The thing about Trout...

[Jason Palenske]

With all the talk about Trout and their taste I thought it might be time for someone to chime in that comes from where they do.

First off, trout are not a dirty fish really, that odd dirty taste actually comes as a product of their environment. They can commonly be confused as tasting dirty just like catfish often are if they are cooked right after catching.

You have to remember that you are tank raising something that naturally comes from exceptionally cool extremely fresh water streams. Their natural environment is such that if you were to wade into a GOOD trout stream the water will be crystal clear and crisply flowing. This water flow keeps muscle or meat tone up with also constantly cleansing their body with clean dip your hand in and drink water. In a tank this is hard to accomplish without expense. Catfish are opposite of this in that they come from muddy slow moving water that can dirty their muscle or meat. Keep these things in mind when you judge their natural meat flavor.

Now a word on cooking Trout...

They are good to your grill and smoke. Butterfly the fillets out and leave the skin on, add butter and some lemon with a little salt maybe pepper. Grill until a purely white with some sear on the skin. You can also skewer them and rotate over a smoky flame with some cherry or apple wood. Another option to wrap in tin foil and toss in the fire mixed with veggies.

I hope this helps, remember before cooking trying running them through fresh water flow for a bit to let them clean their bodies first and you'll taste a world of difference.

[Jonathan Dyer]

As with many fish species world wide they have the tendency to take on the flavor of the environment they are living in, in many scenarios fish will store this ‘muddy’ taste in there fatty tissue this is normal and I wouldn’t say that this is a dirty trait, fish need to be purged accordingly. The thing about Trout grown in an Aquaponic system or re-circulation aquaculture for that matter is that the fish are swimming in its purging tank as the waste products are removed as well as sediment and fish effluent; a healthy Trout is a good indication of a healthy waterway, growing in a tank is no exception if things are not up to par this is due to poor management not the fish species so what I am saying is if the tank is not crystal clear and kept in pristine condition this needs to be addressed.

On doing so you are tasting the flavor of the fish for itself so cannot be seen as dirty nor should it be necessary to try and mask the flavor with every condiment under the sun in order to make it palatable (although it is still necessary). There is a massive difference between trout raised in freshwater opposed to seawater so is something worth thinking about as well.

[Hamish]

How do people purge their fish? I get the whole idea of putting them in clean water for a couple of week - but this must waste huge amounts of water as I assume you would need to do water changes each day to keep ammonia down as there would be no bacteria in the perge water to break down the waste. One thought I had was putting a couple of fish in a 200L plastic drum and hooking up my canister filter to it (canister that is already fully stocked with bacteria from a running system) And also doing 25% water changes each day. What do others suggest?

[Jonathan Dyer]

Your tank growing your fish is your purging tank, it is kept clean, wastes are removed, no muddy taste could occur. This is no different to what the commercial guys do, if wild stock are caught and purging is necessary a re-circulation tank is set up connected to bio-filters and the works the fish swim in the tank for a week with a small food ration sometimes no food at all and then off fro processing. Yabbies can be done in the same way but they are more commonly stacked in trays with water constantly sprayed on them dripping down to the lower tray and then to a sump, water is recycled and kept at cold temperatures to keep them docile, zeolite is sometimes used to remove ammonia.

Don’t think too much of it Hamish…Besides you are a veggo or are those Jades of yours egging you on to have a bite?

[Hamish]

I have to admit - they are a bit. If I am to be self sufficient I might need to look at these guys as a source of protein.... Long time to go before that becomes a decision for me though! Either way I would like to be able to serve them to friends and family in the tastiest possible way... For now they are just manure producing machines...

[Jason Palenske]

You know, if I had my choice when it comes to trout I would still want a separate tank running recycled spring water with a filter to purge them with if possible. Maybe it is just a mental stigma, but at least as far as a good trout stream in the states goes, you can drink the same water flowing next to the fish. I just don't see myself drinking off the hose hooked to the AP system full of trout though.

[Hamish]

That would be awesome - a bit like this episode of River Cottage

http://www.factualtv.com/River-Cottage-Forever-Episode-2

[Jason Palenske]

Pretty close, imagine you can see the bottom of that stream and you would be almost perfect.

[GaryD]

Hi,

While some people don't mind the taste of unpurged freshwater fish, it is the recommendation of the freshwater fish industry that all fish should be purged before processing.....in the interests of presenting the product to the market in the best possible condition.

Purging is accomplished by placing the fish in a separate tank full of fresh water and withholding feed.....for up to 8 days. You don't have to replace too much water because as the fish empty out, they produce decreasing amounts of ammonia.

High nitrate levels have also been suggested as a possible cause of "off flavours"......a good reason for managing nitrate levels.

Gary

[Jason Palenske]

I went just searching a little and found these tidbits in regards to general trout environmental preferences. This is from the Newfoundland Governmental Evironmental Agency.

Rainbow Trout
Onchoryncus mykiss

Status
Introduced to the north-eastern
portion of the Avalon Peninsula from California
in 1887. They currently occupy the Avalon Peninsula,
with populations occurring as far west as Clarenville.

Habitat
Prefer more open and fast water compared to Brook Trout, and can tolerate temperatures between 0 to 25oC. Adults in lakes prefer 18oC. Their preferred lake depth depends on oxygen levels and temperature.

Food
Plankton, crustaceans, insects, snails, leeches, fish and fish eggs.

Appearance
Highly variable in colour: steel blue, yellow-green or brown above, silver to pale yellow-green below; pink to red stripe on sides (except in sea run form).

Breeding Biology
Unlike other trout found in Newfoundland, rainbows spawn in the spring. Preferred spawning sites are fine gravel beds in riffles above pools. Females dig redds, or pits, while attended by several males, but one male is usually dominant. Egg development depends on local conditions, but eggs will usually hatch in seven to eight weeks, and require an additional three to seven to absorb the yolk sacs before becoming free swimming.

[Jason Palenske]

And some extra info you Aussies may find extremely interesting.

http://www.aquaculturecouncilwa.com/species/trout/culture

[Jason Palenske]

Another helpful read

http://www.fish.wa.gov.au/docs/frr/frr130/frr130.pdf

[GaryD]

Hi Jason,

Thanks for drawing out attention to those documents.....both very useful to aspiring trout keepers.

One of the things that I took from both documents was that, for optimum growth, water temperatures should be maintained below 20 degrees C.

I noticed that growth tapers off very quickly once the temperatures exceed 20 and that increased mortality is likely once you exceed 25.

Gary

[Outbackozzie]

They definately go off the food over 20 deg c - thats why its not worth keeping them to try and get more size.

On average my water temp would stay below 25, but every now and then it will go over during summer.

Too much risk, for very little gain.