Making fish sauce -- Results

I'd like to show the results of my fish sauce experiments. I catch herring each year and in the past few seasons have been using the heads, guts, gills and blood to make fish sauce. It's actually quite easy--fish parts plus 20 percent salt by weight--and the process turns out fish sauce in 6 months to a year. It's also a nice way to reduce waste. I am now filtering the sauce out of last year's fermented herring, as well as fish sauce made from last summer's salmon guts and gills. (I think any oily fish would do.) Attached is a photo. The tall bottle contains herring sauce, and the smaller three bottles contain salmon sauce. A gallon of fish parts and salt seems to yield nearly half a gallon of sauce. It adds a blast of umami flavor to whatever you're cooking, and it works nicely as a drizzling sauce. If you want any tips or advice, let me know. It's well worth the effort.

That’s pretty awesome.  I’d love to sample both

Nice! What sort of vessel are you fermenting in and at what temp?

Cheers,
Brad

I've been using one-gallon glass mason jars as well as food grade plastic buckets (specifically a beer brewing bucket). I just ferment at room temperature, although warmer is better. Some sources say to ferment fish sauce at 80, 90 or 100 degrees. With herring, since we catch them in winter, it's hard to do that.

To filter the fish sauce, I layer four or five clean (no soap!) cotton hand towels in a large colander placed in an even larger salad bowl and then dump the mash in. The liquid that pours through in the first ten minutes will be pretty cloudy, so you'll want to recycle it back into the colander. To do that, momentarily place the colander over a second bowl, pour the cloudy fish sauce into a glass, then put the colander back (or leave it on the new bowl). Pour the cloudy fish sauce back into the colander. At that point, it filters through slowly and very clear, in my experience. Every hour or so you'll want to pour the filtered fish sauce into a wine bottle or whatever you'll store it in. This filtering can go on for a few days. 

Also, the 20 percent salt by weight measurement is pretty important. As near I recall, research shows that botulism can develop in environments with less than about 10 percent salinity. So, 20 percent offers a large margin of safety. You could go higher, too, but I would not suggest going lower, although I've heard of people doing fish sauce at 11 or 12 percent, I think. 

I hope that helps.

DayTripper, yeah!

Oh this is going to happen -- now I just need to hit one of the spawns!

Thanks for the inspiration and the 411

Cheers,
Brad

Does the sauce need to be refrigerated after bottled?  The fish sauce looks so good.
Thanks for sharing the recipes. 

Al

I keep mine in the fridge just because I have room, but I don't think it's necessary. Consider that prior to filtering and bottling the stuff has been at room temperature, and up to 100 degrees, for 6 months or a year. I think it's very stable, thanks to the salt.

Remember, you don't need to add water. The salt and enzymes turn the fish to gravy. Only the bones survive, which precipitate neatly to the bottom of the fermenting jar. I found a bird's nest of gillrakers at the bottom of my salmon jar yesterday. (I had used the gills and guts of my salmon.)

Thanks for the reply.  I think I am going to give it a try too.  By the way, does the container, that holds the fish guts and salt, need to be completely sealed (to prevent smells) or loosely closed (to allow ventilation) during the fermentation process?

wow this is too cool of a resource, I figured there had to be wizardry at work, but I think I might be able to handle a ferment like this. Thanks!

Thanks for the reply.  I think I am going to give it a try too.  By the way, does the container, that holds the fish guts and salt, need to be completely sealed (to prevent smells) or loosely closed (to allow ventilation) during the fermentation process?

Normally you want to have an airlock or some sort of way to burp the jar otherwise it will explode or carbonate as it off-gasses.

I love this and want to try it next chance I get, wife is going to hate it though, just like my kombucha 
Does it put off much stink?

I've been making fish sauce lately, too. It doesn't smell at all. Even if you open the jar, it barely smells. You really have to get your nose in there nd even then it barely smells fishy. Not a big deal!

As for allowing gas to escape, when using plastic fermenters without an airlock (just a screw on lid) I have noticed the plastic bulging out. When I unscrew the lid, there is a little burp of gas, but nothing like fermenting beer or kimchi. So, I don't think it's a big concern. Just use a screw-on lid and don't seal it too tightly.

As for the smell, it's not really smelly. It smells fishy when you get up close, but it is NOT rotting. You're preserving it, so the smells are not strong or foul.

I have had mold grow on the surface of some fermenting fish. It did not ruin it, though. Try and stir it shake it up routinely to prevent the mold.

The following paper, by the way, states that 10 percent salt by weight prevents Clostridium botulinum from growing. So remember to weigh your ingredients. Also, make sure the salt gets mixed through the fish pulp. If there is a clump of fish guts that is not mixed with the salt, it can start rotting--and that WILL stink! https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5076734/

Oh, another point: Do not clean out the stomach contents--tempting if you're using salmon guts, since they can look nasty. But you actually want the stomach contents, because you need the digestive enzymes from the intestines. This is not a Lactobacillus fermentation. It's the stomach enzymes that do the work.

The next frontier in the full use of the fish is to take the leftover mash, after draining off the fish sauce, and grinding it into paste for use in cooking. This is a thing in parts of southeast Asia, and the Romans supposedly did it, too, with their garum. I've tried it and it's very bitter. Maybe this is an acquired taste. Has anybody had bagoong? I believe this is a fermented fish paste.