When to Press???

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winemaker81

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@SLM asked pertinent questions regarding pressing in @crushday's thread Last Grapes of The Year ...

Instead of muddying his thread with a lot of technical discussion, I'm starting a new thread.

I don't have much experience and your journey raises some questions for me.
Why did you press some grapes before they went dry? Is that timing critical? Why do you separate into free-run and then two pressings? Why do you want a gentle press?

Experienced folks can chime in, describing what they do and why they do it. Questions are encouraged!
 
Pressing is a complex topic, a mix of science and art. There are many choices that produce different desired outcomes.

Get a glass of wine (maybe 2) before continuing -- this is a long post!

When to press? The longer the fermenting wine has contact with the pomace, the more constituents it extracts from the pomace. To produce a heavier, fuller bodied, and more tannic wine -- press after fermentation ends. I've heard of folks leaving the pomace in the wine for weeks after fermentation to get the most body.

I prefer to press when the SG is 1.000 or below, but fermentation not complete. The cap is still solid so I can rack a lot of the free run wine from beneath the cap. This means I put less "stuff" in the press, e.g., less labor.

People press at higher SG as the heaviest wine is NOT necessarily the goal. Also, free time matters e.g., it's Sunday, the SG is 1.010 and I will be working 12 hour days until Friday. So I'm pressing today.

Free run wine has less harshness than pressed wine and can have a "cleaner" aroma and flavor. It also has less aroma, flavor, and body. Hard pressed wine has more of everything, including a harshness, so it's a trade-off. Some folks age the free run and pressed wine separately, and blend in some of the pressed wine into the free run to increase body without increasing harshness too much.

For 2020, I have one barrel that is 2/3 Merlot, 1/3 Vinifera Blend (Cab Sauv, Cab Franc, Malbec, Petit Verdot), all free run. The second barrel is 40% Merlot, 40% Zinfandel, 20% Vinifera Blend, all medium press. Beyond the difference the Zin makes, the wines are clearly different. [I like experiments and can seriously complicate my wine making life by getting deeply into things.] I'm pleased with both so far, as they give me an interesting variety in the cellar.

NOT pressing throws away a lot of wine. I produce a 2nd run from the pomace, adding water, sugar, tannin, and acid to produce about 50% more wine -- wine that is lighter in color, aroma, body, and taste -- and ages quicker. "2nd run is what ya drink while the 1st is aging"

Last October I added 15 gallons of water + sugar/tannin/acid to the pomace from 16 lugs of grapes. When I pressed it, I got ~20 gallons of wine, meaning that the "medium" press I did for the 1st run left 5 gallons of wine in the pomace.

In 2019 I divided the press for the 2nd run into 2 parts -- 15 gallons of "medium" press and 7 gallons of "hard" press, where we cranked the press hard to get what we could from it. The 2 wines are very different, and I used some of the hard press to top up the 1st run wines, even as a 2nd run it had more body than the 1st run (not a lot, probably 1 bottle/carboy).

The medium press spent 10 months in a neutral barrel with 6 oz Hungarian oak (~3 months), while the hard press received no oak. The 2 wines are so different no one believes they are the same wine.

Two years from now it will be interesting to taste the 2019's and 2020's side-by-side to compare and contrast.
 
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I think that this thread is really important because it touches on the pros and the cons. I have only (to date) made grape wine from fresh grapes once (and that was this fall) so my experience is about as deep as my knowledge but I would suggest that the length of time you want to allow the wine to sit on the skins and seeds a good rule of thumb might be to reach out to wine makers who routinely make the wine from the grapes you have crushed. I have no stake in this but this "reaching out" might be as simple as checking what journals such as WineMaker magazine. In each issue they include one article focused on wine from one grape varietal and in their "step by step" they suggest the length of time to allow before pressing.
 
Not arguing the whole carbonic maceration thing, but enzymes up front, get most of that body and color out, without risking the whole fermentation to infection by holding off the press after it's done. I've only used Lallzyme EX and EX-V but there are many others.

I like to press at 0-1 Brix. That way it's still fermenting just a bit in the receiving vessel. I think it tends to displace the minimal head space of O2. Practically speaking, it finishes 1-2 days after press, and then gets racked off the gross lees. But with that said, I've actually made more press decisions based on practical factors in my life-like I need to press today because I'm working the next 7 days in a row. Or, it's a 1 Brix now, but tomorrow I have a block of time to knock this out.

Regarding "hard" or "soft" of press, that's a pretty slippery term. You need to define that. I've played around with pressures a bit and press to 1 bar typically on the bladder press. I think that would be considered a "soft" press, but in my own experiments, there is not much wine left in the skins above 1 atm. In prior years, I've pressed 1.5-2 Bars.
 
Enzymes are a significant expansion on this topic. That deserves a thread of its own. I used enzymes for the first time in October and I'm eager to learn more.

I wish I could define "soft", "medium", and "hard". I have a #40 basket press -- a light press is turning the handle until it it takes effort to turn. Then it's medium until I have to put some real muscle into it. Hard ends when we can't turn it more. I have no way to measure the actual pressure.

For beginners, it may be that "soft" and "1 bar" mean equally little. Without more background in bladder presses, "1 bar" doesn't mean anything to me, either. Not that I'm arguing against accurate descriptions and measurements; rather I'm leaning towards basic descriptions, to get people started in learning about pressing. The real question is if we can do that.
 
I too like to press right around 0 brix, but often times logistics determine when I press more than getting to 0. Meaning, if I have a ton (2,000 pounds) of fruit to press and help is available on the weekend and the must is at .5 brix, guess what we are doing on Saturday. I will also let the must sit for a couple days past 0 brix, if it works out better logistically. I will also look for earlier pressing on varietals that tend to be high on tannins (Petite Sirah) and try to stretch it on those varietals I'd like more extraction (Grenache).

I have separated my pressings the past two years and found that with the style of wine I like to make (fruit forward, soft tannins, smooth finish) benefit from having a higher percentage of free run. I don't toss the pressed juice (it is a soft pressing at 1 bar), but rather keep it separate and make another wine, usually a different blend.
ferm temp.jpg
 
I wish I could define "soft", "medium", and "hard". I have a #40 basket press -- a light press is turning the handle until it it takes effort to turn. Then it's medium until I have to put some real muscle into it. Hard ends when we can't turn it more. I have no way to measure the actual pressure.

For beginners, it may be that "soft" and "1 bar" mean equally little. Without more background in bladder presses, "1 bar" doesn't mean anything to me, either. Not that I'm arguing against accurate descriptions and measurements; rather I'm leaning towards basic descriptions, to get people started in learning about pressing. The real question is if we can do that.

1 Bar = 1 ATM = 14psi so it's pretty easy to visualize what is meant. In looser terms, 1 Bar means fairly dry skins, 2 bar, very dry skins etc. Clicking the ratchet on a basket press, there is no way to define hard vs soft. How long is your lever?

I did an experiment this year-Pressed a full press load to 1 Bar, then increased to 2 bar. It only yielded another 500 ml of wine-so not much. My bladder press has a pressure relief at 2.5 bar, so that's the upper limit. But 1 Bar is my defacto standard press.

But I thought this was supposed to be about when to press. And when to press is pretty easy. For most of us, it's at the end of fermentation, at least for red grapes. You get a day or two as a fudge factor in home wine making but not much more. Now with professional equipment and refrigeration, you would have a lot more leeway to delay your press.

Interesting thought @NorCal about making a different blend with the press wine. I put my press and free run together, but could see trying your method next season.
 
So is this topic about when to press RED wine only? Because all comments seem to be about red wine. Not clear from the title.

If so, should white wine makers like me give advice on white wines (as there are also options with white wine that can vary, but of course under shorter time frames unless one is making an amber or orange wine).
 
1 Bar = 1 ATM = 14psi so it's pretty easy to visualize what is meant. In looser terms, 1 Bar means fairly dry skins, 2 bar, very dry skins etc. Clicking the ratchet on a basket press, there is no way to define hard vs soft. How long is your lever?
This description gives me a rough method of judging by appearance, which I had not thought of. It appears that what I'm calling "medium" is roughly 3/4 to 1 bar, and "hard" is 2-ish. "Light" is probably 1/2 bar.

Hopefully this will help those that don't a press that has a pressure measuring mechanism built into it.

The different pressings taste different. As I mentioned above, one barrel has only free run wine and it tastes very different from the pressed wine. I had no intention of separating the wines, but I got part way into pressing and I decided to do a barrel of free run separate from everything else.

At that time I also decided the free run barrel would be a Meritage (Bordeaux style) wine, while all the Zinfandel would go into the other batch. It would be simpler to just do it all together, but I like the idea of having 6 cases of one wine and 8-10 cases of another, plus 8 cases of 2nd run. It gives me variety.

But I thought this was supposed to be about when to press. And when to press is pretty easy.
That is very true. If we stuck to "when" the thread would be a very short one. Adding in "how hard" expands the topic in a useful direction, as that's the 2nd question a newbie to fresh grapes would ask.
 
So is this topic about when to press RED wine only? Because all comments seem to be about red wine. Not clear from the title.

If so, should white wine makers like me give advice on white wines (as there are also options with white wine that can vary, but of course under shorter time frames unless one is making an amber or orange wine).
Pressing white grapes never crossed my mind when I started this thread. However, I foresee good discussion on this topic, so I started a separate thread for pressing white grapes.
 
Helpful info, thanks. So I assume you can immediately taste the harshness of the pressed wine? Or more so with time?
i don’t think our home winemaking equipment has enough power for us to notice much difference. i have pressed hard af at times and noticed no difference. i even kept press and free separate often just because the amounts worked out that way with my vessels. 300lbs normally get a 15gal demijohn of free and 5 or 6 gal carboy of press.
and actually at first the press wine tastes better to me. I assume since it gets all that extra o2.

normal schedule for me:
Saturday pickup fruit & crush
sunday night yeast
saturday press.

too much work & cleanup to press on a weeknight imo
 
@SLM, I don't initially notice any difference other than color, and color is tricky as there are a lot of solids floating in the wine. A month or two after tasting I noticed a difference in taste -- IME the hard press has a bit more body. It may be that I'm noticing this because I'm tasting the 2 wines against each other, looking for differences. If I tasted one now and the other 20 minutes from now, I may not perceive a difference.

Tasting my 2019's, I wish I had preserved a few bottles of the medium pressed wine, unoaked, so I can compare apples-to-apples with the hard pressed (unoaked). There are differences that the oak does not account for, but I don't trust my palate to adequately describe the differences. I can say that a harshness I tasted in the hard press a year ago is not present when I opened a bottle last month, so it mellows with age.

The 2020 1st run will be a better test, as the free run and the pressed are in different barrels, and will receive the same oak. Unfortunately the blends differ, making the comparison more difficult. Fall 2021 I'm currently planning a Rhone blend, no Zinfandel, and intend to do a single blend with free run in one barrel and pressings in the other. A year from now I'll be able to comment.
 
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