# effect of pre-heat on brewed coffee



## dsc (Jun 7, 2013)

Just tried this on the Sowden as I was getting very bad tasting brews over the last few days. I had a thought it might be brew temp related, but only just got around to measuring the brew with a TC all the way throughout. So on the last brew I've filled the pot with almost a litre of boiling water, left it for a minute and touched the sides, damn that thing's got no insulation, I've almost burned my hands as I wasn't expecting so much heat to radiate to the outside. Anyways I've emptied the thing, dropped some coffee in, TC in and poured off the boil water in, 500ml or so. The first thing that got my attention was the start temp, this was 92degC, which dropped to 89degC after 4 minutes and 80degC after 9minutes. This was all with a super hot pot and still I only got 92degC on the start! mad me thinks. Finally got some nice fruity notes on this SQM bean, although I need to grind a bit finer.

So, what's your preheat regime? re-think what you do, cause you might as well be brewing at 80degC or less and not getting anything good out of your coffee.

T.


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## MWJB (Feb 28, 2012)

Large Sowden (1240g) water straight in 30s off boil, coffee added at a little over 90C. Smaller Sowden (

Steeped brewers that maintain a high temp make it easier to ruin your coffee.

80C is pretty hot for drinking, I guess if you have a minimum temp that you don't enjoy coffee below, then monitor & drink at that temp, I'm happy to let Sowden & FP steep until at drinking temp (55-60C?).


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## dsc (Jun 7, 2013)

How are the temps measured and where? have you measured temps within the brew throughout the brewing process?

80degC is too hot, I wait till 50-60degC to drink.

T.


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## MWJB (Feb 28, 2012)

Temp probe down the spout. I don't see the point of continuous measurement...just start & temp when the flavour peaks? If 50-60C is your preferred temp, why not leave the coffee in the pot so it continues to develop until it declines to that temp?


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## dsc (Jun 7, 2013)

I'm not a fan of long brews, that's why.

I've measured it throughout just to see what you get at various stages, especially on the start. If I get 92degC with a pipping hot pot, I wouldn't get above 90degC if I simply added off-the-boil water to a cold pot. If your start temp is off, there's not much point it leaving it in the for longer imho.

T.


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## MWJB (Feb 28, 2012)

Steeped coffee continues to extract even as the temp drops (not opinion but fact, as long as your grind is condusive - most important factor), so to hit a desired extraction, if you start a little low, you have to leave longer.

Even starting at 92C it takes me 50-70 minutes to hit my (but not the only) preference at 22-23%. Depends on pot (820g seems faster, probably due to volume inside the filter being a bigger proportion of the pot's volume) & grind/grinder.

19-20% immersion yield should still be possible at ~10mins?


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## dsc (Jun 7, 2013)

I've tried pretty fine grinds from the Guat at 10-20min and I was getting piss poor results with TDS hitting 1.1% max.

T.


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## MWJB (Feb 28, 2012)

What brew ratio?

I'm usually aiming 1.15% to 1.20% ~54g/l.

If you want a shorter brew time then maybe 67-75g/l to get over 1.2%. I think the fineness of the filter retards the brew time over FP.

I'd go as fine as you dare & judge by silt evident in the cup (bitterness, or pruney flavours, will probably hit these before you can feel anything in the cup) & dregs in the last bit left in the pot. From my records, I have had great cups as fine as 0.63 turns on a Lido1 (espresso range is quoted at 0.25 to 0.75), average grind setting 0.9 of a turn (Lido1 is bimodal here, from OE's grind analysis 60-65% passing through a 850um sieve).

Tried the ZR with it?

Discard the first quarter to half a cup of any brew.


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## dsc (Jun 7, 2013)

I tend to go with 60g/l, never tried updosing to be honest. I'm waiting for the ZR to go operational again and I will give this another go.

The other problem I'm struggling with is stomach reflux, it tends to kick in after a few sips of coffee (I really shouldn't be drinking it at all ) and doesn't make tasting easy or pleasant.

T.


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## MWJB (Feb 28, 2012)

If you're brewing at 60g/l then 19.5% immersion yield comes in at 1.11%TDS.

The reflux sounds like a bind, sorry to hear about that. I guess if you shouldn't be drinking coffee at all, then there's not much practical advice that will help, but...if you are going to persevere, try 53.5 to 54.g/5l at whatever time it takes you to hit 1.15%TDS+. If your start temp isn't too high, you'll get a less acidic cup. Might not be as bad in that respect...?


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## dsc (Jun 7, 2013)

I'll give it a go next week when the ZR is up and running. I'll have the Cremina as well at that point probably, so can do some tests with espresso and see how that abuses my stomach.

Reflux timing couldn't be better, just when I got the grinder finished nasty stuff though, had a cough for 3 months due to it and thought it's a chest infection.

T.


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