Excellent, Eyelusion! You're well on the right track, IMO.
Apropos seemax's qry will it be too sweet with that much malt extract, the Cooper's
APA can comes as 340IBU raw, so 340IBU/kg *1.7kg / 23litres ~= 25IBU. Remembering too that there are different methods for working this out, however that's the one I've been using. To answer the question, I'd do it, but that's just me and my personal preferences.
In fact, I've recently done one with just 1.25kg light dried malt extract and it is reasonably ok, it would be quite similar to what Eyelusion is doing with this proposed brew. [Has another sip...] Yep, it passes! There's a reasonable malt/bitterness balance, I was light on with the hops, but I feel this can needs some steeped hops at either secondary or a few days before bottling if it is just done in primary.
A friend suggested that there's a slight purfume about it that is a tad undesirable, I agree and more flavour and aroma hops do knock it out, so keep that in mind. It does get a bit expensive though with teabags (here they're 5 clams a piece, for a measly 12g), so I'd suggest getting a bigger pack of Cascade for this operation (some suppliers will sell you a 90g pack for less than 10 clams, plus postage).
Let us know Eyelusion if you need info on how to get the extra hops into it, there's a few different ways. Oh stuff it, I've got nothing much better to do, so here goes:
1) Boiling method: Boil up about 4 litres of water with 400g of the malt extract (not the APA can), throw in say 15g of Cascade (or another flavour hop- suggestions welcome of course, and seemax's PoR would be good here), leave to slowly boil, i.e. just rolling, after 15 minutes throw in another 15g of Cascade and allow to continue to boil for another 5 minutes, so it has been 20 minutes since you added your first hop addition. Depending on your hop strength (%alpha acids) his should add another 6 or so IBUs, so it'll still quite OK in my books and well worth it. While this boiling is happening, tip the APA tin and remaining malt extract into your fermenter, when your boil is finished, use it to rinse the cans into the fermenter, but remember to keep it all scrupulously clean, once all the malt and boil is in the fermenter, stir it well with a well- sanitised spoon/ stirring stick to dissolve it all. Add cold water to make up to your 23 litres, ferment & then bottle as usual.
2) Steeping method: Put your brew on as you have done before, you'll need a fair bit of hot water to dissolve the two tins of goop though. Let it ferment as usual, when you think the specific gravity readings are getting close to stable, steep at least 20g of Cascade in about half a litre of boiling water in a well- sanitised coffee plunger or similar, let it sit for half an hour, open up the fermenter, tip it in, close it up, bottle when ready as usual. Steeping is a good opportunity to add gelatine finings as well, that APA can and malt will probably benefit from it if you appreciate clarity in pales. If you do this though, make sure you dissolve the gelatine well before the adding the hops, or just do them seperately. I've tipped one of these combined hop/gelatine brews into the fermentrer before and then discovered most of it stuck to the bottom of the plunger. :angry:
If the loose hops in the fermenter bother you, put them in either a hopbag or a piece of nylon stocking, either in the boil or the steep. I put my brews into secondary most of the time, the majority of the hop debris is settled out before bottling, particularly with the coffee plunger method and gelatine finings. You could even do both methods on the one brew, it would be pretty hoppy, but whatever floats your boat!
The wet teatowel will help, so will a few frozen bottles of water placed around under it if it warms back up much there in the big smoke.
Anyway, damn- there's another epic essay. Sorry about that folks, a thousand pardons... Drop us a line if you have any problems or questions, Eyelusion.