Author Topic: Buttermilk & Yogurt Starter Cultures - Amounts  (Read 9952 times)

Gina

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Buttermilk & Yogurt Starter Cultures - Amounts
« on: April 29, 2010, 11:23:12 PM »
When a recipe calls for 1/4 teaspoon of a culture to be added, what is the equivalent in a frozen starter culture in terms of ounces?  For example, the manchego recipe from this site suggests 1/4 tsp culture of each themophilic and mesophilic - what does this translate to in terms of frozen culture cubes?

And when the recipe for parmesan says add 3 oz of thermophilic culture for one gallon milk, does one add a total of 9 ounces for 3 gallons? Is yoghurt a 1:1 replacement for a T culture, so that would mean adding 9 ounces?

Thanks for any clarification.
« Last Edit: May 01, 2010, 01:53:10 PM by Gina »

Gina

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Re: Buttermilk & Yogurt Starter Cultures - Amounts
« Reply #1 on: April 30, 2010, 07:27:16 PM »
Let me ask my question in a different way....  Those of you who use home-cultured buttermilk or yogurt or the like - when a recipe asks for 1/4 tsp of dry culture, how much of your homemade culture do you use?

Thanks

tally

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Re: Buttermilk & Yogurt Starter Cultures - Amounts
« Reply #2 on: April 30, 2010, 10:07:58 PM »
Thanks for asking these questions. I'm also confused about this issue. In a similar vein, when modifying a recipe (doubling, halving, etc) is there some proportional rule of thumb for the amount of milk and amount of culture/rennet? Or is each recipe individual  and should not be modified?

judec

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Re: Buttermilk & Yogurt Starter Cultures - Amounts
« Reply #3 on: April 30, 2010, 11:21:26 PM »
Yeah, good question.  I would also like to know this so I can start making my own cultures and know what to add.

Gina

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Re: Buttermilk & Yogurt Starter Cultures - Amounts
« Reply #4 on: May 01, 2010, 01:53:47 PM »
bump...

linuxboy

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Re: Buttermilk & Yogurt Starter Cultures - Amounts
« Reply #5 on: May 01, 2010, 02:58:57 PM »
OK, let me see if I can clear this up. The #1 consideration around which pivots all these decisions is the number of live, acid producing bacteria. In your cheesemaking, this should be consistent in terms of the bacteria count per pound of milk, so you can achieve consistent results.

The way this is measured, and I don't think manufacturers talk about it because it's sort of a geeky thing, is the number of colony forming units (CFUs) per gram of whatever culture you're adding, fresh in skim milk, cultured in 11% skim starter base, bulk frozen, or DVI/DVS. A CFU is just one active, viable, living, and non-damaged bacterium.

I've posted these levels before in various posts if you want to go back and read about more of how they're used and what they mean. And I'll post them again for your ease.

A DVI culture has anywhere between 1x10^ 11 (100 billion) to 1x10^12 or 10^13 (trillion, or more) CFUs/gram. A regular culture like yogurt or buttermilk, when very fresh has about 2x10^9 (2 billion) CFUs/gram. More if the the milk has a high protein content.

So what does this all mean? Simply that there is not a 1:1 relationship between a fresh prepared culture and a DVI. A yogurt culture may be old, frozen, or have high proteins, so the live bacteria may range anywhere from 500 million to 4-5 billion. Bacteria multiply every 20 minutes, so if you were in your recipe to use a yogurt with low bacteria count, it would take a few hours to get it to the right level as if you had used a fresh starter (like yogurt). Same for DVI. DVI culture will range from 100+ billion, to sometimes a trillion or more. That's why you need to weigh out the entire packet of DVI culture and resize. End point, there's no good way to have some sort of repeatable conversion between fresh culture and DVI UNLESS you use the same processes every time. For example, you always use only fresh culture and fresh DVI. Then you can get reliable comparisons.

Now let me answer your other questions. Sorry this is long, but it's vital to cheesemaking.

1/4 tsp of culture is about .75 grams. At 150 billion CFUs for the DVI, it will take about 75 grams of fresh starter to equal the same amount of bacteria. That's about .333 cups. If you are using frozen cubes, that depends on so many factors. For example, concentration of original culture, method used to freeze, temperature used to freeze, method of storage, length of time in freezer, etc. But figure about double the amount of fresh culture, maybe a little less or more.

Yes, for fresh starter, you increase is proportionally per gallon. Not exactly the same with DVI. You don't use 1 tsp per 4 gallons of milk, for example, because it's so concentrated. More like 1/2 tsp per 4-6 gallons.

Yogurt has thermophilic bacteria, so yes it is one example of thermophilic starter.

tally, some aspects are proportional... milk behaves differently in bulk. It's actually easier to use more than less. In general, use these as your starting point for most cheeses: 9-10 ml single strength rennet per 100 lbs of milk, or 4-5 ml double strength. and 1-2 DCU/Units per 100 lbs of milk. Resize from there to get the right amounts. I will add that the amount of culture changes with cheese types. Some use more, like cheddar, and some use less, like tomme. But those cultures for those cheeses also have different acidification curves.

Hope this helps.
« Last Edit: December 13, 2010, 03:34:12 AM by linuxboy »

Gina

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Re: Buttermilk & Yogurt Starter Cultures - Amounts
« Reply #6 on: May 01, 2010, 11:40:28 PM »
Quote
1/4 tsp of culture is about .75 grams. At 150 billion CFUs for the DVI, it will take about 75 grams of fresh starter to equal the same amount of bacteria. That's about .333 cups.

Quote
Hope this helps.

Yes, thanks for the information. I've read many of your past posts the past few weeks, as well as many from the other helpful people here. This place contains a wealth of information, though sometimes the right tid-bit can be hard to find.  :)

Although the concentration of a homemade bacterial culture obviously will be extremely variable (and make the more expensive pre-measured packets seem preferable), when one is just beginning to follow some of the recipes presented, one does need a place to begin with equivalent amounts, imperfect as it may seem. I also understand if I am lucky enough to make something good,  it will be more difficult to replicate.  :P



Offline DeejayDebi

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Re: Buttermilk & Yogurt Starter Cultures - Amounts
« Reply #7 on: May 03, 2010, 02:42:57 AM »
Generally speaking ... 1 cube of homemade buttermilk or yougurt culture per gallon of milk always worked well for me for most recipes.

Alex

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Re: Buttermilk & Yogurt Starter Cultures - Amounts
« Reply #8 on: May 03, 2010, 04:48:41 PM »
I use 1 ts of buttermilk/yogurt for 1 liter/quart of milk.

Nonius

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Re: Buttermilk & Yogurt Starter Cultures - Amounts
« Reply #9 on: May 06, 2010, 08:15:12 AM »
Hi Alex

You mean 5 ml on 1000 ml?
Do you use the regular Rivyon, or something else?
Do you use it straight from the supermarket, or do you let it 'culture' (how long/ temp?)

I just started a few months ago and used Giacomo's recipes as they are tuned to the milk and yoghurts here. His recipes call for 100 gr Leben/Gil on 5L, i.e. 20 ml/L of milk: twice or more what you are using. what is the secret: is leben so different from buttermilk?
« Last Edit: May 06, 2010, 11:10:37 AM by Nonius »