Hi everybody. This is my first post here. I've been lurking for awhile.
I've been having consistent problems with bitterness in my hard cheeses. I never have problems with fresh cheese (eg chevre, mozarella) or bloomies or fetas, only pressed cheeses (gouda, jack, cheddar, etc).
These bad cheeses are also sharp (acidic) and sometimes have a pasty texture sometimes not. I usually crack them open after about 4-6 weeks because I want to get this problem figured out before I start long aging cheeses. Ones I have aged longer, say 6 months, continue to be bitter.
I use my own raw goat's milk. It's freshly drawn, and I practice strict hygiene. I haven't tried pasteurizing.
My first thought was maybe the Ph was off (it's frustrating that so many cheesemaking books don't even mention Ph). So I went out and bought a Ph meter, and made a half dozen wheels making sure I hit relevant Ph targets. For example, I salted my cheddar at 5.2 and drained my gouda at 6.1.
I also use about half the amount of starter a recipe recommends since I'm using raw milk (this is per the advice given by Caldwell in Mastering Artisan Cheesemaking and Kindstedt in American Farmstead Cheese).
I use calf rennet and use about a third less than a recipe calls for. For example, I used about 2.5 ml for a cheddar recipe using 3.5 gallons milk. This is per instructions is 200 Easy Cheese Recipes that say goat milk requires less rennet. I don't know the rationale for this.
I still find that I get a clean break faster than the recipes indicate, sometimes in half the time. So I cut the curds as soon as a clean break is achieved. Because of this early coagulation I may reduce starter and/or rennet amounts even more in the future, but it will be pretty hard to use less than I am doing now. For example, I used 1/16th tsp of MA4000 for my 4lb wheel of cheddar (I don't have a scale that will weigh quantities this small, so I've been using tiny measuring spoons - tad, dash, etc.).
Nothing else seems unusual during the make.
Today I cracked open and tasted five wheels that I'd made since I got the Ph meter. A pepper jack, a gouda, a cheddar, a tomme, and a lancashire.
Alas four of them had the bitterness defect. The lancashire was the only one that tasted good.
Since I hit the appropriate Ph targets, I am guessing that it is not a Ph issue. I'm also guessing it's not rennet related because I measure carefully with a pipette. The only other thing I can think of is salt content.
I looked over my notes and saw that the jack, gouda, and tomme (all were 3-4 lbs) were all brined in 18% brine for about 12 hours (flipped after 6). I make fresh brine every time. But one mistake may be that I don't use enough brine. I'm not sure of the total volume, but it's less than the 1:5 ratio I now see is recommended. More like 1:2.
The other thing that I noticed was that I over salted the lancashire relative to the recipe instructions. I used 72 grams (morton canning and pickling salt), when 2% by curd weight would be about half that. But when I tasted the lancashire it did not taste too salty. The salt level tasted fine, and it lacked the dreaded bitterness. I also noticed that I made the exact opposite mistake in salting the very bitter cheddar. I accidentally used half the amount of salt called for in the recipe. Oy! Can you tell I'm no good at math?
For comparison I went back and tasted the bitter cheeses. I could taste salt, but definitely not as much as in the lancashire. My conclusion is that I've been inadvertently undersalting. This strikes me as bizarre since I've been following recipe salting instructions (other than my two goof ups and having a perhaps too small volume of brine).
There may also be some naturally occurring lactic bacteria in my raw milk that, in the absence of sufficient salt levels, are producing bitter peptides(?). If so, this may explain why the cheese reaches the clean break stage too early, is overly acid even when 4-6 weeks old.
This most recent milk is also late-lactation. Though I've had the bitterness problem with summer milk also. Kindstedt says that late lactation milk, because it's higher in fat, takes up less salt and needs to be salted at a higher rate. He doesn't however give any indication of how much extra salt may be required.
So my question is, does any of this seem plausible? Could something else be causing this? If it is a salt problem, I can see how to fix it for cheeses where the curds are dry salted (ie just add more), but I'm not sure about brining. Should I just up the volume of the brine to get the recommended 5:1 ratio? Should I increase the brine strength and use a fully saturated brine? Should I continue using 18% brine and increase the time in the brine. If so, by how much? Is there anything else I should try?
Kindstedt has instructions for testing salt content, which require special test strips. If I can find them, I will test these wheels and that should give me a definite answer as to what the final salt content is.
I'll also continue to age these cheeses to see if the bitterness reduces over time, but given my past experience I doubt it will.
I've read in other posts that certain cultures can be added to reduce bitter peptides (eg Choozit FLAV series), but I can't find a source for these locally or online.
Sorry for the long post, but it's really frustrating having to throw out 75%+ of the cheese I make. Thanks for your help