Author Topic: Rennet Revelations  (Read 2893 times)

Alpkäserei

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Rennet Revelations
« on: May 05, 2014, 08:54:54 PM »
I have come to the understanding that I completely misunderstand rennet as it is presented and used in the US.

This will have a bearing on everything I have ever said about coagulation.

Here's the deal,

Swiss cheesemakers use the same strength rennet as is typically used in the US. Specifically, 1:15,000 for liquid rennet.
However, while they do label it with this strength, they don't use it like that.

I realize I learned a totally different set of rules, where that exact same rennet (standard 1:15,000) is stated as being suitable for the strength of 1:9000 (± 5%)

We specifically used 1:15,000 liquid rennet in the proportion of 1 ml rennet for every dl milk, or 10ml per 100 l. That is a super convenient proportion, and worked very well. Then our cheese would coagulate for 30 minutes. Yes, that's actually 1:10,000, a little outside of the 1:9000(± 5 %) range, but it works great.


This means that our coagulation times are going to be a lot shorter than what you would have using the 'standard' method.

So from now on, I need to be careful to point that out. If I figure right, our coagulation time would be 60 to 70% of what you have using standard proportions.

That means if you are using rennet in the proportion of 1:15,000, a cheese we would set for 30 minutes should be set for 45 minutes

Suddenly, all my confusion regarding American cheese making and the vast discrepancies between the alpine tradition is cleared up...

linuxboy

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Re: Rennet Revelations
« Reply #1 on: May 05, 2014, 09:34:12 PM »
And what's your time to soft set (initial gel) about 15-18 minutes? Because milk pH is ~6.6, right?

Alpkäserei

  • Guest
Re: Rennet Revelations
« Reply #2 on: May 05, 2014, 09:57:48 PM »
depends on the season, but pretty much yes right in that area.

Traditional alpine makes don't put any ripening time before renneting, so basically you have whatever the milk's initial pH is

But, alpine cow breeds tend to produce a slightly more acid milk too, one of the reasons I aim for them.

Alpkäserei

  • Guest
Re: Rennet Revelations
« Reply #3 on: May 06, 2014, 08:07:15 PM »
What exactly is the effect of adjusting the rennet amounts?

Yes I understand it acts faster (first, is this a direct relationship as in, doubling rennet will halve the coagulation time, or is it fractional, like doubling rennet will cut 1/4 off the time?)

But, all time factor adjustments taken into consideration, what effect does more rennet have on the final cheese? What effect, specifically, does it have on aging and flavor? Does it have an effect on how the curd releases its moisture during the cooking stage?

Also,

When exactly does the time factor in renneting stop? What change causes the curd to stop binding moisture into itself?
For example, if I adjust the brewing time where the already cut curd is gently stirred and matured before the temperature is increased, I assume this is going to have a direct effect on the moisture content -I assume this based on direct observation, where a longer brewed curd is a bit softer and more pliable.
I would just tend to assume that the complete time factor of the make matters when rennet is concerned -which would imply that if your time to curd cutting is off target, you should probably adjust other stages accordingly. (like, if the curd took too long to set, you should cut it more slowly and brew it a little longer so the rennet-time factor works out through the entirety of the make. This with alpine style cheeses where the culture-time factor in the vat is fairly insignificant)

My thought would be that cutting the curd doesn't STOP the chemical process (because that wouldn't make any sense) but it does slow it down by causing most unbound moisture in the gel to break loose of the curd, thus making it less 'available' to be chemically bound. This of course relates directly to cutting speed and curd size. Then of course curd size also plays a factor into how moisture is forced out of the curd when it is heated.

This is all my theory based on observation and experience, and just conjecturing about what makes sense to me. SO I could be way off here.
But I am trying to put together a collection of accurate information and would like to explain WHY things matter how they do.
Specifically, I am trying to understand the aspects of rennet time, cutting time, cutting size, and the overall time factor of the make.

linuxboy

  • Guest
Re: Rennet Revelations
« Reply #4 on: May 06, 2014, 09:12:30 PM »
From "Gel firming rate of rennet curd as a function of rennet concentration"


Alpkäserei

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Re: Rennet Revelations
« Reply #5 on: May 06, 2014, 09:39:29 PM »
can you define the variables?