Author Topic: DVI v. Primer Culture - a benefit in a lag in ΔpH/renneting pH target?  (Read 4119 times)

Offline ArnaudForestier

  • Old Cheese
  • *****
  • Location: Madison, Wisconsin
  • Posts: 1,546
  • Cheeses: 45
  • Default personal text
    • Paul's FB
Not sure where to put this.

Just a thought, going back over old notes.  From Pav's help, looking for a ΔpH before renneting of maybe (0.02) or so, and a pH somewhere fairly close to 6.5.  This is specifically with tomme in mind, but it's a more general question for me, comparing DVI to primer culture (or bulk-set culture) generally. 

I note that when I use a primer culture, as opposed to a DVI culture, I achieve that change (and often, that pH) virtually instantaneously, as opposed to the lag time I experience with DVI.  My memory, in terms of preserving calcium in Beaufort makes, was that "low and slow" is better, in this way - a longer acid curve tended to give me better makes, not the least reason of which was probably (my memory's hazy, so forgive any errors) was that the slower acid curve allowed more calcium phosphate to be entrapped in casein micelles, less lost in whey, and you end up with calcium in place when you want it, for these types of cheeses. 

The one thing that always bedeviled me about using primer culture was this one issue, this immediate drop to the suggested pH range for renneting, as opposed to the long, slow drop I experienced with DVI. 

Granting I may have this all screwed up, I'm just curious (once again):  Experts - Pav, others - what's your feeling here?  Is this instantaneous ΔpH when using primer culture a potential problem, if trying to preserve calcium, and if so, is one perhaps better off actually going with DVI, specifically for its lag?
- Paul

linuxboy

  • Guest
Re: DVI v. Primer Culture - a benefit in a lag in ΔpH/renneting pH target?
« Reply #1 on: January 21, 2014, 03:23:20 AM »
No, stick with bulk unless you don't want to go through making bulk. Add culture, stir, wait for 5-10 mins while you prep some other things, and add rennet. You're talking about rather miniscule changes here. Drain before 6.4 and you'll be fine with the tomme.

Offline ArnaudForestier

  • Old Cheese
  • *****
  • Location: Madison, Wisconsin
  • Posts: 1,546
  • Cheeses: 45
  • Default personal text
    • Paul's FB
Re: DVI v. Primer Culture - a benefit in a lag in ΔpH/renneting pH target?
« Reply #2 on: January 21, 2014, 03:37:24 AM »
OK, thanks, Pav, will do.  As you know, in case it helps others, seeking a moldy tomme, something I've never done before as I've always done a lot of washed rind, bacterio-centric cheeses.  Also seeking a softer pate than all my previous tommes.  After thinking more on this, though I'm trying for tomme grasse fermieres des bauges as a model, it occurs to me I might look to sharing some characteristics I've experienced in St. Nectaires...  I'm going to go for slightly larger cut (1/2") and a 3.5 multiplier, and do what I can to preserve moisture.   

Edit: "baux des fermieres" he said.  What a rube.  ;D
« Last Edit: January 21, 2014, 03:52:04 AM by ArnaudForestier »
- Paul

Offline ArnaudForestier

  • Old Cheese
  • *****
  • Location: Madison, Wisconsin
  • Posts: 1,546
  • Cheeses: 45
  • Default personal text
    • Paul's FB
Re: DVI v. Primer Culture - a benefit in a lag in ΔpH/renneting pH target?
« Reply #3 on: February 27, 2014, 08:40:48 PM »
No, stick with bulk unless you don't want to go through making bulk. Add culture, stir, wait for 5-10 mins while you prep some other things, and add rennet. You're talking about rather miniscule changes here. Drain before 6.4 and you'll be fine with the tomme.

I'd like to pick this up again, a bit.  I recall a conversation somewhere, Francois and Pav, about a "lazy Frenchman," and I think it was to the subject of this thread.  I know when I add MC at the rate of, say, 1%, I get an immediate ΔpH of 0.1 or higher.  Somewhere else, I recall an optimal of 0.1-0.15, with 0.1 probably better, for alpine styles. 

That would mean, I rennet immediately. Pav, haven't seen you much lately but if you're around, what specifically is the reasoning that is the crux of the "lazy Frenchman" debate here?  My brewing days are sitting on my shoulders - one wants a lag, because the lag means yeast aerobic respiration, budding, and all the related byproducts of respiration.  That's why we don't pitch in the terminal population density, we want growth, in the fermentor, so we deliberately under-inoculate, to use the term broadly.  Isn't it the same here? 

To take extreme examples, if DVI can take upwards of 1 hour or (sometimes, much) more before getting the proper renneting ΔpH, and MC can result in an immediate renneting ΔpH, isn't there a benefit of coming in at a lower MC dosing, say, .5%, resulting in maybe a 1/2 hour lag?

I guess I have to think renneting immediately, and renneting with a lag of some kind, has to make a difference in the quality of the cheese one ends up with.  I'd just appreciate learning more as to why.

Even if the difference are miniscule, what are the differences, here?  Pav?  Francois? 
- Paul

Sailor Con Queso

  • Guest
Re: DVI v. Primer Culture - a benefit in a lag in ΔpH/renneting pH target?
« Reply #4 on: February 27, 2014, 08:53:43 PM »
That's sort of what I do. I found that with a 2% bulk inoculation some of our cheeses were developing too much acid by the time they were pressed. So we now inoculate at 1% and then wait 15-20 minutes before rennet. By doing that, we start with 1/2 the bacteria, but theoretically within 30 minutes or so we end up with the same bacteria count that we would have had with an initial 2%. It seems to make a big difference in our makes.

Offline ArnaudForestier

  • Old Cheese
  • *****
  • Location: Madison, Wisconsin
  • Posts: 1,546
  • Cheeses: 45
  • Default personal text
    • Paul's FB
Re: DVI v. Primer Culture - a benefit in a lag in ΔpH/renneting pH target?
« Reply #5 on: February 27, 2014, 09:01:15 PM »
Sorry, I'd forgotten that I asked already, and this was discussed.  I blame the meds. :-[
- Paul

linuxboy

  • Guest
Re: DVI v. Primer Culture - a benefit in a lag in ΔpH/renneting pH target?
« Reply #6 on: February 27, 2014, 09:05:30 PM »
Quote
theoretically within 30 minutes or so we end up with the same bacteria count that we would have had with an initial 2%.
Paul, I will reply to all your emails this weekend. Traveling. 

Wanted to share something I've learned. LAB have rather different growth rates during exponential phase. I have seen some LAB at optimal conditions take 90+ minutes to split. I've rarely seen lactococci pull off fission in 30 mins. That means knowing the growth profile and pitch rate for specific species and strains is pretty important. Much harder calcs than beer or other saccharomyces ferments. It's often down to guess, adjust, and finalize for fine tuning recipes.

Offline ArnaudForestier

  • Old Cheese
  • *****
  • Location: Madison, Wisconsin
  • Posts: 1,546
  • Cheeses: 45
  • Default personal text
    • Paul's FB
Re: DVI v. Primer Culture - a benefit in a lag in ΔpH/renneting pH target?
« Reply #7 on: February 27, 2014, 09:07:24 PM »
So Sailor, coming in at 1% you experience a lag, then.  I'm getting no lag, and I'm wondering why.  I probably could be more careful in terms of how much MC I'm pitching - i.e., a BIG difference between a rounded 4 ounces and a tight 4 ounces.  The other thing I'm wondering is if the terminal pH of the MC is lower than expected.  (I know what it is at the end of ripening and going to the cooler, but have gotten lazy and haven't been measuring it the day of the make). 

If it's lower, in that case, I also reasoned the MC would experience acid injury, so that would slow its start (bad practice, I know). I think I'll stop the MC ripening sooner, mark not only the pH going into the cooler, but the MC pH the day of the make, and see if I can't figure it out. 

In general my acid curves have been way too fast, and the only thing I can figure out is either there's too much initial counts in the vat, or my temps are higher than I think they are. 

Thanks, Sailor, comforting to know this is what you do.  I used to use 1% and it was great, too, for me, so I know something's different now.  Back to the drawing board. 

Cheese for the help!

Paul

Edit:  No worries Pav, thank you.  And I could intuit that this is a seriously more complicated system than a simple yeast-based environment, but woefully ill-versed to know the exact dynamics involved.  Will think on this and watch your and Sailor's thoughts with great interest, thanks, gents.  Cheese to both of you!
« Last Edit: February 27, 2014, 09:16:53 PM by ArnaudForestier »
- Paul