gives a much better distribution of spores in the milk.