"Second Cup" Effect

[Mjx]

Ever since we've had the Silvia, my boyfriend and I have noticed that the second round of coffee tastes better than the first; the first cups are fine, but the second are inevitably better. We hypothesized vaguely about the phenomenon, but didn't dedicate that much thought to it. We doubted it was the temperature, since we've noticed this even when the machine warms for about a quarter of an hour.

Turns out, it may be the temperature after all.

Yesterday, I picked up some coffee beans at one of the few independent local coffee shops that roasts its own beans, and spent some time chatting with the owner, who's American (meaning, I actually understood the conversation, since it wasn't carried out in a language in which I routinely confuse the words for 'cow' and 'queue'). I mentioned the thing with the first cup of coffee from our machine not being as good as subsequent ones, and he said that this is usual with most machines, consumer or commercial. His idea is that during the intial heating, the machine actually gets too hot, and using it brings lowers the heat to just the right temperature, but the first cup takes the bullet, so to speak.

This makes sense to me, although I'm not equipped to test this: Anyone else notice this 'second cup' effect, or have data/alternate hypotheses?

[bmdaniel]

The phenomenon/technique is known as the heating flush and is a well-known issue on heat exchanger machines like the Silvia. Good article here:

http://www.home-barista.com/hx-love.html

ETA: remembered that the Silvia is not an HX but a single boiler - I think the phenomenon is similar though - here is a Silvia specific article: http://home.surewest.net/frcn/Coffee/Coffee58.html

Edited May 3, 2012 by bmdaniel (log)

[earlgrey_44]

Turns out, it may be the temperature after all.

This makes sense to me, although I'm not equipped to test this:

Oh, yes you are equipped, oh person of good taste!

Pulling espressos at the correct temperature for the coffee you're using - and doing it consistently - is a bit of a challenge on a single boiler machine like Sylvia. Temperature variation is one possible explanation for the "second cup better" experience.

Test it this way: sip the first espresso straight. Do the same for the second pull. If the first taste tends toward being overbearingly bitter, while the second is noticeably more balanced and "sweet", that would support the idea that your usage method for Sylvia is causing you to pull the first shot too hot, since too-hot pulls tends to make the bitter flavor component take over and dominate the other flavors in the coffee. If not, the temp is probably not your problem.

The other popular explanation for "second cup better" has to do with the effect of stale oils in the machine or, conversely, the absence of fresh coffee oil seasoning. The first shot of the day will dissolve any stale oils (into your drink) and refresh the metal surfaces with new coffee oil. The second pull thus benefits. With practice, it's possible to distinguish between stale flavor and fresh, but off-balance bitter or sour flavors, though this can be confusing if you have not had had much experiment time playing with the machine. If you're not sure you're covered here, do a little reading about cleaning best practices and see where you stand.

Some folks swear that a scrupulously cleaned machine will do some evil to the first shot, and the fresh oil will bless the second, but many others say this is silly and they notice no difference between the shots when the machine starts off clean (and they have learned to control the temp).

Edited May 3, 2012 by earlgrey_44 (log)

[nickrey]

Get yourself a pid controller. The problem will go away.

[jmolinari]

It may not be temperature. The 2nd cup effect can be attributed to the coffee oils baking on the machine overnight from the last shot teh previous day. Those oils are flushed out with the first shot. The 2nd shot is therefore cleaner.

http://www.home-barista.com/tips/sink-that-first-shot-t12451.html

[goodkidwe]

It may not be temperature. The 2nd cup effect can be attributed to the coffee oils baking on the machine overnight from the last shot teh previous day. Those oils are flushed out with the first shot. The 2nd shot is therefore cleaner.

I agree with that. coffee oils make the second coffee more tasty.

[David A. Goldfarb]

Do you have grounds that stay in the grinder, drying out and getting stale, to be pushed out by the new grounds when you grind the next batch? I found this to be the case with my grinder, so now I keep a wooden skewer next to the grinder to dig the grounds out from the grinder spout for the last espresso I make in a batch. If you have a doser, that's also a place where coffee can sit, getting old between batches.

[jmolinari]

It may not be temperature. The 2nd cup effect can be attributed to the coffee oils baking on the machine overnight from the last shot teh previous day. Those oils are flushed out with the first shot. The 2nd shot is therefore cleaner.

I agree with that. coffee oils make the second coffee more tasty.

Uhm..no. The opposite. The oils that baked overnight make the 1st cup worse than subsequent cups.

[Shalmanese]

In that case, why not make the first shot with water and see if the 2nd shot is still better or not.

[jmolinari]

In that case, why not make the first shot with water and see if the 2nd shot is still better or not.

True, or a quick backflush before pulling the 1st shot.

[Mjx]

The phenomenon/technique is known as the heating flush and is a well-known issue on heat exchanger machines like the Silvia. Good article here:

http://www.home-barista.com/hx-love.html

ETA: remembered that the Silvia is not an HX but a single boiler - I think the phenomenon is similar though - here is a Silvia specific article: http://home.surewest.net/frcn/Coffee/Coffee58.html

Thanks, I'm going to be reading that in a bit!

. . . .

Pulling espressos at the correct temperature for the coffee you're using - and doing it consistently - is a bit of a challenge on a single boiler machine like Sylvia. Temperature variation is one possible explanation for the "second cup better" experience.

Test it this way: sip the first espresso straight. Do the same for the second pull. If the first taste tends toward being overbearingly bitter, while the second is noticeably more balanced and "sweet", that would support the idea that your usage method for Sylvia is causing you to pull the first shot too hot, since too-hot pulls tends to make the bitter flavor component take over and dominate the other flavors in the coffee. If not, the temp is probably not your problem. . . .

The first cups tend be thinner, but aren't usually unbalanced (unless the beans themselves are; the first cups do tend to emphasize any shortcomings of the beans).

Get yourself a pid controller. The problem will go away.

I've toyed with the idea, although I can't really describe the situation as being at the level of 'problem' (the first cup is fine, but the second is better), more 'excuse to drink multiple cups', so I've held off. So far; if I want to eliminate the problem altogether, you're probably right, this going to be the way to go.

It may not be temperature. The 2nd cup effect can be attributed to the coffee oils baking on the machine overnight from the last shot teh previous day. Those oils are flushed out with the first shot. The 2nd shot is therefore cleaner.

http://www.home-barista.com/tips/sink-that-first-shot-t12451.html

Don't think it's that, since this happens regardless of whether the basket and holder have been scrupulously cleaned, left with the grounds sitting until we use it the next day, or any of the various options between the two extremes.

Do you have grounds that stay in the grinder, drying out and getting stale, to be pushed out by the new grounds when you grind the next batch? I found this to be the case with my grinder, so now I keep a wooden skewer next to the grinder to dig the grounds out from the grinder spout for the last espresso I make in a batch. If you have a doser, that's also a place where coffee can sit, getting old between batches.

The grinder is regularly brushed, poked, and tapped free of loose grounds (it grinds directly ito the basket)

In that case, why not make the first shot with water and see if the 2nd shot is still better or not.

Actually, we tried that! And, the pattern seemed to persist. It isn't a huge deal, but I do find it kind of interesting, and have been wondering what lay behind this phenomenon .

[scubadoo97]

I usually toss my first shot which is used as a test for grinder setting

[David A. Goldfarb]

Maybe the first cup prepares the palate for the second. Perhaps you should befriend an accounting, real estate, or insurance firm in your neighborhood and collect the leftover coffee from them at the end of the day, leave it out overnight and warm it up in the microwave the next morning, and then after this spectacularly bad first cup the second cup will be even better.

[earlgrey_44]

The first cups tend be thinner, but aren't usually unbalanced (unless the beans themselves are; the first cups do tend to emphasize any shortcomings of the beans).

"Thinner" ? Hmm... doesn't sound like a temperature problem, really. If it's not temperature, a technofix PID will certainly make the machine easier to use but won't help the issue.

... this happens regardless of whether the basket and holder have been scrupulously cleaned, left with the grounds sitting until we use it the next day, or any of the various options between the two extremes.

Careful now. Nobody said it was oils in the basket and holder that caused an off taste in the first cup - it's some of the parts behind the shower screen, inside the machine if you will, that's the main concern.

It isn't a huge deal, but I do find it kind of interesting, and have been wondering what lay behind this phenomenon .

Me too. Perhaps you're one of those I mentioned above who like better what an espresso machine does after it has just had a "seasoning shot" than a machine that has not - all else being equal. While it is a more controversial assertion, and I've never read an argument as to why it should be so that really motivated me to change my ways, there are many pros and home baristas that think so. Just because there's no consensus, that doesn't mean it's wrong.

Edited May 4, 2012 by earlgrey_44 (log)

[rotuts]

If you are concerned that your machine in the first or any shot is effecting your espresso, its very easy to test.

get the machine to temp. 'pull' a shot through an empty portafilter in an espresso cup. let it cool to room temp. add the same amount of water from the reservoir to a second espresso cup and when they get to the same temp: taste. Double blind or not, they should taste the same. The 'pulled' shot should at least taste like plain water.

if not, you have some (easy) work to do on the machine.

Edited May 4, 2012 by rotuts (log)