Checking for Tannins

[OtisT]

Howdy. I have some wood I want to check for excessive tannins. I’m looking for help on how best to test for this. Here is what I am doing, followed by some questions.

I have some American Oak air dried for two years, kiln dried, air dried for over a decade, then seasoned outside for a full year. This is my “best” wood and my control.

I have some Oregon Oak air dried for over two years then solar kiln dried.

The test:
I want to see how my OOak compares to the AOak with regards to tannins. From my research, Oregon Oak is considered similar to French Oak with regard to flavoring, grain structure, etc. OOak has more tannins to start with than AOak, and once tannins are reduced it ages spirits and wine like French Oak does.

My test:
I have some 1” square samples of each wood. I split each cube into 4 to 6 slices (chips) each so I know the amount of wood is equal.

I made two 100ml sample jars for each wood sample, using my 60% ABV vodka. I used my vaccume sealer to cause the oak to soak into the wood completely at the start then released pressure. Am vacuuming each jar every few days.

My plan is to blind test sample each of the 4 jars to see if I notice more tannin taste in some of the jars. I believe tannins will come across as bitter.

Questions:
Is there a better way to test this at home? Some form of chemistry method to comparing tannin levels?

How long do you think I need to wait before testing to get the effect of wood tannins?

How do I identify tannins? Is it only a bitter taste, and/or is there a smell component as well?

Thanks. Otis

[Pikey]

Damn - sorry Otis - just did a big reply - and had a power cut for a few seconds which logged me out and lost it !

I'll come back if I can cnvince myself to type it all again !

[SaltyStaves]

Make a tea. Boil the wood in water for 10 minutes then taste it.

[OtisT]

Thanks for the effort Pikey. I hope you fine the energy to share your knowledge. Would love to hear what you know bout this.

Thanks Salty. I will make some tea as you suggested and see how that goes.

I sure hope the Oregon Oak has been seasoned long enough. I got a lot of it and hope it does not need to sit in my yard for a few years before I can use it.

Otis

[Shine0n]

Cut it to size you plan to use in the jars and sit it outside for 6 months in a ss strainer. That should be plenty of release of the nasties.
Do you plan to toast?

[OtisT]

Cut it to size you plan to use in the jars and sit it outside for 6 months in a ss strainer. That should be plenty of release of the nasties.
Do you plan to toast?

I’ve got quite a bit more than will fit in a strainer. I not using injars, but rather for Badmo style barrel heads. I do have the boards stickered outside and have been hosing them down on occasion during this heat to soak then release moisture. If my testing shows too much tannins, I may try a solar kiln type plastic tent over them with a sprinkler inside. Put them through a series of soak/dry cycled during the heat with a fan to move air, and if necessary just uncover during our wet months.

Most will be toasted.

I’m hoping two years air drying will be enough, but will test soon and find out. Making tea today, and will also be sampling the chipped up wood in vodka I started a week back to see what I may notice in those tests. I just realized I have my best seasoned American White oak as a test control, but I should also add some fresh oak to test, to contrast my other samples with.

Thanks for th help. Otis

[NZChris]

How much tannin is too much? Tannins break down the lignins, starting a chain of reactions that make desirable flavors, so cutting them back too much might be a mistake if you are wanting to create aged character in your liquor.

Overly astringent product that I've sampled has been fixed by putting the bung back in and leaving it for another year. My four times over-oaking experiment had lost much of it's astringency and become pleasantly drinkable by two years.

[OtisT]

How much tannin is too much? Tannins break down the lignins, starting a chain of reactions that make desirable flavors, so cutting them back too much might be a mistake if you are wanting to create aged character in your liquor.

Overly astringent product that I've sampled has been fixed by putting the bung back in and leaving it for another year. My four times over-oaking experiment had lost much of it's astringency and become pleasantly drinkable by two years.

I am not really trying to identify “too much” tannins or astringency. I’m trying to understand how much are in my Oregon Oak, relative to my seasoned American White Oak. I am happy with the American White Oak I have been using so I am hoping my Oregon Oak is not significantly heavier in tannins/astringency.

From some research I have learned that Oregon Oak is similar to French Oak with regard to chemical makeup and grain structure, including a lot more tannins, which is why I am doing this test.

Good to know this stuff workes it’s self out over time. Thanks for the info.

Otis

[NZChris]

This might be of help.
http://whiskyscience.blogspot.com/2011/ ... vours.html

[OtisT]

I want to report back in this thread on my tannin comparison test. I decided to use this same wood tea process to asses other wood types I have, beyond just testing for tannins, so the test results below goes beyond the subject of the OP.

Because I want to continue experimenting more with the wood tea making process I plan to start a new thread soon that will start out where this subject is ending for me, so I apologize for the redundancy in advance. Otis


Wood Tea Experiment - comparing Tannin levels and more

From my research I have learned that Oregon Oak (OO) is very similar to French Oak with regard to its use for aging wine and spirits. Compared to American White Oak (AWO) OO imparts a lighter and fruitier flavor/scent on the spirits with the exception of Tannins, which OO and French Oak are higher in. OO and French Oak both require ample seasoning to release these tannins prior to use. OO is also similar to French Oak in it’s physical wood grain characteristics. A short description of one analysis of OO compared to AWO can be found here: http://oregonbarrelworks.com/Oregonoak.html" onclick="window.open(this.href);return false;" rel="nofollow

I have a lot of Oregon Oak that has air dried for over two years and I want to know if it is ready for use in aging spirits. I have decided to compare the OO’s level of tannins with a sample of some seasoned AWO I have successfully used for aging spirits. This part of the test will simply be a relative comparison of tannins between the two woods. With regard to tannin levels, I figure that if my OO it similar to or not much greater than that of my sample of AWO, the OO is ready for use aging spirits.

My understanding is that Tannins are both Bitter tasting and are Astringent in the mouth, so I will be looking for these indicators in my tea. Astringent is not a taste, but is like a skin puckering/tightening feeling.)

I will also be making tea out of four other woods I plan to use for aging. I’m not specifically looking for tannins in these woods, but am simply curious what I will learn about these by making a tea out of this wood. I’m a curious person and this is all just one big learning experience for me.

List of woods to be tested
- Oregon Oak - Quartersawn 1” boards stickered and air dried two+ years before being finished off in a solar kiln.
- American White Oak - Quartersawn 3” boards air dried two years, finished in a kiln, then seasoned outside for 9 months.
- Mesquite- kiln dried, and seasoned outside for xx months.
- Apple - Seasoned outside for 2 years. Heartwood only, hand split into sticks.
- Cherry - Seasoned outside for 2 years. Hand split into sticks.
- Plum - Seasoned outside for 1 year. Hand split into sticks.

Wood samples for the test

Tea Making Process
Wood samples each started as ~1” cubes and were split into small chips.
Bring 3/4 cup water to a boil and add chips
Maintain low boil for 5 minutes and strain (first boil)
Let samples cool and taste
Add another 1/4 cup water (replace liquid from my first sampling) and boil tea with the same chips for another 5 minutes
Let samples cool and taste again

Color after the first boil

Another color comparison, after the second boil

Tannins - Comparing Tannins and more between the two Oaks
None of my samples had any bitterness to them.
Both of my oak samples were astringent.
I noticed the astringency ran down the middle of my tongue and no where else in my mouth. The intensity and duration of astringency was similar, though I found the taste that came along with it to be quite different. Where the AWO seemed richer with more nutty/woody notes, the OO had a lighter more fruity/floral/woody note.

The astringency did not linger long in my mouth for either tea. The main difference in astringency I noticed was that the OO appeared to be more of a focused “bite” closer to the tip of my tongue, while the AWO was more wider and more prominent toward the back of my tongue.
I diluted both samples 50/50 with distilled water. Astringency in both was reduced to barely noticeable, with the same taste profile.
Overall, the AWO was more intense in flavor/smell as compared to the more subtle OO notes.

Based on this comparison of OO to some AWO I know to be good for aging spirits I feel the Oregon Oak is ready for use in aging spirits.

Tasting notes by wood

American White Oak (AWO)
Color. A medium amber color that is much darker than OO.
Smell. Med/light intensity. A distinct smell of oak with Sweet and Nutty notes.
Taste. Sweet, Oak. Richer and thicker feel compared to OO.
Feel. Astringent down the center of my tongue, focused on the back of tongue. A bit more mouth feel/thickness as compared to the OO.
Notes. This helped me with a good baseline on what to expect from an Oak I am familiar with.

OO
Color. A lighter amber color that is much lighter than the AWO.
Smell. Light intensity. A delicate fruity, floral, and nutty smell.
Taste. Sweet, oak. A light fruity taste. Less intense than the AWO.
Feel. Astringent down the center of my tongue, focused on the tip as a brief “bite”. A light/bright feel as compared to AWO.
Notes. This seemed to match with what I have read on the characteristics of a French Oak. I.e. lighter in flavor intensity compared to AWO with an emphasis on floral and fruity notes vs woody/ darker notes. The tannin intensity comparison makes me feel this is ready to use for spirits.

Mesquite
Color. Not much.
Smell. Slight woody smell. Not much.
Taste. Not much.
Feel. Slight woody dryness
Notes. I did not get much from this wood. Not sure how I would use it.

Cherry
Color. Med amber color, touch of red. Almost identical to Apple.
Smell. This has a very prominent fruity and sweet smell that was very strong and noticeable from the get go. I could tell it was cherry immediately.
Taste. A very prominent sweet and bright fruity taste. The fruit taste was stronger and notably different than the fruity taste I got from the Plum. (Both good, just different.)
Feel. Not much. Did leave a slight pucker on one tasting that did not last long.
Notes. I get the feeling that Spirits would not need to be in contact with Cherry long before benefiting from this wood. The nose and flavor is strong enough that it would be identifiable in almost any liquor.

Plum
Color. A rich Red/Amber color. Surprising, because the wood was one of the lightest in color.
Smell. Not very noticeable at first, but with some time sampling I could detect some rich fruity notes that were plum like. Raisins, etc. much more noticeable after the second boil. This rich fruit smell is distinctly different than the light fruity notes coming from the cherry.
Taste. A light sweet and dark fruity taste. Slightly drying to the mouth, but did not linger.
Feel. Not much. A slight drying sensation that did not last long.
Notes. This wood has some wonderful dark/rich fruit notes in it. Less intense than the Cherry

Apple
Color. Med amber color, touch of red. Almost identical to Cherry.
Smell. Not much. A very subtle hint of fruit with the wood.
Taste. Refreshing and clearing the pallet. Not much to it.
Feel. Refreshing. No bit, pucker, dryness, etc. very neutral.

Personal Observations/Thoughts on how I will use this wood
1 - I am looking forward to using Oregon Oak, especially with Brandy and Rum where the floral/fruity notes will be noticed. I think it will go well with some of the more delicate whiskeys where I don’t want to cover too much with a strong oak. (Like the Oat/Wheat/Rye whiskey recipe I am making now.). Oregon Oak aged spirits will not be as dark as AWO aged spirits.

2 - Cherry is a strong wood and should be used either sparingly and/or for a short duration before being checked for impact on my spirits. The fruity notes from cherry are lighter/sweeter flavors as compared to the Plum. I think the nose will be most noticeable when using cherry, with heavier spirits perhaps covering the light fruity notes.

3 - Plum has some wonderful dark fruity notes. ( think raisins, plums). I think it may take more time for the Plum to have an impact on a spirit but the end result should be delicious. I am really looking forward to trying this wood with many different spirit types, especially brandy and whiskey. The dark fruity notes should be wonderful with even a strong whiskey.

4 - Apple and Mesquite. I can’t think of a use for either at this time. Apple had a hint of fruit to it, so maybe a long soak in Apple will eventually add something fruity. I think using either will end up requiring a long soak and will be subtle.

5 - This was a fun and personally rewarding experiment. I plan to toast a sample of these woods and try this test all over again.

Otis

[Pikey]

My understanding is that Tannins are both Bitter tasting and are Astringent in the mouth, so I will be looking for these indicators in my tea. Astringent is not a taste, but is like a skin puckering/tightening feeling.)................

If you have access to elderberries where you are - make an elderberry wine - 3 to 4 lb elderberries 1.75 lb sugar 1 make up to gallon with water (If usa gallons) - lferment on pulp 7 days then strain and ferment to dryness - clear - That will demonstrate exactly what "tannin" tastes and feels like !

In theory if you leave it enough years it will be magnificent ! - I threw it out after 7 years !

However, use the same quantities and just remove the berries after an hour or even less, you will be drinking a red "table wine" by Xmas ! (There are better recipes, but this one will show what "tannins" do )

My previous post recommended over - oaking and under oaking various test jars and verying the time spent on oak for each, so you could get a variety to drink young and one to mature for some years, plus a knowledge of the comparisons between each type of oak and their tannic contribution over what times of exposure to the spirit.

[still_stirrin]

5 - This was a fun and personally rewarding experiment. I plan to toast a sample of these woods and try this test all over again.

Good experiment Otis.

Next step is to try the aging with a spirit because the alcohol will wash tannins differently than boiling water even though the tannins are soluable in water.

I’ve used apple and cherry woods for aging. The cherry produces a slightly red color, like your experiment shows. But I noticed a soft sweetness (reminiscent of sweet cherries) in the whiskey. It was tasty and enjoyable although tradition somewhat does call for oak wood. The finish was clean without any residual astringency.

I’ve also used the apple woods as well. It did give more color than oak early in the process. And I noted a spiciness in the taste resulting from the apple wood. It did not carry the fruitiness from the fruit to the aging jar however. It did finish dry although not astringent, or puckeringly so.

Also, I much enjoyed the pecan wood aged whiskey too. I taste a butternut flavor in it. And the finish was quite smooth. Very “user friendly”.

So many experiments....so little time. Don’t you just love this hobby?

Keep up the good work Otis. And keep bringing us the documented results of your endeavors. It is very much “value added”.
ss

[OtisT]

This a short follow up on the tea tasting I did with the various woods because after the tea has sat a week there are some changes.

The big change was with the Apple wood tea. I can now smell sweet/fruity apple in the Apple tea now, where before I could not detect anything.

The Plum and Cherry continue to smell wonderfully of their fruit.

I am surprised that I can actually smell each fruit from those trees in their wood. The Apple took some time, the Plum took a little patience, while the Cherry was up fron from the get go. For some reason, I did not think it would be this obvious. I think maybe this may be because the last time I worked with fruit wood it was from the lumber yard, and I don’t think they are using the same species of tree I seasoned. Next time I get a chance to pick up more fruit wood from my friends growing them, I am all over it.

The oaks both smell good. With the smell I associate with wet oak subsided a bit, I can really detect more subtle notes in each. Both are sweet and smell of oak in their own way. The Oregon Oak definitely has a unique and light fruity/floral sent that is wonderful. It is a smell I know, but I can’t put a name to yet. I’ll keep smelling until I figure this out.

Otis

[Pikey]

........ I’ll keep smelling until I figure this out.

Otis

Shower ?

[OtisT]

Good experiment Otis. Next step is to try the aging with a spirit because the alcohol will wash tannins differently than boiling water even though the tannins are soluable in water.

And here is the Next Step......

This is the next test in my quest to compare tannin levels between my samples of Oregon Oak and American White Oak. I am using raw, untoasted, samples of the wood chiseled into chips to speed up the process. The spirit used is 62% ABV vodka.

Raw Oak in Vodka - American White Oak and Oregon Oak

These samples have been soaking for 3 weeks. I vacuumed the jars several times to soak the wood quickly. The American White Oak (AWO) is darker than the Oregon Oak (OO).

Diluted to 20% ABV
OO had no bitterness and no astrigency.
AWO had a medium intensity bitter taste and no astrigency.

Diluted to 40% ABV
OO had a light bitter taste and no astrigency.
AWO had a medium bitter taste and it was a little astringent.

This test matches my Tea results, showing that my Oregon Oak appears to contain less tannins than my American White Oak.
Or at least that my OO is less willing to give up the tannins it has.

I will test these samples again in a few months to see if these results change any.

Otis