What causes my wine to be bitter?

[Snafflebit]

Tasted the GW Cab again last night and it is becoming a nice wine. It is obvious that aging helped. I can taste subtle seed tannin bitterness after I have had a couple of glasses, towards finishing the glass. Probably more of a flaw than a fault, IMO. It seems that it takes a little time for that bitterness to build. And I believe the Tannin Riche plays a role in masking that at the start. Hopefully I can report back in a year with even better results

I have started to test homemade and commercial wines, to know what their pH and TA are. The pH is rising on this wine. 3.63 before press (probably affected by CO2), 3.85 last year and now a solid 3.90 pH. I am finding that dissolved CO2 will lower the pH about 0.1 from true pH. My taste prefers the 3.8pH range to the 3.6pH or lower range.

TA is 6.2 g/L. and happy with that

 

[tmcfadden932]

If MLF is complete then it’s ok to add sorbate and Kmeta. If MLF is not complete the Kmeta will produce a geranium flavor.

It's the sorbate that causes that.

 

[tmcfadden932]

Tasted the GW Cab again last night and it is becoming a nice wine. It is obvious that aging helped. I can taste subtle seed tannin bitterness after I have had a couple of glasses, towards finishing the glass. Probably more of a flaw than a fault, IMO. It seems that it takes a little time for that bitterness to build. And I believe the Tannin Riche plays a role in masking that at the start. Hopefully I can report back in a year with even better results

I have started to test homemade and commercial wines, to know what their pH and TA are. The pH is rising on this wine. 3.63 before press (probably affected by CO2), 3.85 last year and now a solid 3.90 pH. I am finding that dissolved CO2 will lower the pH about 0.1 from true pH. My taste prefers the 3.8pH range to the 3.6pH or lower range.

TA is 6.2 g/L. and happy with that

PVPP is not commonly used in red wines, however, it can reduce bitterness and brighten the colour. In many cases PVPP can also reduce certain off-flavours and bitterness. Preparation of 10 % w/v stock solution for laboratory fining trials Add 10 mL of 96 % ethanol to about 80 mL of distilled water. Add 10 g of PVPP.

 

[Snafflebit]

PVPP is not commonly used in red wines, however, it can reduce bitterness and brighten the colour. In many cases PVPP can also reduce certain off-flavours and bitterness. Preparation of 10 % w/v stock solution for laboratory fining trials Add 10 mL of 96 % ethanol to about 80 mL of distilled water. Add 10 g of PVPP.

Ah thank you. That will make bench trials easier.

 

[Hazelemere]

I am starting to get organized for bottling 2020 Cab and Merlot and did a sampling of carboys with friends. I noticed a bitterness on the back end of my wines that I did not seem to notice before. I guess that bitterness comes from seed tanins. I am fermenting on the skins to 1.004 SG, so almost to dry. I have recently learned that some winemakers press as high as 10 Brix. So, that is a technique I am considering for future vintages. But also I have 3 ounces of French oak cubes per carboy. I also use enological tannins. Do those create bitterness?

you can pull out excess tannin with egg white

 

[Rotundifolia]

This year I tried 2 different things. délestage as Winemaker81 suggested (and cold soak). I just tasted the wine after MLF was complete and what a difference that made. There was no tip of the tongue bitterness. Just good tannins. I’m definitely going to do both going forward.

I delestaged on day three when a lot of the seeds were separating out and enough CO2 was in the wine/must for protection. Additionally, I wanted to do this before there was too much alcohol which helps pull the tannins.

What I did was get another brute trashcan and then used a pitcher to scoop off the cap and then the wine. When I got to the bottom where most of the seeds were I used a “gold mining” tool and pored the rest of the juices though this and it capture a LOT of seeds but not all. It required two people but you could use a 5 gallon food grade bucket from a farm or tractor store. It fits perfectly on this. So you could strain it into the 5G bucket and pour it into the brute. Also this technique can be used when pressing to get all the wine with very little seeds.

SE 13 1/4 Inch Stackable Classifier Gold Prospecting Pan - 1/8 Inch Stainless Steel Mesh Sifting Pan, Green​

https://www.amazon.com/SE-GP2-18-Pa...Sifting+Pan,+Green&qid=1698596107&sr=8-2&th=1

 

[Rotundifolia]

Based on all the I learned about micro-oxygenation, I purchased a 15G eco flex tank. I have noticed that the SO2 was low, much more than normal. I know that initially more SO2 becomes bound early on and you need to add 30% to 50% more initially to compensate for the amount that becomes bound. However, the wine was low after frequent monitoring. I initially thought my 10% SO2 solution was off. andI made a fresh batch and still had lower than expected so2. So I reread the section on sulfur dioxide from Daniel Pambianchi Modern Home making. It states “Increase the frequency to once a month for wine aging in barrels and “breathable” HDPE tanks given the greater consumption of FSO2 due to oxygen ingress into these types of containers.”



I also learned that acetaldehyde is highest concentration at the end of AF and takes about 3 days to metabolize. Since the acetaldehyde binds with So2.So you want to make the first addition 10 days to 2 weeks after completion of AF and MLF to reduce the amount of total SO2 added in red wines. (earlier for whites)