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Processing Tomatoes, skin+seeds vs. not

When processing tomatoes for freezer stash I have always followed the traditional method of removing the skin and seeds before packing. On another thread here, someone pointed out an adored brand of canned pizza/Italian style tomatoes, the description of which specifically stated the skins were left on to preserve that "tomato velvet" just under the skin "where a lot of the flavor resides". Also, prevailing wisdom is that a lot of flavor is contained in the seed smut one would remove with de-seeding.
So my question is, if I am pureeing or at least immersion blendering them once they're out of the freezer and in use, have I unknowingly taken away lots of flavor AND added effort at the processing stage by peeling/seeding?
Is peeling/seeding necessary, in your opinion? Will I get a noticeably more flavorful tomato product by not doing so? Will I regret those cases of bits of skin/seeds in my finished dish? Perhaps seed but not peel or vice versa?
At this point I've done a few pounds with skin and seeds intact and am contemplating doing all the rest of my crop this way. What I have put up so far is peeled/seeded. I'm not crazy about the added layer of decision making I buy into with the some of each approach, so I guess I'm looking for the impetus to decide on one method and stick to it in future seasons.

I'd love to hear opinions.
(Perhaps neither of these approaches is best?)

I grow and process mostly San Marzano and Amish Paste plus a few other varieties, if that matters.

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  1. Not always, but quite often, leaving the seeds in the tomato sauce makes it somewhat bitter so I'd remove the seeds. Leaving the skin intact to preserve the "'velvet" makes me wonder if the person offering that advice peels the tomato cold. If you heat the tomato over an open flame or dredge it for a short time in hot water the skin slips off quite easily and leaves the "velvet". I would peel, remove the seeds, and continue normal processing form there.

    1. I grow San Marzanos too. I (also) don't can them, but freeze them instead. I purée them intact then freeze. I have never had a bitter batch. I think removing the skin and seeds might be better just for canning.
      I also make tomato jam (freezer jam) with them this way. I think the tomato flavor is better with the skin and seeds left in.

      3 Replies
      1. re: sedimental

        Thank you both for the replies. Do either of you think the issue of seeds and bitterness could be related to variety? Todao, can I ask if your comments about bitterness are based on personal experience? I know it's prevailing wisdom, but I am a questioner of everything and take that with a grain of salt until proven or disproven by my (or other chowhounders) experience. I'm honestly not sure I've ever experienced the seeds=bitterness thing, but I know SM's and similar varieties are known for having small and few seeds compared to others.

        WRT the "tomato velvet" concept, I found that statement on the website of a commercial brand of canned tomatoes and then started paying more attention to my own method. There is definitely a residue of tomato flesh left on the skin after removal following boiling water dip. The amount seems to depend at least a little on how long the dip lasts. And then one is losing some of what remains on the tomato to the handling involved in halving and seeding...

        I can definitely see why peeling/seeding is preferred for canning. My canned tomatoes end up looking kind of spooky because I heat them as minimally as possible prior to packing and they separate in the jar. Someone gifted me a jar of canned that had either not been seeded at all or not thoroughly seeded, and those were sad AND spooky looking with the impression of having been sloppily prepared. OTOH I'm obsessive and very visually oriented and they tasted just fine.

        1. re: splatgirl

          Question everything!!! That's a valuable philosophy with which I agree entirely.
          Yes, my reference to bitterness is based on personal experience but I must admit that there are more varieties of tomatoes than there are dogs in Cesar Millan's pack of mongrels so I couldn't definitively say that all tomato seeds offer bitterness. However, based on what I've experienced and somewhat intuitively, I've just developed the habit of seeding them for certain recipes; like sauces.
          I might suggest that you remove the seeds from three or four of the tomatoes you'll be using and chewing them up to determine if they are in fact bitter.
          While I did suggest a heated water bath for making tomatoes easier to peel, I did so out of respect for the many home cooks on the forum who may want an easy method for doing the job. Personally, I don't use a water bath - I use an open flame from the burner on my gas range while holding them with a fondue fork. I heat them as evenly as possible and as soon as the skin splits I get the peel off. You can feel the "velvet" on the outer flesh (they're even kind of slippery) and if there's any remaining on the inner side of the skins I just don't worry about it. I'd rather suffer the loss of a bit of velvet than have skins in my finished product.

          1. re: todao

            Thank you.
            I've done about six pounds this afternoon via a whole new branch of the decision making tree.
            I did not peel. I seeded, reserving the seeds and goo in a strainer over a bowl. I forced the goo through so all that was left to discard (or save!) was a thick mass of seeds. I spooned the harvested liquid back into the freezer bags before sealing. I got about 2 cups of liquid from ~6 lbs. of a mix of SM, Amish paste and a few Ponderosas.

            Novelli, thanks for your comments below. Do you think the thickening/pectin/yum is from the seeds themselves or the goo?

            One of my default methods for a fresh sauce for wood-fired pizza is thaw, drain, reduce drained liquid, add back to flesh, puree. This gives an intense tomato-y flavor while retaining the brightness of the fresh tomato that I seek, and the freezing works in my favor by because it breaks down the cell walls and releases the liquid. I find this method produces a product that is far superior to even one made from just-picked tomatoes, so it's a win on all fronts.
            Anyway, barring just not seeding at all, being able to retain all that juicy goo seems like reason enough to go the strained seed route, especially now that I've seen how much yum has been ending up in my slop bowl by not doing so.

            I also made it a point to eat some seeds from all of the varieties. The SM's did have a distinct lack of presence vs. the Amish Paste, which were bigger, harder and a little unpleasantly textured. Neither tasted bad, but perhaps that changes with cooking and pureeing.

      2. I grow San Marzanos and can them peeled, but whole (if anything, maybe a bit crushed).
        I don't seed them, because to me, that gelatinous tomato pectin is one of the greatest things in the world. Full flavor and adds a wonderful consistency/thickness to the finished sauce.

        Although, when I do make a sauce with them, I will cook them with the seeds, but run it all through a food mill to remove them (or as many as I can) once done.

        1. I can and freeze both. I use all kinds of tomatoes for each, and I never, ever, seed the tomatoes. Whether or not I peel them depends on what I am doing. Since I don't have wide mouth jars, and am not willing to have 2 sets of rings and lids and jars, I don't can whole tomatoes (I also usually have too many different sizes at a time to can whole). These are the products I make every year:

          Canned crushed tomatoes: Peel, quarter, cook until hot, pressure can with a little salt.

          Canned salsa: Roasted unpeeled tomatoes, peppers, onions, lemon juice. Pressure can because I don't want to mess with worrying about acidity, and I don't want to make a very tart salsa.

          Roasted unpeeled tomato halves, with garlic or onions. Freeze in 1 qt ziploc bags. Use on hot pasta as a stand alone sauce, or puree and use as a base for a fancier sauce.

          Frozen unpeeled whole tomatoes. Not very many of these, because they take up a lot of room in the freezer. But they are nice to use in Indian cooking where 1 or 2 tomatoes are used as a background addition. Like pulao. They do peel easily when partially thawed, but I don't always bother.

          1. I do peeled, but not seeded. I've decided I don't like the peels in my sauces.

            1 Reply
            1. re: jaykayen

              Same here. I freeze my tomatoes, no peel, with seeds. I deal with the seeds later if I don't want them in a particular recipe.

            2. I appreciate all of the replies. It makes me feel better to know that people are happy with skins or skins+seeds left intact. I've got representative batches from each method stashed in the freezer, so hopefully when tomato season rolls around next summer I'll have decided on an ideal.

              1 Reply
              1. re: splatgirl

                just wanted to add - I grew up with tomato canning at home every summer - we always gave the tomatoes a quick dip - pealed, but did not seed. Personally I think the seeds are bitter, but they can be removed at the time of use - I think you lose too much flavor removing before canning if you are processing whole tomatoes. Also if you dip too long you will lose too much tomato flesh - make sure to pull the tomatoes out fast and put in cold water to stop the cooking.

                these days I just make tomato sauce, not whole canned tomatoes. I use an attachment to my kitchenaid that strains out the skins and seeds very effectively without losing any of the juice or flesh. Its not fast, but it does what I want (a small version of one of those big italian tools. I I just quarter and cut out bad spots before running the tomatoes through,, avoiding the whole dipping step. Im very satisfied. The sauce then cooks down slowly to about half the original volume, with a little olive oil and a bit of garlic clove. Its very flavorful and can be either canned or frozen at this point.

              2. Recall back in history of the USA that the Early Settlers grew tomatoes for the beauty of the Orbs of Red. But they thought that those beautiful fruits were poisonous to eat. We have come a long way!

                Also recall that “A little bit of Bitter” can be a good thing. Have you ever tasted Vanilla extract Straight out of the bottle: talk about Bitter! Also, when one wants to make a tropical drink full of citrus juices and sugar, that the whole mixture tastes better with a Splash of Grapefruit Juice? Similarly, there is a reason for the use of the so-called “Bitters” in many cocktails; just a few drops at a time.

                So, my point is: Could there be Value in including the tomato seeds in a sauce?

                Likewise, what is the problem with the peels?

                Can one simply assess the tomatoes, cut out the flaws, cut out the core and blossom end, and then put them in the Cuisinart, and just Pummel them? Then you can add the result to your ”mirapois” , or garlic-onion-celery-carrot saute mixture of your choice?

                Then put it in a Zip-lock bag and freeze it for use as a base for pasta sauce or chili in the middle of Winter, while reading seed catalogs and dreaming of Spring?

                1. I guess I just have to concede that the perfect processing method depends on intended use. Maybe the best cover-all answer for my needs is to freeze whole and realize that it's not the end of the world if I have to remove seeds and/or peels from thawed tomatoes before using them.

                  I can be totally fine with skin left on if the finished product is a puree especially if it makes for a more flavorful product, but more often than not, I am NOT pureeing. I also don't hate the presence of seeds and I completely agree with the comments about a bit of bitterness, but how to predict when too much will be too much? Hours and hours of cooking tomato something to turn bitterness into that wonderful complexity is not what I do most.
                  But here's another thing--I processed about 7 pounds yesterday and, since I had decided I would skinning and seeding (saving the juice and goo as I mentioned previously), made a point to sample the skins of each variety. What I learned is that some skins are bitter, which I hadn't considered before. In particular from this batch, a variety from my CSA share that looked like a big Roma. These skins were quite bitter and tough and inedible. I wouldn't want a whole pot full of those under any circumstances. OTOH, the SM skins were much more tender and tasted fine, and if it weren't for wanting a crushed product vs puree, I'd be happy with leaving them on.

                  4 Replies
                  1. re: splatgirl

                    Thanks, splatgirl

                    Very interesting. I had no idea that the SKINS, as opposed to the seeds, imparted Bitterness. All my life, I have eaten tomatoes with the skins on: in salads, on sandwiches, or just out of hand, etc. All of them are in the Raw state, however.

                    Now, are you implying that the cooking led to the Bitterness?

                    Also can you explain your abbreviations, please.:

                    Namely : CSA

                    and OTOH

                    Thank you for your input.


                    1. re: Janocase

                      The bitter skins were removed from some paste-type tomatoes that came from my Community Supported Agriculture (CSA) farmshare. They were just given a dip in boiling water, not cooked. I did not notice any bitterness from the skins of the other two or three varieties I was packing that day. I am going to make a point to taste some from every batch from now on, though, as certainly it depends on variety but I suspect also growing conditions.

                      My plan going forward is to feel fine about carrying on with peeling before packing and only do the whole, unskinned, unseeded if I am in a big hurry since I would only want to use those for a long-cooked, pureed product. There really is hardly anything at all left on the skins once they've been removed, regardless of the variety so I will quit worrying about that.

                      If nothing else, this thread encouraged me to start sieving the seeds and goo and put all of that back in with the fruits--it really amounts to a lot of super tasty liquid. I'd guess I had ~3c. from 7 lbs. of skinned tomatoes.

                      OTOH= on the other hand

                      1. re: splatgirl

                        there is some bitterness in tomato skin as in many foods but Id say not as to notice in most - I always eat the whole thing where fresh tomatoes are concerned. The seeds are discernabily bitter if you bite into them - so worth removing if you are going to puree and cook down the tomatoes., etc. makes a difference in a sauce.

                        1. re: jen kalb

                          I was planning to make some Chili, with ground turkey, but no beans, and freezing it. So this qualifies on two counts (ie, long cooking, and adding spices) for me to leave both seeds and skin. (I admit, I am a Lazy Lass)

                          (Thanks for the explanations of the abbreviations, and bringing me gently into the 21st Century)

                          WRT growing conditions: I cannot count on any climate explanations. Here in the Northern Illinois, there has been a severe heat wave and drought, so nothing is reliable. Now it is unseasonably cool, so the rest of the tomatoes on the vines are delayed in their ripening speed, Go figure.