May one whip icing or ice cream on Shabbos?
May one make mayonnaise on Shabbos?
May one make instant foods through mixing water and a powder together, such as instant mashed potatoes/porridge/rice?
All instant food powders such as mashed potato mix, and the like, which are only edible when mixed with water may not be made on Shabbos into a thick mixture. However one may make it into a thin mixture together with the required irregularities, as defined above. [However there are Poskim which prohibit making instant potato mix even into a thin batter under the basis that they nevertheless stick to each other.]
May one make instant pudding or Jell-O?
When making a bottle for an infant from milk powder must it be made with the required irregularities?
If the milk powder will dissolve immediately upon adding the liquid to it, then it is allowed to be made without any irregularities [although according to some doing so would involve a Nolad prohibition, and thus although one may be lenient it is proper if possible to prepare this mixture from before Shabbos.]
However if the powder will not dissolve right away and will become a semi thick mixture in the interim of it dissolving into the liquid, then it may only be made with the above mentioned irregularities. Others however rule even in such a case one may do so in the normal way.
Due to the cooking prohibition one is only to use water from a Keli Shelishi, or water which is poured from a keli Sheiyni.
When adding liquid into cocoa powder and the like must one do so with an irregularity?
See above Q&A.
May one make Techina on Shabbos?
Adding water to pure Techina: It is forbidden to make a normal texture of Techina by placing water to pure Techina, if the Techina did not have water mixed into to it before Shabbos.  It is however permitted to add a large amount of water simultaneously to the Techina and make it into a thin mixture, provided one does so with the above mentioned forms of irregularities.
Adding more water to a Techina dip: If water was mixed into the Techina from before Shabbos and one now desires to make it thinner, it is allowed to do so if the Techina will not thicken in the interim. Nevertheless one may only mix the water using ones hands rather than a spoon.
Thickening it: If the Techina is too liquidly it remains forbidden to add any Techina or other food to the mixture to make it thicker.
May one make oatmeal on Shabbos?
It is forbidden to make it into a thick batter even using cold water. However one may make it into a thin mixture using an irregularity, as defined above. In all cases one may not use hot water even of a Keli Shelishi due to the cooking prohibition.
May one mix mayonnaise/oil/honey into cut fruits/vegetables and foods of the like?
Cut large: The kneading prohibition only applies when the two substances are being mixed in a way that they join and stick to each other forming one entity, as is the case with dough which is a mixture of flour and water, or with cooked oatmeal. Thus whenever solids are large enough to prevent this form of unity in their mixture, and it is rather that the liquid cotes over the solids, or that the solids are submerged within the liquids, then it is allowed. One may thus pour oil over his vegetable salad and cases of the like.
Cut small: However if the pieces are cut small enough that the addition of the liquid will combine and unite with the solids to form one food then this is forbidden [unless made into a thin batter using an irregularity]. [See footnote for explanation and for a list of vegetables which may be allowed even if cut small]
Cooked fruits/vegetables: There are opinions which say that cooked foods which are now soft and easily mash-able do not contain the kneading prohibition and thus one may add liquid to them and knead the liquid into it even into a thick batter, using the regular methods. According to them one may thus add any liquid to mashed potatoes, or to cut pieces of cooked potatoes even if doing so makes it into a thick batter.
May one knead gravy into mashed potatoes?
Yes as the potatoes have already been kneaded with water when cooked.
May one make thousand island dressing on Shabbos? May one mix mayonnaise with ketchup?
Seemingly this is allowed to be done so long as one mixes the ingredients slowly. However according to the ruling of some Poskim regarding mixing honey with cream cheese, seemingly in their opinion here too it would be forbidden.
May one make an egg salad with mayonnaise on Shabbos?
One may do so using an irregularity. Thus he is to first place in the mayonnaise and then the eggs, as well as he is to mix it [using his fingers or by shaking the bowl, and if this is not possible then he may] with a spoon back and forth and opposed to in a circular motion. It is preferable to remove the spoon between each time.
May one mix mayonnaise into tuna fish on Shabbos?
Seemingly this should have the same status as egg salad.
Does mashing a banana and the like contain a kneading prohibition?
No –See above Halacha 1 Q&A. Nevertheless mashing contains a grinding prohibition and may only be done in ways explained in “The laws of Grinding”-See There!
May one knead liquid into a mashed banana?
The Ketzos Hashulchan allows this to be done with an irregularity for the reason that doing so before Shabbos would ruin the banana, and thus in such a case one may be lenient like the first opinion mentioned above which allows kneading with an irregularity foods which are not knead-able.
The Chazon Ish however rules that liquid may not be added to bananas.
May one mix a batch of lemon aid or other juice very quickly with a spoon?
Yes. See above Halacha 1 Q&A.
May one mix sugar with cocoa powder?
So long as no water is added this is allowed as the substances do not stick to each other and is thus not considered kneading.
May one add soup to his rice/lentils/chulent if doing so will make it into a thick batter?
Yes this may be done even if the food is dry, as explained in Halacha 5 Q&A.
May one combine honey with cream cheese?
May one combine two different yogurts, or yogurt with soft cheese?
Some rule this may be done so long as one makes it into a thin batter using the mentioned irregularities.
May one break biscuits into his yogurt?
This may be done so long as either a) the biscuits are broken to slightly large pieces [as opposed to crumbs] or b) the biscuits are broken small but the mixture will form a thin batter and is done with an irregularity.
May one add sugar to soft cheese or yogurt?
One may not add sugar to soft cheese as doing say may thicken the mixture and turn it into a thick batter. However one may add it into yogurt, being that it makes it thinner.
May one combine cocoa powder with butter or margarine? 
No as doing so forms a thick mixture.
May one pour liquid onto loose earth? May one urinate over earth?
Even if doing so does not contain a planting prohibition [as is the case with urine being that it does not sew the ground] doing so is forbidden due to the kneading prohibition. However it is permitted to do so over thick earth if doing so does not contain a planting prohibition. It is thus permitted to urinate on thick earth.
Sand/Ash: It is forbidden to urinate or pour liquids over sand, ash and all items of the like.
May one urinate onto mud?
If the mud is very liquidly, like a mud puddle than this is allowed. If however the mud is still slightly thick, it is forbidden to be done. Furthermore even if the mud is hard and dry it is forbidden as the mud will soften due to the urine.
May one spit into a vessel or area which contains sand/dirt?
May one cover liquid [such as urine] with sand/dirt?
One may only do so with a large ratio of dirt/sand over water to the point that the mixture will not form a knead-able substance.
 SSH”K 11/31 in name of Rav SZ”A; Betzeil Hachachmah 2/26
 This is forbidden due to it being similar to making “Yaynmulin” which is a mixture of wine peeper and oil, of which it is forbidden to beet and then strain due to it being a great trouble. [See Magen Avraham 321/25] It is likewise forbidden due to Molid-forming a new matter on Shabbos. [SSH”K ibid]
 As the prohibition is not due to kneading. In truth however making ice cream into a thick batter would certainly transgress also the kneading prohibition.
 Tzitz Eliezer 12/32; SSH”K 11 footnote 128
 As it is forbidden to beat an egg on Shabbos. [Magen Avraham 321/24]
 Piskeiy Teshuvos 321/8
 Igros Moshe 4/74 Lash 12; Shmiras Shabbos Kihilchasa chapter 8 Halacha 25, in the name of the Chazon Ish [Orach Chayim 56/9]. Vetzaruch Iyun Gadol as why here even a thin batter is prohibited. Even the Mishneh Berurah himself [chapter 337/52], to whom they mention in the footnote only says that to make it thick is forbidden, as well as in all cases the food somewhat sticks together, and under what basis can one prohibit it?
 Beir Moshe 6/45; Sheivet Halevy 7/41
 As doing so forms a thick mixture which is forbidden to be done on Shabbos. Furthermore, some prohibit doing so due to Nolad.
 See Igros Moshe 4/74 Lash 12 which allows making pudding into a thin batter.
 SSH”K 8/18
 As it does not resemble in any way the concept of kneading, as explained in Halacha 2 in Q&A there with regards to the definition of a thin batter. It is only when there is some thickness to a mixture that it is within the kneading requirements of an irregularity
 As rules Rav Farkash with regards to instant coffee. See The laws of cooking Halacha 12 Q&A there!
 Vetzaruch Iyun how this case is any different than any case in which the added liquid at first thickens the food and only after further mixing does it thin it out, of which was explained in Halacha 3 Q&A that it is forbidden to do so. Perhaps however the difference is that here one has no intent to knead the powder but to dissolve it and thus it is considered a Pisek Reishe, of which we are lenient in being that anyways according to one opinion this is always allowed with an irregularity. However by cases where one intends to knead the food, then although his intent is to make it into a thin batter nevertheless since it becoming a thick batter also serves his use, it is not allowed. See SSH”K 8 footnote 61.
 Igros Moshe 4/74 Lash 1
 See SSH”K 18 and 24 and footnote 56. Vetzaruch Iyun why they did not mention explicitly that if it does not dissolve right away an irregularity is to be used, as they wrote by milk powder.
 SSH”K [new edition]
 This would be forbidden according to all, being that Tehina is a knead-able food which kneads even by simply placing water in it, as explained in Halacha 1 regarding sesame seeds. [See Ketzos Hashulchan 130 footnote 18]
 See above Q&A regarding the definition of a thin batter.
 Place the ingredients together in opposite order and not mix the matter as is usually done with a spoon or fork.
 Shabbos Kehalacha p. 73
 Ketzos Hashulchan 130/6 footnote 19, SSH”K 8/
 This ruling is based on Taz 321/12 which rules that the allowance to cut vegetables small and then add liquid to them is only in accordance to the first opinion being that vegetables are not a knead-able food however according to the second opinion this would be forbidden, [unless made into a thin batter with an irregularity]. Thus since we rule like the stringent opinion it would be forbidden for us to make a thick mixture of radish. Nevertheless many are accustomed to be lenient by radishes even if they are cut small. The Taz there writes the reason for this being due to that if one were to make the mixture before Shabbos its taste would be ruined, and it was therefore allowed to do so on Shabbos with an irregularity, relying on the first opinion above. The Ketzos Hashulchan [ibid] as well suggests that perhaps the reason for this leniency by radishes is because the concept of kneading only applies by foods which will stick together to the liquid, such as garlic and the like. However solid vegetables, even when very small, which will not form a real combination with a liquid would be allowed to be mixed even into a thick batter. In any event this is certainly not the opinion of the Taz which mentions explicitly the case of radishes as a case of kneading. The Ketzos Hashulchan [ibid], based on the Taz and Shevisas Hashabbos, rules that by radishes one may be lenient however not by horseradish/beats or any vegetable which secrets a juice which will cause the mixture to stick.
 SSH”K 8/19-See above Halacha 5 Q&A
 As ketchup with mayonnaise are both semi liquids and thus are not subject to kneading which is with a liquid and a solid.
 Shabbos Kehalacha 7/61
 Although a thick mixture is made since this is un-kneadable material [which according to the first opinion may always be made with an irregularity] and it is unclear if this form of mixture contains at all a kneading prohibition, we are thus lenient [like the first opinion] to allow making it on Shabbos.
 So I saw ruled in the name of Rav Shternbuch
The leniencies of tuna is that it is unclear if it is at all a material which contains a kneading prohibition. Furthermore, all tuna comes with either water or oil, and is hence considered kneaded before Shabbos to which one may add more liquids on Shabbos. [See above Halacha 4 Q&A]
 SSH”K 8/3
 Ketzos Hashulchan 130 footnote 19 and SSH”K 8/14
 SSH”K 8/5
 Ketzos Hashulchan 130 footnote 12
 SSH”K 8/13
 Rav Avraham Elyashvili
 As in their opinion these kneading only applies by a solid with a liquid and not by two semi-liquids. Perhaps however there is difference between whether the cream cheese and honey is thick or thin.
 SSH”K 8/12
 SSH”K 8/12
 Igros Moshe 4/74 Lash; Rav Avraham Elyashvili mentioned in Rav Gadasi’s Hilchos Shabbos
 As in their opinion these kneading only applies by a solid with a liquid and not by two semi-liquids.
 SSH”K 8/16
 SSH”K 8/17
 Ketzos Hashulchan 130/8
 Ketzos Hashulchan 130/8
 So questions Peri Megadim, brought in M”B 321/57 Shaareiy Tziyon 66
 As it is considered a Piseik Reisha Delo Nicha Lei.
 Ketzos Hashulchan 130/8 footnote 22
 As the Peri Megadim leaves this matter in question. According to the second opinion mentioned above even entering liquid into a material constitutes kneading. The Peri Megadim leaves in question if even here this would be a problem being that by here he has no intent to knead the material with his saliva, and it’s a case of “Pisek Reshei Dilo Nicha Lei”.
 So rules Ketzos Hashulchan based on that a) spitting is an irregularity and thus only Rabbinical. B) The amount that can be mixed is less than the Biblical amount needed to transgress kneading. C) Naturally saliva does not sink into material but rather floats over it.
 Ketzos Hashulchan 130/8
 So rules Chayeh Adam and M”B.