Guys and gals, I am using a domestic fridge that I have fitted a temperature control unit to and has it set at 12.5C. It varies by no more than 0.5c either way. But, I can not resolve the humidity issue.
I have placed a humidity meter in the fridge and it reeds around 47%RH so I placed a bowl of water on the bottom shelf and it raised by 1% the following morning. I have now filled the salad drawer with about a litre of water and it still sits at about 50%RH two days later. The only time it gets anywhere near the 80% I need is when I constantly open and close the door for a minute or two but of course, this is only temporary!
I just opened my first cheddar made a few months ago that has been vac packed to mature so that I needn't worry about humidity and it is slightly bitter with little flavour (This was my first cheese). Bland in fact! I've been informed that this is likely due to vac packing as it doesn't mature well when vac packed.
I don't want to make cheese just to throw the poor results in the bin so can anyone help me to increase the humidity and suggest how I might maintain 80%RH?
Also, if I were to resolve the humidity issue would leaving the cheddar a couple more months in decent humidity improve the flavour or is gone now?
EDiT: I am in UK
The simplest thing to try if you have a spare shelf at the bottom is to spread out a doubled over towel and keep it wet. The more wet exposed area you have the higher your humidity will be, so you can be creative as to how you arrange and drape the towel. Because of the dehumidification effect of the fridge compressor the more it runs the harder it is to keep %RH high. If you have a fridge or wine cooler that doesn't have an air circulation fan it will be more difficult. Raising your fridge temp a degree or two will help some. The more cheese you have will also help. You can also try using a humidifier wick like this one (https://www.amazon.com/Vornado-MD1-0002-Replacement-Humidifier-2-Pack/dp/B000E1385Y/ref=sr_1_4?dchild=1&keywords=vornado+wick&qid=1596805150&sr=8-4) standing up in a small narrow pan of water. These are all "static" remedies but if you search the forum you will find other more elaborate you can try.
Quote from: John@PC on August 07, 2020, 01:06:56 PM
The simplest thing to try if you have a spare shelf at the bottom is to spread out a doubled over towel and keep it wet. The more wet exposed area you have the higher your humidity will be, so you can be creative as to how you arrange and drape the towel. Because of the dehumidification effect of the fridge compressor the more it runs the harder it is to keep %RH high. If you have a fridge or wine cooler that doesn't have an air circulation fan it will be more difficult. Raising your fridge temp a degree or two will help some. The more cheese you have will also help. You can also try using a humidifier wick like this one (https://www.amazon.com/Vornado-MD1-0002-Replacement-Humidifier-2-Pack/dp/B000E1385Y/ref=sr_1_4?dchild=1&keywords=vornado+wick&qid=1596805150&sr=8-4) standing up in a small narrow pan of water. These are all "static" remedies but if you search the forum you will find other more elaborate you can try.
Thanks John, I'll give it a go. I have currently got about a litre of water in the salad drawer and it still wont go above 55%
I meant to add if those don't work mini-caves could be an option if you have the space.
Quote from: John@PC on August 07, 2020, 08:21:19 PM
I meant to add if those don't work mini-caves could be an option if you have the space.
Not sure what mini cave refers to. If it is building a small area to control these conditions then not possible as I am renting! :(
When I was using a smaller mini-fridge, spreading a wet towel didn't get the humidity high enough for me. One thing that did work, though, was getting a very small desk fan (4" diameter maybe) and draping a wet towel over it, so it was blowing the moisture into the air. My next step up from that was a $15 ultrasonic bubbler, which was really amazing. All things to try!
Sorry, I should have called it a "ripening box" to avoid confusion. A lot of home cheese makers age their cheese in separate plastic containers large enough to put the cheese in and still have a little bit of room for air. You then control the humidity around the cheese by how much of a gap you have in the lid. For pressed cheese at 85% RH you would have the lid slightly askew, and for higher-moisture cheeses like blues and bloomies you can pretty much have the lid nearly closed. If you're box is big enough you can put a small humidity sensor inside. Just make sure you have something in the bottom of the box like a plastic mesh or sushi mat to give some space the cheese and box and allow for any drainage. If you search the forum for "ripening box" you will see a lot of examples and tips. Some cheese makers use ripening boxes exclusively and don't worry about trying to keep the whole fridge humidified. It also has the advantage of isolating the cheeses and avoiding cross-contamination of beneficial surface molds.
Quote from: dmitrig01 on August 07, 2020, 09:31:50 PM
When I was using a smaller mini-fridge, spreading a wet towel didn't get the humidity high enough for me. One thing that did work, though, was getting a very small desk fan (4" diameter maybe) and draping a wet towel over it, so it was blowing the moisture into the air. My next step up from that was a $15 ultrasonic bubbler, which was really amazing. All things to try!
Definitely idea's to think about.
I have just got to bed (pm here in UK) and half filled the drawer at the bottom of the fridge and placed a damp towel with one end in the water and the other sitting on the bottom shelf. Maybe capillary action will bring enough moisture into the main compartment. I'll see what the RH% is in the morning.
I really appreciate all of your suggestions guys. Somewhere there will be a solution!
Quote from: John@PC on August 07, 2020, 09:54:30 PM
Sorry, I should have called it a "ripening box" to avoid confusion.
No worries John. I may have to look at that. ideally I'd like to get the wheels out of the vac packs but need to sort a reasonable humidity first! Thanks
Ripening boxes are the way to go. Normal refrigerators usually can't maintain high humidity by design. It helps to think about what RH is in order to understand why.
Air can hold a certain amount of water vapour. The amount it can hold is dependent on the temperature. The higher the temperature, the more water it can hold. If the air has more water than it can hold, then the water condenses out. Imagine that a certain amount of air can hold 100 ml of water at 20 C. But at 10C it can only hold 40 ml. That means that if your air is holding all the water it can at 20 C and you reduce the temperature to 10 C, then 60 ml of water will condense out (I'm just making up the numbers -- I don't know how much water air can hold at different temperatures.... probably you can google to find out if you are interested).
RH (Relative Humidity) is the percentage of water that the air is holding compared to the amount that it *can* hold. If we take our hypotherical air at 20 C, if it is holding 100 ml of water, then it is at 100% RH. If it is holding 80 ml of water then it is at 80% RH. If it is holding 40 ml of water, then it is at 40% RH. You get the idea.
Now imagine that we take an average day of 20 degree weather with 40% RH. We then cool that air to 10 C. It goes from 40% RH all the way up to 100% RH -- because 10 C air can only hold 40 ml of water. That's exactly the amount that we happen to have in the air. Again, I'm just making up these numbers.
What used to happen in older fridges is that they would literally be swimming in water. You would have to wipe them out all the time. The freezer, especially would just end up being full of ice. Because the freezer is at -10 C or something, it can hold almost no water. So the air is *always* at 100% humidity. Slowly over time, the water would come out of the air and grow ice crystals on the walls of the freezer and eventually the freezer would be full of ice crystals (at which point you would have to unplug the fridge and "de-ice" the freezer).
Having your fridge and freezer continually at 100% humidity is really bad for your food as well. So some smart engineers realised that they can build a dehumidifier in the fridge. This makes it so your fridge is not continually dripping and your freezer is no continually getting filled up with ice crystals. But for a cheese fridge, it's not particularly good.
The short story is that if you can find a particularly cheap bar fridge, it might not have a dehumidifier built into it. Or, you *might* be able to overwhelm the dehumidifier built into your fridge... but it's always going to be a losing fight, I think. The other problem is that fridges are designed such that they are cooled using plates (or coils) at the rear of the fridge. This makes the walls of the fridge cooler than the air (basically, the cold walls cool down the air in the fridge). Just like a window on a cold morning, this will gather condensation (the walls are cooler than the air, so the air next to the walls have a high RH, which means that water will condense on them). So this means that as you increase the RH in the fridge, the walls of the fridge will *always* be running with water and you have to find a way to soak it up, or drain it (very old fridges without dehumidifiers have drains in the bottom of the fridge for exactly this reason). It's going to get covered in mold and... just be a complete PITA.
The better way to make a cheese cave where you leave the cheeses open is to buy an air conditioner and a humidifier. You build an insulated box and you blow cold, humidified air into the box. This way the walls of the box are warmer than the air. So as long as you always stay below 100% humidity, you don't get condensation on the walls of your cheese cave.
But... like I said, maturation boxes are 100% the way to go if you just want to have a hobby making cheese.
Quote from: mikekchar on August 07, 2020, 11:27:19 PM
Ripening boxes are the way to go. Normal refrigerators usually can't maintain high humidity by design.
I would agree with that and the rest of your very informative post. That said back when we had our Perfect Cheese LLC business running we made and sold (I'm estimating) 200 or so "Cave Cube" evaporative humidifiers with very good feedback. Yes, it does depend on the refrigerator design and how much water vapor is being pumped in but even with "difficult" situations including refrigerated surfaces that are more prone to condensation and wine fridges we were able to hit 85% RH with few exceptions. Personally, if I was making mostly white mold, surface-ripened or blue cheese I would go with ripening boxes exclusively. But if the majority were pressed cheeses I would try a humidification system and put the bloomies and blues in separate boxes (which is what I'm doing now). Part of the reason is convenience: it's easier and faster to do you daily flips without moving around boxes. Also, ripening boxes can be a bit difficult to "fine tune" %RH and do take up valuable cave space. But if you like to wax or vac pack I could see where boxes would be a simpler way to go.
I might just have to stick to Vac Packing.
The only reason I started looking at humidity in my fridge was because my first cheddar is very bland in flavour and I was told the reason is vac packing. So, would aging longer cure this problem? Or maybe a little extra culture to start with?
A natural rind does influence flavour, but the vast majority of flavour comes from aging. Rather strangely, flavour is developed after the starter culture is dead. The bacteria cells contain enzymes. Once the bacteria dies, the cell walls break down, releasing the enzymes. The enzymes then break down the protein in the cheese. You can think of proteins as big long chains of chemicals. The smallest link in the chain is called an amino acid. There are many types of amino acids and each have a different flavour. If you link up amino acids, they form peptides. There are many types of peptides and each have a different flavour. If you link up peptides you get proteins. Oddly, the proteins don't have much flavour. An enzyme is a chemical that breaks apart other chemicals. In this case it breaks apart proteins into peptides and peptides into amino acids. There are many types of enzymes and each enzyme breaks apart different kinds of links. So depending on the enzymes, the proteins will break down into different peptides and amino acids. Also, each enzyme is active in a different temperature range.
So the long and the short of it is that depending on the bacteria you have in the cheese, you will get different enzymes. Depending on the temperature that you age the cheese at, you will activate the enzymes at different rates. All of this will generate different flavours. But the most important thing is time. A good sharp cheddar takes about a year to develop flavour. At the beginning, there isn't much flavour -- just a little bit of yogurt flavour, or butter flavour from the fermentation of the starter culture. After 2-3 weeks, the starter culture has basically died off and you start to get some flavours developing. Over time, the flavours change because you are slowly chopping up the proteins in different places and producing different flavours. After a month or two you'll get a mild cheddar flavour.
Growing mold on the outside of the cheese allows new enzymes to enter the mix. It doesn't really increase the flavour -- just changes it. Different enzymes break the proteins at different places which produce different percentages of peptides and amino acids, which changes which flavours are produced. But the strength of flavour is just a factor of time, really.
Thanks for this mikekchar. Always good to understand the science behind the process. One thing lacking in many books unfortunately!
Mine has been aging for about 3 months in fridge at 12C that was vac packed after the first few days of air drying. It has a slightly tangy taste but very bland in terms of flavour. (Also a little crumbly which may be slightly dry) I'll leave it another couple of months and taste again!