Temperature and Repitching on Yeast Cake

This weekend I plan to brew an oaked bourbon porter. I currently have a Texas Red from AHS that will hit three weeks in the primary this weekend. I plan to bottle it before brewing my porter. I used White Labs Dry English Ale (WLP007) for it. I would like to re-use the yeast cake from the red for the porter but I have never done it before. I am probably over-thinking it but I figured I'd ask anyways.

1) After three weeks of sitting in the carboy is the yeast cake still good to pitch on to?

2) My main concern is with the temperature of my wort when I rack it on to the yeast cake. I do partial boils and usually end up with 3 gallons of hot wort. My normal procedure is to cool my wort down to about 110-120 degrees using my sink and an ice bath. I then pour two gallons of cold water into the carboy and mix in my three gallons of hot wort. This gives me wort that is about 75-80 degrees. Would I need to mix the cold and hot liquids in another container and then rack on to the yeast once its cooled down or is it ok to go with my normal procedure and rack it directly on the yeast cake?

Thanks.

1 the yeast is fine


2 I would try my best to lower it some more in the ice bath.

I almost always pitch in the mid/upper 50's for ales

Your beers will thank you if you pitch low and let the temps come up slowly

1) Yes yes yes. They're waiting for you.

2) Probably best to use a seperate vessel. Blend with your cold water, get your 75 degree wort, then pour that into your carboy with the yeast cake. You'll get extra aeration from the second pour, consider that a bonus.

Or, another way to tackle this... pour in about 1 qt of your cold top off water into the carboy with the yeast cake, and pour the rest into another carboy with your wort as normal. Swirl the yeast cake up really well with the 1qt of cold water you added, then pour the yeast into the new (clean) fermenter with all the wort in it.

I like to pour the wort onto the yeast cake, though, because it gives me pretty decent aeration for the whole batch.

+1 to jim, I would chill this batch a little further in the ice bath, before you start with the top-up water. With an active yeast cake, ideally you'd want to be around 60*F and come back up.