Q: late extract addition

When it comes to late extract addition, I've read that 25% of extract goes in at the beginning to aid in hop utilization, and the rest of the extract goes in at the last 15mins of the boil.

My question is: when you add the extract (DME) you obviously cool the wort in the kettle considerably, which then requires ~10mins to get back up to boil (on the stovetop).

Do you factor this "downtime" into the boil process? That is, once DME is added do you wait until the full boil has been restored before resuming the countdown for the last 15 mins?

Interested to hear answers- on my last batch I tried doing a late addition for the first time. I added it gradually during the last 35 to 15 minutes, slow enough it never completely lost the boil. Interested to see if it actually makes any difference.

Not sure how big a difference it makes, but I always wait until the wort is boiling again before I restart the timer. I'm sure during the hot-but-not-boiling "downtime", alpha acids are still isomerizing so bitterness is still being added, and other hop compounds are being volatilized, but I have never done a controlled experiment to see if it had a noticeable effect

When you pol your pot off to add your extract, stop your timer. After you've added your extract and put the kettle back on the burner, when you see the boil start then you restart your timer. I either add my late extract addition at flameout or try to time it so when the boil starts up again it's time to add my last hop addition.

Usually I do it at flameout. The wort is hot enough to pasteurize the extract and that's all it needs.

So CheshireCat...if you do it at flameout, are you letting it sit for a bit before cooling, or cooling ASAP. If the later, is the 10-15mins from boiling temp to pitching temp enough to pasteurize?

10-15 minutes at 170+ degrees is plenty of time for pasteurization to take place. It might actually be 160+, now that I think of it. Either way you're good.

EDIT: To give another opinion on your original question. Yes, boil time is just that...time when the wort is at a rolling boil. Typically I either add it slowly enough that it won't stop the boil or I stop the timer until the boil resumes.

I add it, stir until it's completely mixed in and then start cooling. Now, I cool in a water bath in my sink so it's taking a little bit of time to get it down below pasteurization temps. If you have a faster cooling method, you might give it a few more minutes if you're worried. I'm generally not. I figure that my LME has been sitting at room temp for days and is a perfect growth medium for bacteria and wild yeast. If there was something in it, it would've started working on it already and I'd see some evidence.

I agree with the "add remaining extract at flameout" method. my "cooler" is an icebath in the sink too, so it takes a few minutes to cool down to pitching temps. I have never had any problems with this approach *knock knock* and I have about 10 batches under my belt