Stretching the cheese forum to include a question or two about tofu.

[bernardsmith]

I have started to make my own tofu. If you haven't tried to make tofu it's a lot like making cheese but involves a great deal less time and you press the curds for perhaps 30 minutes to an hour. Anywhey, as they say, my two questions:
1. Is the secret to making a very firm tofu related to the amount of coagulant you add rather than the amount of pressure you place on the curds to remove the soy whey? And
2. I understand that one technique used in making tofu uses the cultures that grow in the whey to coagulate the soy milk. (Vietnamese tofu). Does anyone know a) the pH of the whey I should be looking for ? and b) the amount of this whey I need to add to say, one gallon of soy milk? Thanks.

 

[SoulToast]

1. Is the secret to making a very firm tofu related to the amount of coagulant you add rather than the amount of pressure you place on the curds to remove the soy whey?

I think a little more time in the pressing can help, along with a good cold ice bath for a good hour to help set.

I need to do some more disciplined experimenting with coagulant ratios soon, and wonder if running the curd through a blender before pressing would help get a more homogenized block. Mine always turns out...not gritty, exactly, but prone to falling apart if I wasn't careful in the cooking. No vigorous stir frying, but really good in hot and sour or miso soup.

Thanks for opening this little can of worms, though. I stumbled on a stash of soybeans in the pantry the other day, and was thinking about running a batch. I'll keep notes and report back!

 

[bernardsmith]

Curious. Wouldn't running the curds through a blender destroy them? You wouldn't treat fragile curds like that if these were milk curds. Does the fact that these are soy curds mean that their fragility is not an issue? I THOUGHT that perhaps stirring the curds while they formed might help but I see that there are some youtube videos that suggest that you treat those curds much like we treat cultured milk once we add rennet. You don't touch it until you are ready to cut the curds.

 

[SoulToast]

Good point. The evil part of my brain making the suggestion thinks of silken tofu... not having done any additional research, of course.

Worst case, I end up with something weird I have to repurpose. I haven't managed to get a proper mozzarella since I moved, and the two recent failures have become a sort of poor man's halloumi.

I picked up a soy milk maker a few years ago, so the effort involved is almost nonexistent.

 

[bernardsmith]

Sidebar: but there really is no effort in making soy milk. Don't even have to soak the beans. You simply add cold water, bring them to a boil and simmer for about 5 minutes, then pulverize in a blender with about 1 gallon of water to every pound of dry beans. I've found that taking the okara and putting it back through the blender a second time gives me a volume of curds from the soy milk that I am looking for from the pound of beans. But then I am from Scotland and the thought of buying a kitchen tool that has only one single function is not something I can bring myself to buy.

all that aside - I am looking for very firm tofu and I suspect - that the amount of coagulant is probably critical and my problem is that none of the recipes I have really discuss amounts in any way that you can easily make larger or smaller volumes knowing precisely how much coagulant to add and at what strength or pH etc..
for the type of tofu sought after.

 

[Staestc]

You may have already seen this, but the recipe on Cultures for Health has tips before the recipe that state:

• The amount of coagulant used will influence the texture of the final product: For instance, more coagulant will produce firmer tofu, while less coagulant will produce softer tofu.

• If you plan to consume the tofu within 24 hours of it being made, there is no need to store it in water.

• To give the tofu a more fibrous texture, cover the tofu in water in a sealable container and place in the freezer. Thaw when ready to use.

(https://www.culturesforhealth.com/learn/recipe/soy/homemade-tofu/)

The recipe lists three possible coagulants but does not discuss what, if any, differences there may be between them. Two are just different forms of Magnesium Chloride and the third is Calcium Sulphate.

 

[Staestc]

I found something else on thespruceeats.com that talks about the difference between the coagulants Nigari (magnesium chloride) and Gypsum (calcium sulfate).

"Nigari, which has a slightly bitter taste that many people happen to like, is often used to make this recipe. If this is not to your liking, gypsum results in a less bitter taste and creates the same firm, smooth tofu as nigari (and it adds a lot of calcium to your block, too). Some recipes recommend using Epsom salt, which sounds nice because it’s widely available, but it results in a grainy tofu that’s neither tender nor firm."

 

[bernardsmith]

Thanks Staestc. I had seen the Cultures for Health piece and that was what had prompted me to post my question after a few days of research into waht was publicly available but the piece itself does not make any suggestion as to what difference in quantity one should aim for to make firmer tofu (twice as much? four times as much? 1.5 times as much? and I have been using lemon juice rather than chemicals and I was planning on using the soy whey which after a few days has the ability to coagulate a fresh batch of soy milk without then adding alien flavors to the tofu , so how much soy whey is used /gallon of milk? One article I read was very coy about volumes advising the readers that those who know how much to add know how much to add and they learned by experience (and they are not telling).
With regular cheese making there is a whole library of literature on the amounts of coagulant (animal rennet, microbial rennet, vegetable rennet) at specific concentrations to be used on specific volumes of milk but in tofu making that literature seems not to be so readily available.

 

[Staestc]

I still have not found anything on how much coagulant does what in regards to tofu, but I did find some pretty cool info on coagulants.
On this page I found a cool article

http://www.ift.org/food-technology/...ssing-how-tofu-is-processed.aspx?page=viewall

I extracted the coagulant bit for grins just to see if I could post it here and have it be readable.

There are some good points on this site as well

https://www.vietworldkitchen.com/blog/2012/10/tofu-coagulant-guide.html

I'm interested in making tofu so I am going to check the place in town where I get my cream line low temp homogenized milk for cheese because I am pretty sure they will have soy beans too! May try my hand at making tofu this weekend

 

[Staestc]

Well, it's a little hard to read the extract, but the web site address is there so it was unnecessary anyway

 

[bernardsmith]

Stretching my tofu post even further but bringing this home given that this is essentially a brewing and fermenting forum. Just came across a wonderful little paper published in the Int J Food Microbiology (262, 2017 14-22) by Jian-Yong Chua et al. that discusses their experiment making wine from soy whey using commercial wine yeast. They were able without any problems to make soy wine at 8% ABV. But inter alia the authors state that they added Calcium Sulfate (gypsum, I think) to coagulate the soy milk at 2% (w/w) of the original dry beans. So if they were using 500 g of dried beans then they would have added 10 g of gypsum and if they were using 1000 g of beans then they would have added 20g of gypsum). So I now have a formula for the amount of gypsum to use... and I now have an idea of what to do with the leftover soy whey from making tofu - They made a wine which they said tasted very fruity and not at all bean-like... I am going to make a mead.